本專案是 .NET 基金會的一部分，並遵守其行為準則。

您的 Stars 或捐款可以讓 MiniExcel 更加完善

簡介

MiniExcel 是一款簡單且高效的 .NET Excel 處理工具，專為降低記憶體使用量而設計。

目前，大多數主流框架需要將 Excel 文件中的所有資料載入記憶體以便操作，但這可能會造成記憶體消耗問題。MiniExcel 採用不同的方法：以串流方式逐行處理資料，將原本可能高達數百 MB 的消耗降至僅需數 MB，有效防止記憶體不足（OOM）問題。

flowchart LR
    A1(["Excel analysis
process"]) --> A2{{"Unzipping
XLSX file"}} --> A3{{"Parsing
OpenXML"}} --> A4{{"Model
conversion"}} --> A5(["Output"])
    B1(["Other Excel
Frameworks"]) --> B2{{"Memory"}} --> B3{{"Memory"}} --> B4{{"Workbooks &
Worksheets"}} --> B5(["All rows at
the same time"])
    C1(["MiniExcel"]) --> C2{{"Stream"}} --> C3{{"Stream"}} --> C4{{"POCO or dynamic"}} --> C5(["Deferred execution
row by row"])
    classDef analysis fill:#D0E8FF,stroke:#1E88E5,color:#0D47A1,font-weight:bold;
    classDef others fill:#FCE4EC,stroke:#EC407A,color:#880E4F,font-weight:bold;
    classDef miniexcel fill:#E8F5E9,stroke:#388E3C,color:#1B5E20,font-weight:bold;    class A1,A2,A3,A4,A5 analysis;
    class B1,B2,B3,B4,B5 others;
    class C1,C2,C3,C4,C5 miniexcel;

功能特色

最小化記憶體消耗，防止記憶體不足（OOM）錯誤並避免完整垃圾回收
支援即時、逐列資料操作，在大型資料集上獲得更佳效能
支援 LINQ 延遲執行，實現快速且省記憶體的分頁及複雜查詢
輕量級，無需安裝 Microsoft Office 或 COM+ 元件，且 DLL 檔案小於 500KB
簡單直觀的 API 風格，用於讀取/寫入/填充 Excel

2.0 版預覽

我們正在開發下一代 MiniExcel 版本，將會有全新模組化且聚焦的 API、核心與 Csv 功能分開的 nuget 套件、完整支援 IAsyncEnumerable 非同步串流查詢，以及更多即將推出的新功能！這些套件將以預覽版發佈，歡迎大家試用並給予回饋！

如果有興趣，請同時參閱新文件及升級說明。

待辦事項

請檢查 TODO

效能

基準測試的程式碼可在 MiniExcel.Benchmarks 找到。

用於效能測試的檔案是 Test1,000,000x10.xlsx，這是一份 32MB 的文件，包含 1,000,000 行 * 10 列，所有儲存格皆填入字串 "HelloWorld"。

要執行所有基準測試，請使用：

dotnet run -project .\benchmarks\MiniExcel.Benchmarks -c Release -f net9.0 -filter * --join

您可以在這裡找到最新版本的基準測試結果。

Excel 查詢/匯入

#### 1. 執行查詢並將結果對應到強型別的 IEnumerable [[試試看]](https://dotnetfiddle.net/w5WD1J)

建議使用 Stream.Query，因為效率更佳。

public class UserAccount
{
    public Guid ID { get; set; }
    public string Name { get; set; }
    public DateTime BoD { get; set; }
    public int Age { get; set; }
    public bool VIP { get; set; }
    public decimal Points { get; set; }
}
var rows = MiniExcel.Query(path);
// orusing (var stream = File.OpenRead(path))
    var rows = stream.Query();

#### 2. 執行查詢並將其對應到動態物件清單（不使用 head）[[試試看]](https://dotnetfiddle.net/w5WD1J)

dynamic key 是 A.B.C.D..

| MiniExcel | 1 | |-----------|---| | Github | 2 |


var rows = MiniExcel.Query(path).ToList();
// or
using (var stream = File.OpenRead(path))
{
    var rows = stream.Query().ToList();    Assert.Equal("MiniExcel", rows[0].A);
    Assert.Equal(1, rows[0].B);
    Assert.Equal("Github", rows[1].A);
    Assert.Equal(2, rows[1].B);
}

#### 3. 執行查詢並以第一列作為標題 [[試試看]](https://dotnetfiddle.net/w5WD1J)

注意：相同欄位名稱會使用最右邊的那一個

輸入的 Excel：

| 欄位1 | 欄位2 | |-----------|---------| | MiniExcel | 1 | | Github | 2 |


var rows = MiniExcel.Query(useHeaderRow:true).ToList();
// or
using (var stream = File.OpenRead(path))
{
    var rows = stream.Query(useHeaderRow:true).ToList();    Assert.Equal("MiniExcel", rows[0].Column1);
    Assert.Equal(1, rows[0].Column2);
    Assert.Equal("Github", rows[1].Column1);
    Assert.Equal(2, rows[1].Column2);
}

#### 4. 查詢支援 LINQ 擴充方法 First/Take/Skip ...等

查詢 First

var row = MiniExcel.Query(path).First();
Assert.Equal("HelloWorld", row.A);
// orusing (var stream = File.OpenRead(path))
{
    var row = stream.Query().First();
    Assert.Equal("HelloWorld", row.A);
}

MiniExcel/ExcelDataReader/ClosedXML/EPPlus 之間的效能比較 queryfirst

#### 5. 依工作表名稱查詢

MiniExcel.Query(path, sheetName: "SheetName");
//or
stream.Query(sheetName: "SheetName");

#### 6. 查詢所有工作表名稱及行數

var sheetNames = MiniExcel.GetSheetNames(path);
foreach (var sheetName in sheetNames)
{
    var rows = MiniExcel.Query(path, sheetName: sheetName);
}

#### 7. 取得欄位

var columns = MiniExcel.GetColumns(path); // e.g result : ["A","B"...]var cnt = columns.Count;  // get column count

