C#使用MiniExcel導入導出數據到Excel/CSV文件

MiniExcel簡介

簡單、高效避免OOM的.NET處理Excel查、寫、填充數據工具。

目前主流框架大多需要將數據全載入到記憶體方便操作，但這會導致記憶體消耗問題，MiniExcel 嘗試以 Stream 角度寫底層演算法邏輯，能讓原本1000多MB占用降低到幾MB，避免記憶體不夠情況。

特點：

• 低記憶體耗用，避免OOM、頻繁 Full GC 情況
• 支持即時操作每行數據
• 兼具搭配 LINQ 延遲查詢特性，能辦到低消耗、快速分頁等複雜查詢
• 輕量，不需要安裝 Microsoft Office、COM+，DLL小於150KB
• 簡便操作的 API 風格

項目地址：mini-software/MiniExcel: Fast, Low-Memory, Easy Excel .NET helper to import/export/template spreadsheet (support Linux, Mac) (github.com)

安裝 MiniExcel

導出數據

 public class Student
  {
      public string? Name { get; set; }
      public string? Home { get; set; }
      public int? Age {  get; set; }   
  }

 //獲得當前目錄的路徑
 string currentDirectory = Directory.GetCurrentDirectory();

 //合併當前目錄與Excel文件名
 var path = Path.Combine(currentDirectory, $"{Guid.NewGuid()}.xlsx");
 
  List<Student> studentList = new List<Student>()
  {
      new Student { Name = "小東", Home = "New York", Age = 25 },
      new Student { Name = "小西", Home = "London", Age = 22 },
      new Student { Name = "小南", Home = "Paris", Age = 28 },
      new Student { Name = "小北", Home = "Tokyo", Age = 24 },
      new Student { Name = "小王", Home = "Berlin", Age = 26 }
 };

MiniExcel.SaveAs(path, studentList);

導入Excel中如下圖所示：

但是目前還不支持Excel的插入：

因此如果遇到不僅僅只是生成Excel，後續還要向Excel添加數據的需求，可以用csv代替：

 //獲得當前目錄的路徑
 string currentDirectory = Directory.GetCurrentDirectory();

 //合併當前目錄與CSV文件名
 var path = Path.Combine(currentDirectory, $"{Guid.NewGuid()}.csv");

 List<Student> studentList = new List<Student>()
  {
      new Student { Name = "小東", Home = "New York", Age = 25 },
      new Student { Name = "小西", Home = "London", Age = 22 },
      new Student { Name = "小南", Home = "Paris", Age = 28 },
      new Student { Name = "小北", Home = "Tokyo", Age = 24 },
      new Student { Name = "小王", Home = "Berlin", Age = 26 }
 };

 MiniExcel.SaveAs(path, studentList);

生成的CSV文件如下圖所示：

向CSV文件繼續添加數據：

  //獲得當前目錄的路徑
  string currentDirectory = Directory.GetCurrentDirectory();

  //合併當前目錄與Excel文件名
  //var path = Path.Combine(currentDirectory, $"{Guid.NewGuid()}.csv");
  var path = Path.Combine(currentDirectory, "10de09bb-ad8c-4430-b717-5f24117a11a6.csv");

  List<Student> studentList = new List<Student>()
   {
       new Student { Name = "小東", Home = "New York", Age = 25 },
       new Student { Name = "小西", Home = "London", Age = 22 },
       new Student { Name = "小南", Home = "Paris", Age = 28 },
       new Student { Name = "小北", Home = "Tokyo", Age = 24 },
       new Student { Name = "小王", Home = "Berlin", Age = 26 }
  };

  //MiniExcel.SaveAs(path, studentList);
  MiniExcel.Insert(path, studentList);

繼續添加數據後的CSV文件如下圖所示：

導入數據

 var path = "你的文件路徑";
 var rows = MiniExcel.Query<Student>(path);

實現效果如下所示：