epplus使用匿名类型的LoadFromCollection

本文关键字：类型 LoadFromCollection epplus | 更新日期: 2023-09-27 18:11:05

我有一个包含匿名类型集合的IEnumerable<object>数据源。匿名类型的实际结构在设计时是不知道的，所以我试图找到一个通用的解决方案，可以处理任何匿名类型。

如何将它们加载到epplus中以创建电子表格?我有一个名为ws的工作表，我尝试:

ws.Cells["A1"].LoadFromCollection(dataSource, true);

然而，当它运行时，它将所有匿名类型的属性输出到单个单元格中:

{ Id = 10000, Title = This is a test }

我已经尝试通过在MemberInfo使用:

var members = dataSource.First().GetType().GetMembers();
ws.Cells["A1"].LoadFromCollection(this._dataSource, true,
    TableStyles.Medium1, BindingFlags.Public, members);

但是这会抛出一个异常:

参数properties中提供的属性必须与T

具有相同的类型
关于如何在c#中使用匿名类型创建电子表格，有什么建议吗?

epplus使用匿名类型的LoadFromCollection

我已经测试过了

using (var excel = new OfficeOpenXml.ExcelPackage())
{
    var sheet = excel.Workbook.Worksheets.Add("Test");
    sheet.Cells["A1"].LoadFromCollection(dataSource, true);
    excel.SaveAs(new FileInfo(@"C:'Temp'Test.xlsx"));
}

使用以下示例数据:

var dataSource = Enumerable.Range(1, 100).Select(i => new{ ID=i, Title="Title " + i });

很好。它创建具有正确标题和100行的两列。

但是，只有在编译时知道结构时才应该使用匿名类型。

你可以用DataTable和LoadFromDataTable代替。由于我不知道如何创建匿名类型，所以我只展示一个小示例:

DataTable dataSource = new DataTable();
dataSource.Columns.Add("Id");    // default type is string 
dataSource.Columns.Add("Title");  
// add other columns
dataSource.Rows.Add("1", "Title1");
// add other rows
using (var excel = new OfficeOpenXml.ExcelPackage())
{
    var sheet = excel.Workbook.Worksheets.Add("Test");
    sheet.Cells["A1"].LoadFromDataTable(dataSource, true);
    excel.SaveAs(new FileInfo(@"C:'Temp'Test.xlsx"));
}

可以对匿名类型进行分组，以便更容易地导出数据表。"在参数properties中提供的属性必须与T具有相同类型"的错误仍然存在，解决方法是使用数据表。

// Imagine list is your main datasource
IEnumerable<object> list = Enumerable.Empty<object>(); // Data Source of <object>
// Added anon types at runtime added to the object list
var anonTypesOne = new object[] 
{ 
    new { GuidID = Guid.NewGuid(), StringProperty = "the string property" },
    new { IntegerID = 1, IntegerProperty = 99 }
};
var anonTypesTwo = new object[]
{
    new { StringID = "1", BooleanProperty = true, NumberProperty = 3, StringProperty = "Four" },
    new { GuidID = Guid.NewGuid(), NumberThree = 3 },
    new { GuidID = Guid.NewGuid(), NumberThree = 3 },
    new { GuidID = Guid.NewGuid(), NumberThree = 3 }
};
list = list.Concat(anonTypesOne).Concat(anonTypesTwo);
// Grouping works on anon types so we can group the export into their own tables
var groupings = list.GroupBy(i => i.GetType());
using(var package = new ExcelPackage(new FileInfo("C:''Temp''Anon.xlsx")))
{
    var ws = package.Workbook.Worksheets.Add("Anonymous Types");
    // add each "anon type matched grouping"
    foreach(var grouping in groupings)
    {
        var isNew = ws.Dimension == null; // the sheet is empty if Dimension is null.
        var row = 0;
        if(isNew)
        {
            row = 1; // start from the first row
        }
        else 
        {       
            // otherwise there are tables already, start from the bottom
            row = ws.Dimension.End.Row; 
        }       
        // because of EPP inheritance bug of T, we can just use dataTable
        DataTable dt = new DataTable(grouping.Key.Name);
        var properties = grouping.Key.GetProperties(); // Get anon type Properties
        foreach(var property in properties)
        {
            dt.Columns.Add(property.Name);
        }
        foreach(var item in grouping.ToList())
        {
            var dataRow = dt.NewRow();
            foreach(var p in properties) // populate a single row
            {
                dataRow[p.Name] = p.GetValue(item); // item is anon object instance
            }
            dt.Rows.Add(dataRow);
        }
        if(isNew) // load into the top most left cell of the worksheet
            ws.Cells[1, 1].LoadFromDataTable(dt, PrintHeaders: true);
        else // load from the dimension of current items + 1 row for spacing
            ws.Cells[ws.Dimension.End.Row + 1, 1].LoadFromDataTable(dt, PrintHeaders: true);
        ws.InsertRow(ws.Dimension.End.Row + 2, 5); // Insert some padding between each group
    }
    package.Save();
}

我是，这个线程是旧的，但我正在寻找同样的问题。用下面的代码(VB)我已经成功。Carsten 

    Dim targetFile = New IO.FileInfo(sFN)
    Dim dataSource = Enumerable.Range(0, 1).Select(Function(i) New With {.ID = 1000, .Titel = "This is a test "}).ToList
    Using epp = New OfficeOpenXml.ExcelPackage(targetFile)
        Dim ws = epp.Workbook.Worksheets.Add("lst_Anonymous")
        ws.Cells(1, 1).LoadFromCollection(dataSource, True,
                                               OfficeOpenXml.Table.TableStyles.Medium1,
                                               Reflection.BindingFlags.Public,
                                               dataSource.GetType.GetGenericArguments()(0).GetProperties)
                    epp.Save()
    End Using
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