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

问题:

I am just trying to Export a Datatable (Datatable doesn't have any data - having only header). In addition, i have a List<String> which i want to append to the column, such that, after export to excel that column (all cells except header) should contain list data as Dropdown format.

I have googled a lot and couldn't able to find any solutions. Below are the links which i have visited but no luck.

StackOverflow

Codeplex - ClosedXML

And below are the one what i have tried so far.

    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();             }         }     } 

And the code where i am calling this method is

 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); 

Request you to provide me the solution how to achieve the required functionality.

Thank you

回答1:

I got the solution. It's not that much simple but we need to do some tricky to achieve this functionality. Posting here - might be helpful for other developers who are using specifically ClosedXML library.

So what we need to do is : we need to create a separate(Second) sheet, apply datavalidation to the 1st sheet column where dropdown to be appeared.

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);     } } 

回答2:

@Chandan has certainly given the right lead to the answer. I'm posting a stand-alone solution code snippet which saves the excel file on disk:

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"); 

It creates drop down in Sheet1 as shown below:

文章来源: How to assign a list to a Cell(Dropdown format) in closedXML while Exporting to Excel