Asp. NET export Excel prompt when opening: Specify file inconsistencies with file name extensions _ Practical Tips

"Export data from the GridView in the page to Excel table" encountered an error: C # export Excel file open Excel file format inconsistent with extension specified format. Specific hints as shown:

workaround : Use the "Modify registry" method to resolve this problem, which does not solve the root problem:

1, open Registry Editor method: Start-> run-> input regedit-> OK
2, find the registry subkey hkey_current_user\software\microsoft\office\12.0\excel\security
3, in the right margin, click the right mouse button, select "New-> DWORD Value (D)", enter "extensionhardening" click OK.
4, with the right mouse click Extensionhardening, and then click "Modify (M)", in the numerical data to fill in "0" can be determined.
5, close the Registry Editor, open the XLS again to see if the hint is not gone?

data settings for the value set by Extensionhardening :
* 0: Do not check the file name extension and file type and bypass the function's warning message.
* 1: Check file name extension and file type. If they do not match, a warning message is displayed.
* 2: Check file name extension and file type. Do not open the file if they do not match