#### 8. 動態查詢將資料列轉型為 IDictionary

foreach(IDictionary row in MiniExcel.Query(path))
{
    //..
}// or
var rows = MiniExcel.Query(path).Cast>();
// or Query specified ranges (capitalized)
// A2 represents the second row of column A, C3 represents the third row of column C
// If you don't want to restrict rows, just don't include numbers
var rows = MiniExcel.QueryRange(path, startCell: "A2", endCell: "C3").Cast>();

#### 9. 查詢 Excel 並返回 DataTable

不建議這麼做，因為 DataTable 會將所有資料載入記憶體，這樣會失去 MiniExcel 低記憶體消耗的特性。

``C# var table = MiniExcel.QueryAsDataTable(path, useHeaderRow: true);


#### 10. 指定開始讀取資料的儲存格

csharp
MiniExcel.Query(path,useHeaderRow:true,startCell:"B3")
#### 11. 填充合併儲存格
注意：相較於「不使用合併填充」效率較慢
原因：OpenXml 標準將 mergeCells 放在檔案底部，導致需要對 sheetxml 進行兩次遍歷csharp
    var config = new OpenXmlConfiguration()
    {
        FillMergedCells = true
    };
    var rows = MiniExcel.Query(path, configuration: config);
支援變長與變寬的多列多欄填充
#### 12. 透過磁碟快取讀取大型檔案（磁碟快取 - SharedString）
如果 SharedStrings 的大小超過 5 MB，MiniExcel 預設會使用本地磁碟快取，例如，10x100000.xlsx（一百萬筆資料），當停用磁碟快取時，最大記憶體用量為 195MB，但啟用磁碟快取只需 65MB。注意，此優化會有一些效能成本，因此在這種情況下，讀取時間會從 7.4 秒增加到 27.2 秒。如果你不需要這個功能，可以用下列程式碼關閉磁碟快取：csharp
var config = new OpenXmlConfiguration { EnableSharedStringCache = false };
MiniExcel.Query(path,configuration: config)
您可以使用 SharedStringCacheSize 來更改 sharedString 檔案大小，超過指定大小時將進行磁碟快取
csharp
var config = new OpenXmlConfiguration { SharedStringCacheSize=50010241024 };
MiniExcel.Query(path, configuration: config);
建立/匯出 Excel  
必須是具有公有無參數建構子的非抽象型別。
MiniExcel 支援 IEnumerable 參數的延遲執行，如果您想使用最少的記憶體，請不要呼叫如 ToList 等方法
例如：ToList 或不使用記憶體
#### 1. 匿名型別或強型別 [[試試看]](https://dotnetfiddle.net/w5WD1J)
csharp
var path = Path.Combine(Path.GetTempPath(), $"{Guid.NewGuid()}.xlsx");
MiniExcel.SaveAs(path, new[] {
    new { Column1 = "MiniExcel", Column2 = 1 },
    new { Column1 = "Github", Column2 = 2}
});
#### 2. IEnumerable>csharp
var values = new List>()
{
    new Dictionary{{ "Column1", "MiniExcel" }, { "Column2", 1 } },
    new Dictionary{{ "Column1", "Github" }, { "Column2", 2 } }
};
MiniExcel.SaveAs(path, values);
建立檔案結果：
| 欄位1     | 欄位2   |
|-----------|---------|
| MiniExcel | 1       |
| Github    | 2       |

#### 3.  IDataReader
建議使用，可以避免將所有資料載入記憶體

csharp
MiniExcel.SaveAs(path, reader);
DataReader 匯出多個工作表（建議使用 Dapper ExecuteReader）csharp
using (var cnn = Connection)
{
    cnn.Open();
    var sheets = new Dictionary();
    sheets.Add("sheet1", cnn.ExecuteReader("select 1 id"));
    sheets.Add("sheet2", cnn.ExecuteReader("select 2 id"));
    MiniExcel.SaveAs("Demo.xlsx", sheets);
}
#### 4. 資料表格不建議使用，因為它會將所有資料載入記憶體
DataTable 會優先使用 Caption 作為欄位名稱，然後才使用欄位名稱
csharp
var path = Path.Combine(Path.GetTempPath(), $"{Guid.NewGuid()}.xlsx");
var table = new DataTable();
{
    table.Columns.Add("Column1", typeof(string));
    table.Columns.Add("Column2", typeof(decimal));
    table.Rows.Add("MiniExcel", 1);
    table.Rows.Add("Github", 2);
}
MiniExcel.SaveAs(path, table);
####  5. Dapper 查詢感謝 @shaofing #552，請使用 CommandDefinition + CommandFlags.NoCache
csharp
using (var connection = GetConnection(connectionString))
{
    var rows = connection.Query(
        new CommandDefinition(
            @"select 'MiniExcel' as Column1,1 as Column2 union all select 'Github',2"
            , flags: CommandFlags.NoCache)
        );
    // Note: QueryAsync will throw close connection exception
    MiniExcel.SaveAs(path, rows);
}
以下程式碼將把所有資料載入記憶體csharp
using (var connection = GetConnection(connectionString))
{
    var rows = connection.Query(@"select 'MiniExcel' as Column1,1 as Column2 union all select 'Github',2");
    MiniExcel.SaveAs(path, rows);
}
#### 6. SaveAs 到 MemoryStream  [[試試看]](https://dotnetfiddle.net/JOen0e)
csharp
using (var stream = new MemoryStream()) //support FileStream,MemoryStream ect.
{
    stream.SaveAs(values);
}
例如：導出 Excel 的 APIcsharp
public IActionResult DownloadExcel()
{
    var values = new[] {
        new { Column1 = "MiniExcel", Column2 = 1 },
        new { Column1 = "Github", Column2 = 2}
    };
    var memoryStream = new MemoryStream();
    memoryStream.SaveAs(values);
    memoryStream.Seek(0, SeekOrigin.Begin);
    return new FileStreamResult(memoryStream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
    {
        FileDownloadName = "demo.xlsx"
    };
}
#### 7. 建立多個工作表
csharp
// 1. Dictionary
var users = new[] { new { Name = "Jack", Age = 25 }, new { Name = "Mike", Age = 44 } };
var department = new[] { new { ID = "01", Name = "HR" }, new { ID = "02", Name = "IT" } };
var sheets = new Dictionary
{
    ["users"] = users,
    ["department"] = department
};
MiniExcel.SaveAs(path, sheets);
// 2. DataSet
var sheets = new DataSet();
sheets.Add(UsersDataTable);
sheets.Add(DepartmentDataTable);
//..
MiniExcel.SaveAs(path, sheets);

