Copy text from WPF DataGrid to Clipboard to Excel

I have WPF DataGrid (VS2010 C#). I copied the data from DataGrid to Clipboard and write it to an Excel file. Below is my code.

data开发者_如何转开发Grid1.SelectAllCells();
dataGrid1.ClipboardCopyMode = DataGridClipboardCopyMode.IncludeHeader;
ApplicationCommands.Copy.Execute(null, dataGrid1);
dataGrid1.UnselectAllCells();
string path1 = "C:\\test.xls";
string result1 = (string)Clipboard.GetData(DataFormats.CommaSeparatedValue);
Clipboard.Clear();
System.IO.StreamWriter file1 = new System.IO.StreamWriter(path1);
file1.WriteLine(result1);
file1.Close();

Everything works out OK except when I open the excel file it gives me two warning:

"The file you are trying to open 'test.xls' is in a different format than specified by the file extension. Verify that the file is not corrupted and is from a trusted source before opening the file. Do you want to open the file now?"

"Excel has detected that 'test.xls' is a SYLK file, but cannot load it."

But after I click through it, it still open the excel file OK and data are formated as it supposed to be. But I can't find how to get rid of the two warnings before the excel file is open.

You need to use csv as extension. Xls is the Excel file extension. So

string path1 = "C:\\test.csv";

should work.

A problem like yours has already been described here : generating/opening CSV from console - file is in wrong format error. Does it helps to solve yours ?

Edit : Here is the Microsoft KB related => http://support.microsoft.com/kb/323626