如何在导出到 Excel 时将列表分配给 closedXML 中的单元格（下拉格式）

Question

我只是想导出一个 Datatable（Datatable 没有任何数据 - 只有 header）。此外，我有一个 List<String>，我想将其附加到该列，这样，在导出到 excel 之后，该列（除 header 之外的所有单元格）应该包含列表数据作为 Dropdown格式。

我用谷歌搜索了很多，但找不到任何解决方案。以下是我访问过但没有成功的链接。

Whosebug

Codeplex - ClosedXML

下面是我目前尝试过的方法。

    private void ExcelExport(DataTable dt, GridView Template)
    {
        bool isListRequired = false;
        List<string> groupCodeList = new List<string>(); ;
        Template.DataBind();
        if (Template.HeaderRow != null)
        {
            foreach (TableCell cell in Template.HeaderRow.Cells)
            {
                if (cell.Text == "ActivityGroup_Code")
                {
                    isListRequired = true;
                    groupCodeList = db.PMS_M_ActivityGroup.Select(a => a.ActivityGroup_Code).ToList();
                }
                    dt.Columns.Add(cell.Text);
            }

            var workbook = new XLWorkbook();
            var returnValue = workbook.AddWorksheet(dt);
            var worksheet = workbook.Worksheet(1);
            if (isListRequired)
            {
                //worksheet.Cell("E2").DataValidation.List(string.Join("",groupCodeList.ToArray()));
                //worksheet.Cell(2,5).InsertData(groupCodeList);

                // Trying to add a list to the Cell (E2) - and applying datavalidation to the Column (5th column - E Range)
                // Dropdown is created in excel(with blank) but data is not population to that dropdown
                worksheet.Cell(2, 5).InsertData(groupCodeList);
                worksheet.Column(5).SetDataValidation().List(string.Join("", groupCodeList.ToArray()));
            }

            Response.ClearContent();
            Response.Buffer = true;
            Response.AddHeader("content-disposition", "attachment; filename=ExcelFormat.xlsx");
            Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
            Response.Charset = "";
            using (MemoryStream MyMemoryStream = new MemoryStream())
            {
                workbook.SaveAs(MyMemoryStream);
                MyMemoryStream.WriteTo(Response.OutputStream);
                Response.Flush();
                Response.End();
            }
        }
    }

我调用这个方法的代码是

 List<PMS_M_ActivityGroup> activitygroup = new List<PMS_M_ActivityGroup>();
 activitygroup = db.PMS_M_ActivityGroup.Select(a => a).ToList();
 DataTable dt2 = new DataTable("Excel Template");
 GridView Template2 = new GridView();
 Template2.DataSource = activitygroup;
 ExcelExport(dt2, Template2);

请求您提供如何实现所需功能的解决方案。

谢谢

Answer 1

我得到了解决方案。它并没有那么简单，但我们需要做一些技巧来实现这个功能。在此处发布 - 可能对专门使用 ClosedXML 库的其他开发人员有所帮助。

所以我们需要做的是：我们需要创建一个单独的（第二个）sheet，申请 DataValidation 到要显示下拉列表的第 sheet 列。

private void ExcelExportValidation(DataTable dt, GridView Template)
{
    try
    {
        bool isListRequired = false;
        List<string> groupCodeList = new List<string>(); ;
        Template.DataBind();
        if (Template.HeaderRow != null)
        {
           foreach (TableCell cell in Template.HeaderRow.Cells)
           {
               if (cell.Text == "ActivityGroup_Code")
               {
                   isListRequired = true;
                   groupCodeList = db.PMS_M_ActivityGroup.Select(a => a.ActivityGroup_Code).ToList();
               }
               dt.Columns.Add(cell.Text);
           }

           var workbook = new XLWorkbook();
           var returnValue = workbook.AddWorksheet(dt);
           var worksheet = workbook.Worksheet(1);
           if (isListRequired)
           {
               var tempDt = Helper.ConvertListToDataTable(groupCodeList);
               tempDt.TableName = "Sheet1";
               var returnValue2 = workbook.AddWorksheet(tempDt);
               var worksheet2 = workbook.Worksheet(2);
               int lastCellNo = groupCodeList.Count + 1;                       
                     worksheet.Column(5).SetDataValidation().List(worksheet2.Range("A2:A" + lastCellNo), true);                                               
            }
            Response.ClearContent();
            Response.Buffer = true;
            Response.AddHeader("content-disposition", "attachment; filename=ExcelFormat.xlsx");
            Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
            Response.Charset = "";
            using (MemoryStream MyMemoryStream = new MemoryStream())
            {
                workbook.SaveAs(MyMemoryStream);
                MyMemoryStream.WriteTo(Response.OutputStream);
                Response.Flush();
                Response.End();
            }
        }
    }
    catch (Exception ex)
    {
        ExceptionLogging.SendErrorToText(ex);
    }
}

Answer 2

@Chandan 确实给出了正确的答案。我发布了一个独立的解决方案代码片段，它将 excel 文件保存在磁盘上：

var workbook = new XLWorkbook();

DataTable userData = new DataTable("Sheet1");
userData.Columns.Add("Master Column");
workbook.AddWorksheet(userData);
var worksheet = workbook.Worksheet(1);

DataTable validationTable = new DataTable();
validationTable.Columns.Add("DropDownItems");
validationTable.TableName = "Sheet2";

DataRow dr = validationTable.NewRow();
dr["DropDownItems"] = "Item1";
validationTable.Rows.Add(dr);

dr = validationTable.NewRow();
dr["DropDownItems"] = "Item2";
validationTable.Rows.Add(dr);

dr = validationTable.NewRow();
dr["DropDownItems"] = "Item3";
validationTable.Rows.Add(dr);

var worksheet2 = workbook.AddWorksheet(validationTable);
worksheet.Column(1).SetDataValidation().List(worksheet2.Range("A2:A4"), true);

//optional: you can hide the data validation sheet from your users if you want
//worksheet2.Hide();

workbook.SaveAs(@"C:\myworkbook.xlsx");

它在 Sheet1 中创建下拉列表，如下所示：

如何在导出到 Excel 时将列表分配给 closedXML 中的单元格（下拉格式）

How to assign a list to a Cell(Dropdown format) in closedXML while Exporting to Excel

c#

excel

asp.net-mvc-5

export-to-excel

closedxml