#### 8. 表格樣式選項
預設樣式
無樣式設定csharp
var config = new OpenXmlConfiguration()
{
     TableStyles = TableStyles.None
};
MiniExcel.SaveAs(path, value,configuration:config);

#### 9. 自動篩選從 v0.19.0 開始，OpenXmlConfiguration.AutoFilter 可以啟用或停用自動篩選，預設值為 true，設定自動篩選的方法如下：
csharp
MiniExcel.SaveAs(path, value, configuration: new OpenXmlConfiguration() { AutoFilter = false });
#### 10. 建立映像檔csharp
var value = new[] {
    new { Name="github",Image=File.ReadAllBytes(PathHelper.GetFile("images/github_logo.png"))},
    new { Name="google",Image=File.ReadAllBytes(PathHelper.GetFile("images/google_logo.png"))},
    new { Name="microsoft",Image=File.ReadAllBytes(PathHelper.GetFile("images/microsoft_logo.png"))},
    new { Name="reddit",Image=File.ReadAllBytes(PathHelper.GetFile("images/reddit_logo.png"))},
    new { Name="statck_overflow",Image=File.ReadAllBytes(PathHelper.GetFile("images/statck_overflow_logo.png"))},
};
MiniExcel.SaveAs(path, value);
#### 11. 位元組陣列檔案導出自 1.22.0 起，當值類型為 byte[] 時，系統會預設在儲存格中保存檔案路徑，匯入時系統可自動轉換為 byte[]。若不想啟用此功能，可將 OpenXmlConfiguration.EnableConvertByteArray 設為 false，這樣可以提升系統效能。
自 1.22.0 起，當值類型為 byte[] 時，系統會預設在儲存格中保存檔案路徑，匯入時系統可自動轉換為 byte[]。若不想啟用此功能，可將 OpenXmlConfiguration.EnableConvertByteArray 設為 false，這樣可以提升系統效能。
#### 12. 垂直合併相同儲存格
此功能僅支援 xlsx 格式，並會在 @merge 和 @endmerge 標記之間將儲存格垂直合併。
你可以使用 @mergelimit 來限制垂直合併儲存格的範圍。
csharp
var mergedFilePath = Path.Combine(Path.GetTempPath(), $"{Guid.NewGuid().ToString()}.xlsx");
var path = @"../../../../../samples/xlsx/TestMergeWithTag.xlsx";
MiniExcel.MergeSameCells(mergedFilePath, path);
csharp
var memoryStream = new MemoryStream();
var path = @"../../../../../samples/xlsx/TestMergeWithTag.xlsx";
memoryStream.MergeSameCells(path);
合併前後的檔案內容：
無合併限制：
有合併限制：
#### 13. 跳過 null 值
新增明確選項以針對 null 值寫入空白儲存格：csharp
DataTable dt = new DataTable();
/ ... /
DataRow dr = dt.NewRow();
dr["Name1"] = "Somebody once";
dr["Name2"] = null;
dr["Name3"] = "told me.";
dt.Rows.Add(dr);
OpenXmlConfiguration configuration = new OpenXmlConfiguration()
{
     EnableWriteNullValueCell = true // Default value.
};
MiniExcel.SaveAs(@"C:\temp\Book1.xlsx", dt, configuration: configuration);
xml

    
        Somebody once
    
    
    
        told me.
    

先前行為：csharp
/ ... /
OpenXmlConfiguration configuration = new OpenXmlConfiguration()
{
     EnableWriteNullValueCell = false // Default value is true.
};
MiniExcel.SaveAs(@"C:\temp\Book1.xlsx", dt, configuration: configuration);
xml

    
        Somebody once
    
    
        
    
    
        told me.
    

適用於 null 和 DBNull 值。#### 14. 凍結窗格
csharp
/ ... /
OpenXmlConfiguration configuration = new OpenXmlConfiguration()
{
    FreezeRowCount = 1,     // default is 1
    FreezeColumnCount = 2   // default is 0
};
MiniExcel.SaveAs(@"C:\temp\Book1.xlsx", dt, configuration: configuration);
填充資料到 Excel 範本 
宣告方式類似於 Vue 模板的 {{變數名稱}}，或集合渲染 {{集合名稱.欄位名稱}}

集合渲染支援 IEnumerable/DataTable/DapperRow
#### 1. 基本填充
範本：
結果：
程式碼：csharp
// 1. By POCO
var value = new
{
    Name = "Jack",
    CreateDate = new DateTime(2021, 01, 01),
    VIP = true,
    Points = 123
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);

// 2. By Dictionary
var value = new Dictionary()
{
    ["Name"] = "Jack",
    ["CreateDate"] = new DateTime(2021, 01, 01),
    ["VIP"] = true,
    ["Points"] = 123
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);
#### 2. IEnumerable 資料填充
注意1：使用相同欄位的第一個 IEnumerable 作為填充列表的依據
範本：
結果：
程式碼：
csharp
//1. By POCO
var value = new
{
    employees = new[] {
        new {name="Jack",department="HR"},
        new {name="Lisa",department="HR"},
        new {name="John",department="HR"},
        new {name="Mike",department="IT"},
        new {name="Neo",department="IT"},
        new {name="Loan",department="IT"}
    }
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);
//2. By Dictionary
var value = new Dictionary()
{
    ["employees"] = new[] {
        new {name="Jack",department="HR"},
        new {name="Lisa",department="HR"},
        new {name="John",department="HR"},
        new {name="Mike",department="IT"},
        new {name="Neo",department="IT"},
        new {name="Loan",department="IT"}
    }
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);
#### 3. 複雜資料填充
注意：支援多工作表並使用相同變數
範本：
結果：
csharp
// 1. By POCO
var value = new
{
    title = "FooCompany",
    managers = new[] {
        new {name="Jack",department="HR"},
        new {name="Loan",department="IT"}
    },
    employees = new[] {
        new {name="Wade",department="HR"},
        new {name="Felix",department="HR"},
        new {name="Eric",department="IT"},
        new {name="Keaton",department="IT"}
    }
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);
// 2. By Dictionary
var value = new Dictionary()
{
    ["title"] = "FooCompany",
    ["managers"] = new[] {
        new {name="Jack",department="HR"},
        new {name="Loan",department="IT"}
    },
    ["employees"] = new[] {
        new {name="Wade",department="HR"},
        new {name="Felix",department="HR"},
        new {name="Eric",department="IT"},
        new {name="Keaton",department="IT"}
    }
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);
#### 4. 填充大數據效能
注意：在 MiniExcel 中，使用 IEnumerable 延遲執行而非 ToList，可以節省最大記憶體用量
#### 5. 儲存格值自動對應型別
範本
結果
類別csharp
public class Poco
{
    public string @string { get; set; }
    public int? @int { get; set; }
    public decimal? @decimal { get; set; }
    public double? @double { get; set; }
    public DateTime? datetime { get; set; }
    public bool? @bool { get; set; }
    public Guid? Guid { get; set; }
}
程式碼csharp
var poco = new TestIEnumerableTypePoco { @string = "string", @int = 123, @decimal = decimal.Parse("123.45"), @double = (double)123.33, @datetime = new DateTime(2021, 4, 1), @bool = true, @Guid = Guid.NewGuid() };
var value = new
{
    Ts = new[] {
        poco,
        new TestIEnumerableTypePoco{},
        null,
        poco
    }
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);
#### 6. 範例：列出 Github 專案
範本

結果
程式碼csharp
var projects = new[]
{
    new {Name = "MiniExcel",Link="https://github.com/mini-software/MiniExcel",Star=146, CreateTime=new DateTime(2021,03,01)},
    new {Name = "HtmlTableHelper",Link="https://github.com/mini-software/HtmlTableHelper",Star=16, CreateTime=new DateTime(2020,02,01)},
    new {Name = "PocoClassGenerator",Link="https://github.com/mini-software/PocoClassGenerator",Star=16, CreateTime=new DateTime(2019,03,17)}
};
var value = new
{
    User = "ITWeiHan",
    Projects = projects,
    TotalStar = projects.Sum(s => s.Star)
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);
#### 7. 分組資料填充csharp
var value = new Dictionary()
{
    ["employees"] = new[] {
        new {name="Jack",department="HR"},
        new {name="Jack",department="HR"},
        new {name="John",department="HR"},
        new {name="John",department="IT"},
        new {name="Neo",department="IT"},
        new {name="Loan",department="IT"}
    }
};
await MiniExcel.SaveAsByTemplateAsync(path, templatePath, value);
##### 1. 同時使用 @group 標籤與 @header 標籤
前
後
##### 2. 僅使用 @group 標籤，未使用 @header 標籤
前
後
##### 3. 未使用 @group 標籤
前
後
#### 8. 在儲存格中使用 If/ElseIf/Else 條件語句
規則：
支援 DateTime、Double、Int 型別與 ==、!=、>、>=、<、<= 運算子。
支援 String 型別與 ==、!= 運算子。
每個語句應該位於新的一行。
運算子前後應加一個空格。
語句內不應有換行。
儲存格必須遵循如下的精確格式。
csharp
@if(name == Jack)
{{employees.name}}
@elseif(name == Neo)
Test {{employees.name}}
@else
{{employees.department}}
@endif
在此之前
之後
#### 9. 以 DataTable 作為參數csharp
var managers = new DataTable();
{
    managers.Columns.Add("name");
    managers.Columns.Add("department");
    managers.Rows.Add("Jack", "HR");
    managers.Rows.Add("Loan", "IT");
}
var value = new Dictionary()
{
    ["title"] = "FooCompany",
    ["managers"] = managers,
};
MiniExcel.SaveAsByTemplate(path, templatePath, value);
#### 10. 公式##### 1. 範例
在你的公式前加上 $，並使用 $enumrowstart 和 $enumrowend 來標記可列舉的開始與結束行：
當模板渲染時，$ 前綴會被移除，$enumrowstart 和 $enumrowend 會被替換為可列舉的開始與結束行號：
##### 2. 其他範例公式：
|              |                                                                                           |
|--------------|-------------------------------------------------------------------------------------------|
| 總和         | $=SUM(C{{$enumrowstart}}:C{{$enumrowend}})                                              |
| 另類平均     | $=SUM(C{{$enumrowstart}}:C{{$enumrowend}}) / COUNT(C{{$enumrowstart}}:C{{$enumrowend}}) |
| 範圍         | $=MAX(C{{$enumrowstart}}:C{{$enumrowend}}) - MIN(C{{$enumrowstart}}:C{{$enumrowend}})   |

#### 11. 其他
##### 1. 檢查模板參數鍵
自 V1.24.0 起，預設會忽略模板中缺失的參數鍵並以空字串取代，IgnoreTemplateParameterMissing 可控制是否拋出異常。
csharp
var config = new OpenXmlConfiguration()
{
    IgnoreTemplateParameterMissing = false,
};
MiniExcel.SaveAsByTemplate(path, templatePath, value, config)
Excel 欄位名稱/索引/忽略屬性 
#### 1. 指定欄位名稱、欄位索引、欄位忽略
Excel 範例
程式碼csharp
public class ExcelAttributeDemo
{
    [ExcelColumnName("Column1")]
    public string Test1 { get; set; }
    [ExcelColumnName("Column2")]
    public string Test2 { get; set; }
    [ExcelIgnore]
    public string Test3 { get; set; }
    [ExcelColumnIndex("I")] // system will convert "I" to 8 index
    public string Test4 { get; set; }
    public string Test5 { get; } //wihout set will ignore
    public string Test6 { get; private set; } //un-public set will ignore
    [ExcelColumnIndex(3)] // start with 0
    public string Test7 { get; set; }
}
var rows = MiniExcel.Query(path).ToList();
Assert.Equal("Column1", rows[0].Test1);
Assert.Equal("Column2", rows[0].Test2);
Assert.Null(rows[0].Test3);
Assert.Equal("Test7", rows[0].Test4);
Assert.Null(rows[0].Test5);
Assert.Null(rows[0].Test6);
Assert.Equal("Test4", rows[0].Test7);
#### 2. 自訂格式（ExcelFormatAttribute）自 V0.21.0 起支援包含 ToString(string content) 方法格式的類別
類別
csharp
public class Dto
{
    public string Name { get; set; }
    [ExcelFormat("MMMM dd, yyyy")]
    public DateTime InDate { get; set; }
}
程式碼csharp
var value = new Dto[] {
    new Issue241Dto{ Name="Jack",InDate=new DateTime(2021,01,04)},
    new Issue241Dto{ Name="Henry",InDate=new DateTime(2020,04,05)},
};
MiniExcel.SaveAs(path, value);
結果
查詢支援自訂格式轉換
#### 3. 設定欄寬（ExcelColumnWidthAttribute）csharp
public class Dto
{
    [ExcelColumnWidth(20)]
    public int ID { get; set; }
    [ExcelColumnWidth(15.50)]
    public string Name { get; set; }
}
#### 4. 多個欄位名稱對應到同一個屬性。csharp
public class Dto
{
    [ExcelColumnName(excelColumnName:"EmployeeNo",aliases:new[] { "EmpNo","No" })]
    public string Empno { get; set; }
    public string Name { get; set; }
}
#### 5. System.ComponentModel.DisplayNameAttribute = ExcelColumnName.excelColumnNameAttribute
自 1.24.0 版本起，系統支援 System.ComponentModel.DisplayNameAttribute = ExcelColumnName.excelColumnNameAttributeC#
public class TestIssueI4TXGTDto
{
    public int ID { get; set; }
    public string Name { get; set; }
    [DisplayName("Specification")]
    public string Spc { get; set; }
    [DisplayName("Unit Price")]
    public decimal Up { get; set; }
}
#### 6. ExcelColumnAttribute自 V1.26.0 版本起，多個屬性可以簡化如下：
csharp
        public class TestIssueI4ZYUUDto
        {
            [ExcelColumn(Name = "ID",Index =0)]
            public string MyProperty { get; set; }
            [ExcelColumn(Name = "CreateDate", Index = 1,Format ="yyyy-MM",Width =100)]
            public DateTime MyProperty2 { get; set; }
        }
#### 7. DynamicColumnAttribute
自從 V1.26.0 起，我們可以動態設定 Column 的屬性
csharp
            var config = new OpenXmlConfiguration
            {
                DynamicColumns = new DynamicExcelColumn[] {
                    new DynamicExcelColumn("id"){Ignore=true},
                    new DynamicExcelColumn("name"){Index=1,Width=10},
                    new DynamicExcelColumn("createdate"){Index=0,Format="yyyy-MM-dd",Width=15},
                    new DynamicExcelColumn("point"){Index=2,Name="Account Point"},
                }
            };
            var path = PathHelper.GetTempPath();
            var value = new[] { new { id = 1, name = "Jack", createdate = new DateTime(2022, 04, 12) ,point = 123.456} };
            MiniExcel.SaveAs(path, value, configuration: config);
#### 8. 動態工作表屬性自從 V1.31.4 版本開始，我們可以動態設定工作表的屬性。我們可以設定工作表名稱和狀態（可見性）。csharp
            var configuration = new OpenXmlConfiguration
            {
                DynamicSheets = new DynamicExcelSheet[] {
                    new DynamicExcelSheet("usersSheet") { Name = "Users", State = SheetState.Visible },
                    new DynamicExcelSheet("departmentSheet") { Name = "Departments", State = SheetState.Hidden }
                }
            };
            var users = new[] { new { Name = "Jack", Age = 25 }, new { Name = "Mike", Age = 44 } };
            var department = new[] { new { ID = "01", Name = "HR" }, new { ID = "02", Name = "IT" } };
            var sheets = new Dictionary
            {
                ["usersSheet"] = users,
                ["departmentSheet"] = department
            };
            var path = PathHelper.GetTempPath();
            MiniExcel.SaveAs(path, sheets, configuration: configuration);
我們也可以使用新的屬性 ExcelSheetAttribute：C#
   [ExcelSheet(Name = "Departments", State = SheetState.Hidden)]
   private class DepartmentDto
   {
      [ExcelColumn(Name = "ID",Index = 0)]
      public string ID { get; set; }
      [ExcelColumn(Name = "Name",Index = 1)]
      public string Name { get; set; }
   }
### 新增、刪除、更新
#### 新增
v1.28.0 支援在最後一行後插入 N 行 CSV 資料csharp
// Origin
{
    var value = new[] {
          new { ID=1,Name ="Jack",InDate=new DateTime(2021,01,03)},
          new { ID=2,Name ="Henry",InDate=new DateTime(2020,05,03)},
    };
    MiniExcel.SaveAs(path, value);
}
// Insert 1 rows after last
{
    var value = new { ID=3,Name = "Mike", InDate = new DateTime(2021, 04, 23) };
    MiniExcel.Insert(path, value);
}
// Insert N rows after last
{
    var value = new[] {
          new { ID=4,Name ="Frank",InDate=new DateTime(2021,06,07)},
          new { ID=5,Name ="Gloria",InDate=new DateTime(2022,05,03)},
    };
    MiniExcel.Insert(path, value);
}
v1.37.0 支援在現有工作簿中插入新的工作表csharp
// Origin excel
{
    var value = new[] {
          new { ID=1,Name ="Jack",InDate=new DateTime(2021,01,03)},
          new { ID=2,Name ="Henry",InDate=new DateTime(2020,05,03)},
    };
    MiniExcel.SaveAs(path, value, sheetName: "Sheet1");
}
// Insert a new sheet
{
    var value = new { ID=3,Name = "Mike", InDate = new DateTime(2021, 04, 23) };
    MiniExcel.Insert(path, table, sheetName: "Sheet2");
}
#### 刪除(等待中)
#### 更新(等待中)
Excel 類型自動檢查 
MiniExcel 會根據 檔案副檔名 自動判斷是 xlsx 或 csv，但這種方式可能不準確，請手動指定。

Stream 無法判斷來源為哪種 excel，請手動指定。
csharp
stream.SaveAs(excelType:ExcelType.CSV);
//or
stream.SaveAs(excelType:ExcelType.XLSX);
//or
stream.Query(excelType:ExcelType.CSV);
//or
stream.Query(excelType:ExcelType.XLSX);
CSV
#### 注意預設回傳為 string 類型，且數值不會自動轉換為數字或日期時間，除非透過強型別泛型定義類型。
#### 自訂分隔符預設分隔符為 ,，你可以修改 Seperator 屬性來自訂分隔符
csharp
var config = new MiniExcelLibs.Csv.CsvConfiguration()
{
    Seperator=';'
};
MiniExcel.SaveAs(path, values,configuration: config);
自 V1.30.1 起支援自訂分隔符功能（感謝 @hyzx86）csharp
var config = new CsvConfiguration()
{
    SplitFn = (row) => Regex.Split(row, $"\"" target="_blank" rel="noopener noreferrer">\t,$)")
        .Select(s => Regex.Replace(s.Replace("\"\"", "\""), "^\"|\"$", "")).ToArray()
};
var rows = MiniExcel.Query(path, configuration: config).ToList();
#### 自訂換行符預設為 \r\n 作為換行字元，您可以修改 NewLine 屬性來自訂
csharp
var config = new MiniExcelLibs.Csv.CsvConfiguration()
{
    NewLine='\n'
};
MiniExcel.SaveAs(path, values,configuration: config);
#### 自訂編碼
預設編碼為「從位元組順序標記偵測編碼」（detectEncodingFromByteOrderMarks: true）
如果您有自訂編碼需求，請修改 StreamReaderFunc / StreamWriterFunc 屬性
csharp
// Read
var config = new MiniExcelLibs.Csv.CsvConfiguration()
{
    StreamReaderFunc = (stream) => new StreamReader(stream,Encoding.GetEncoding("gb2312"))
};
var rows = MiniExcel.Query(path, true,excelType:ExcelType.CSV,configuration: config);
// Write
var config = new MiniExcelLibs.Csv.CsvConfiguration()
{
    StreamWriterFunc = (stream) => new StreamWriter(stream, Encoding.GetEncoding("gb2312"))
};
MiniExcel.SaveAs(path, value,excelType:ExcelType.CSV, configuration: config);
#### 將空字串讀取為 null
預設情況下，空值會對應為 string.Empty。你可以修改這個行為csharp
var config = new MiniExcelLibs.Csv.CsvConfiguration()
{
   ReadEmptyStringAsNull = true
};
### DataReader
#### 1. GetReader
自 1.23.0 起，您可以使用 GetDataReader
csharp
    using (var reader = MiniExcel.GetReader(path,true))
    {
        while (reader.Read())
        {
            for (int i = 0; i < reader.FieldCount; i++)
            {
                var value = reader.GetValue(i);
            }
        }
    }
 非同步
v0.17.0 支援非同步（感謝 isdaniel ( SHIH,BING-SIOU)](https://github.com/isdaniel))
csharp
public static Task SaveAsAsync(string path, object value, bool printHeader = true, string sheetName = "Sheet1", ExcelType excelType = ExcelType.UNKNOWN, IConfiguration configuration = null)
public static Task SaveAsAsync(this Stream stream, object value, bool printHeader = true, string sheetName = "Sheet1", ExcelType excelType = ExcelType.XLSX, IConfiguration configuration = null)
public static Task> QueryAsync(string path, bool useHeaderRow = false, string sheetName = null, ExcelType excelType = ExcelType.UNKNOWN, string startCell = "A1", IConfiguration configuration = null)
public static Task> QueryAsync(this Stream stream, string sheetName = null, ExcelType excelType = ExcelType.UNKNOWN, string startCell = "A1", IConfiguration configuration = null) where T : class, new()
public static Task> QueryAsync(string path, string sheetName = null, ExcelType excelType = ExcelType.UNKNOWN, string startCell = "A1", IConfiguration configuration = null) where T : class, new()
public static Task>> QueryAsync(this Stream stream, bool useHeaderRow = false, string sheetName = null, ExcelType excelType = ExcelType.UNKNOWN, string startCell = "A1", IConfiguration configuration = null)
public static Task SaveAsByTemplateAsync(this Stream stream, string templatePath, object value)
public static Task SaveAsByTemplateAsync(this Stream stream, byte[] templateBytes, object value)
public static Task SaveAsByTemplateAsync(string path, string templatePath, object value)
public static Task SaveAsByTemplateAsync(string path, byte[] templateBytes, object value)
public static Task QueryAsDataTableAsync(string path, bool useHeaderRow = true, string sheetName = null, ExcelType excelType = ExcelType.UNKNOWN, string startCell = "A1", IConfiguration configuration = null)
-  v1.25.0 支援 cancellationToken。
其他
#### 1. 列舉型別
請確保 excel 與屬性名稱相同，系統會自動對應（不區分大小寫）
自 V0.18.0 起支援列舉型別描述（Enum Description）csharp
public class Dto
{
    public string Name { get; set; }
    public I49RYZUserType UserType { get; set; }
}
public enum Type
{
    [Description("General User")]
    V1,
    [Description("General Administrator")]
    V2,
    [Description("Super Administrator")]
    V3
}
自 1.30.0 版本起支援將 Excel Description 轉換為 Enum，感謝 @KaneLeung
#### 2. 將 CSV 轉換為 XLSX 或將 XLSX 轉換為 CSVcsharp
MiniExcel.ConvertXlsxToCsv(xlsxPath, csvPath);
MiniExcel.ConvertXlsxToCsv(xlsxStream, csvStream);
MiniExcel.ConvertCsvToXlsx(csvPath, xlsxPath);
MiniExcel.ConvertCsvToXlsx(csvStream, xlsxStream);
`csharp
using (var excelStream = new FileStream(path: filePath, FileMode.Open, FileAccess.Read))
using (var csvStream = new MemoryStream())
{
   MiniExcel.ConvertXlsxToCsv(excelStream, csvStream);
}
#### 3. 自訂 CultureInfo

自從 1.22.0 版本起，您可以像下面這樣自訂 CultureInfo，系統預設為 CultureInfo.InvariantCulture。

var config = new CsvConfiguration()
{
    Culture = new CultureInfo("fr-FR"),
};
MiniExcel.SaveAs(path, value, configuration: config);// or
MiniExcel.Query(path, configuration: config);


#### 4. 自訂緩衝區大小
    public abstract class Configuration : IConfiguration
    {
        public int BufferSize { get; set; } = 1024 * 512;
    }
#### 5. 快速模式
系統不會控制記憶體，但你可以獲得更快的儲存速度。
var config = new OpenXmlConfiguration() { FastMode = true };
MiniExcel.SaveAs(path, reader,configuration:config);
#### 6. 批次新增圖片 (MiniExcel.AddPicture)
請在批次產生資料列之前新增圖片，否則在呼叫 AddPicture 時系統將會佔用大量記憶體。
var images = new[]
{
    new MiniExcelPicture
    {
        ImageBytes = File.ReadAllBytes(PathHelper.GetFile("images/github_logo.png")),
        SheetName = null, // default null is first sheet
        CellAddress = "C3", // required
    },
    new MiniExcelPicture
    {
        ImageBytes = File.ReadAllBytes(PathHelper.GetFile("images/google_logo.png")),
        PictureType = "image/png", // default PictureType = image/png
        SheetName = "Demo",
        CellAddress = "C9", // required
        WidthPx = 100,
        HeightPx = 100,
    },
};
MiniExcel.AddPicture(path, images);
#### 7. 取得工作表尺寸
var dim = MiniExcel.GetSheetDimensions(path);
範例：

#### 1. SQLite & Dapper 大檔案 SQL 插入避免 OOM

注意：請不要在 Query 之後呼叫 ToList/ToArray 方法，這會將所有資料載入記憶體

using (var connection = new SQLiteConnection(connectionString))
{
    connection.Open();
    using (var transaction = connection.BeginTransaction())
    using (var stream = File.OpenRead(path))
    {
       var rows = stream.Query();
       foreach (var row in rows)
             connection.Execute("insert into T (A,B) values (@A,@B)", new { row.A, row.B }, transaction: transaction);
       transaction.Commit();
    }
}


效能表現：
#### 2. ASP.NET Core 3.1 或 MVC 5 下載/上傳 Excel Xlsx API 範例 試用
public class ApiController : Controller
{
    public IActionResult Index()
    {
        return new ContentResult
        {
            ContentType = "text/html",
            StatusCode = (int)HttpStatusCode.OK,
            Content = @"
DownloadExcel

DownloadExcelFromTemplatePath

DownloadExcelFromTemplateBytes

Upload Excel

     

    

    public IActionResult DownloadExcel()
    {
        var values = new[] {
            new { Column1 = "MiniExcel", Column2 = 1 },
            new { Column1 = "Github", Column2 = 2}
        };
        var memoryStream = new MemoryStream();
        memoryStream.SaveAs(values);
        memoryStream.Seek(0, SeekOrigin.Begin);
        return new FileStreamResult(memoryStream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
        {
            FileDownloadName = "demo.xlsx"
        };
    }
    public IActionResult DownloadExcelFromTemplatePath()
    {
        string templatePath = "TestTemplateComplex.xlsx";
        Dictionary value = new Dictionary()
        {
            ["title"] = "FooCompany",
            ["managers"] = new[] {
                new {name="Jack",department="HR"},
                new {name="Loan",department="IT"}
            },
            ["employees"] = new[] {
                new {name="Wade",department="HR"},
                new {name="Felix",department="HR"},
                new {name="Eric",department="IT"},
                new {name="Keaton",department="IT"}
            }
        };
        MemoryStream memoryStream = new MemoryStream();
        memoryStream.SaveAsByTemplate(templatePath, value);
        memoryStream.Seek(0, SeekOrigin.Begin);
        return new FileStreamResult(memoryStream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
        {
            FileDownloadName = "demo.xlsx"
        };
    }
    private static Dictionary TemplateBytesCache = new Dictionary();
    static ApiController()
    {
        string templatePath = "TestTemplateComplex.xlsx";
        byte[] bytes = System.IO.File.ReadAllBytes(templatePath);
        TemplateBytesCache.Add(templatePath, bytes);
    }
    public IActionResult DownloadExcelFromTemplateBytes()
    {
        byte[] bytes = TemplateBytesCache["TestTemplateComplex.xlsx"];
        Dictionary value = new Dictionary()
        {
            ["title"] = "FooCompany",
            ["managers"] = new[] {
                new {name="Jack",department="HR"},
                new {name="Loan",department="IT"}
            },
            ["employees"] = new[] {
                new {name="Wade",department="HR"},
                new {name="Felix",department="HR"},
                new {name="Eric",department="IT"},
                new {name="Keaton",department="IT"}
            }
        };
        MemoryStream memoryStream = new MemoryStream();
        memoryStream.SaveAsByTemplate(bytes, value);
        memoryStream.Seek(0, SeekOrigin.Begin);
        return new FileStreamResult(memoryStream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
        {
            FileDownloadName = "demo.xlsx"
        };
    }
    public IActionResult UploadExcel(IFormFile excel)
    {
        var stream = new MemoryStream();
        excel.CopyTo(stream);
        foreach (var item in stream.Query(true))
        {
            // do your logic etc.
        }        return Ok("File uploaded successfully");
    }
}
####  3. 分頁查詢
void Main()
{
    var rows = MiniExcel.Query(path);
    Console.WriteLine("==== No.1 Page ====");
    Console.WriteLine(Page(rows,pageSize:3,page:1));
    Console.WriteLine("==== No.50 Page ====");
    Console.WriteLine(Page(rows,pageSize:3,page:50));
    Console.WriteLine("==== No.5000 Page ====");
    Console.WriteLine(Page(rows,pageSize:3,page:5000));
}public static IEnumerable Page(IEnumerable en, int pageSize, int page)
{
    return en.Skip(page * pageSize).Take(pageSize);
}
#### 4. WebForm 透過 Memorystream 匯出 Excel
var fileName = "Demo.xlsx";
var sheetName = "Sheet1";
HttpResponse response = HttpContext.Current.Response;
response.Clear();
response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
response.AddHeader("Content-Disposition", $"attachment;filename=\"{fileName}\"");
var values = new[] {
    new { Column1 = "MiniExcel", Column2 = 1 },
    new { Column1 = "Github", Column2 = 2}
};
var memoryStream = new MemoryStream();
memoryStream.SaveAs(values, sheetName: sheetName);
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.CopyTo(Response.OutputStream);
response.End();
#### 5. 動態 i18n 多語言與角色權限管理

如範例所示，建立一個方法來處理 i18n 和權限管理，並使用 yield return 返回 IEnumerable>，以實現動態且低記憶體的處理效果

void Main()
{
    var value = new Order[] {
        new Order(){OrderNo = "SO01",CustomerID="C001",ProductID="P001",Qty=100,Amt=500},
        new Order(){OrderNo = "SO02",CustomerID="C002",ProductID="P002",Qty=300,Amt=400},
    };
    Console.WriteLine("en-Us and Sales role");
    {
        var path = Path.GetTempPath() + Guid.NewGuid() + ".xlsx";
        var lang = "en-US";
        var role = "Sales";
        MiniExcel.SaveAs(path, GetOrders(lang, role, value));
        MiniExcel.Query(path, true).Dump();
    }
    Console.WriteLine("zh-CN and PMC role");
    {
        var path = Path.GetTempPath() + Guid.NewGuid() + ".xlsx";
        var lang = "zh-CN";
        var role = "PMC";
        MiniExcel.SaveAs(path, GetOrders(lang, role, value));
        MiniExcel.Query(path, true).Dump();
    }
}
private IEnumerable> GetOrders(string lang, string role, Order[] orders)
{
    foreach (var order in orders)
    {
        var newOrder = new Dictionary();
        if (lang == "zh-CN")
        {
            newOrder.Add("客户编号", order.CustomerID);
            newOrder.Add("订单编号", order.OrderNo);
            newOrder.Add("产品编号", order.ProductID);
            newOrder.Add("数量", order.Qty);
            if (role == "Sales")
                newOrder.Add("价格", order.Amt);
            yield return newOrder;
        }
        else if (lang == "en-US")
        {
            newOrder.Add("Customer ID", order.CustomerID);
            newOrder.Add("Order No", order.OrderNo);
            newOrder.Add("Product ID", order.ProductID);
            newOrder.Add("Quantity", order.Qty);
            if (role == "Sales")
                newOrder.Add("Amount", order.Amt);
            yield return newOrder;
        }
        else
        {
            throw new InvalidDataException($"lang {lang} wrong");
        }
    }
}public class Order
{
    public string OrderNo { get; set; }
    public string CustomerID { get; set; }
    public decimal Qty { get; set; }
    public string ProductID { get; set; }
    public decimal Amt { get; set; }
}


常見問答
#### Q: Excel 標題欄名稱與類別屬性名稱不一致時，如何對應？
A. 請使用 ExcelColumnName 屬性
#### Q. 如何查詢或匯出多個工作表？

A. 使用 GetSheetNames 方法，並搭配 Query 的 sheetName 參數。

var sheets = MiniExcel.GetSheetNames(path);
foreach (var sheet in sheets)
{
    Console.WriteLine($"sheet name : {sheet} ");
    var rows = MiniExcel.Query(path,useHeaderRow:true,sheetName:sheet);
    Console.WriteLine(rows);
}


#### 問：如何查詢或匯出有關工作表可見性的資訊？

答：使用 GetSheetInformations 方法。

var sheets = MiniExcel.GetSheetInformations(path);
foreach (var sheetInfo in sheets)
{
    Console.WriteLine($"sheet index : {sheetInfo.Index} "); // next sheet index - numbered from 0
    Console.WriteLine($"sheet name : {sheetInfo.Name} ");   // sheet name
    Console.WriteLine($"sheet state : {sheetInfo.State} "); // sheet visibility state - visible / hidden
}


#### Q. 使用 Count 會將所有資料載入記憶體嗎？
不會，影像測試有 1 百萬行*10 列的資料，最大記憶體用量小於 60MB，耗時 13.65 秒
#### Q. Query 如何使用整數索引？
Query 的預設索引是字串 Key: A,B,C.... 如果要改為數字索引，請建立以下方法進行轉換
void Main()
{
    var path = @"D:\git\MiniExcel\samples\xlsx\TestTypeMapping.xlsx";
    var rows = MiniExcel.Query(path,true);
    foreach (var r in ConvertToIntIndexRows(rows))
    {
        Console.Write($"column 0 : {r[0]} ,column 1 : {r[1]}");
        Console.WriteLine();
    }
}
private IEnumerable> ConvertToIntIndexRows(IEnumerable

MiniExcel

簡介

功能特色

2.0 版預覽

開始使用

安裝方式

發行說明

待辦事項

效能

Excel 查詢/匯入

建立/匯出 Excel

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