//---------------------------------------------------
//
// Internal Methods
//
//---------------------------------------------------
#region Internal Methods
/// <summary>
/// Performs the actual call to display a file open dialog.
/// </summary>
/// <exception cref="InvalidOperationException">
/// Thrown if there is an invalid filename, if
/// a subclass failure occurs or if the buffer length
/// allocated to store the filenames occurs.
/// </exception>
/// <remarks>
/// The call chain is ShowDialog > RunDialog >
/// RunFileDialog (this function). In
/// FileDialog.RunDialog, we created the OPENFILENAME
/// structure - so all this function needs to do is
/// call GetOpenFileName and process the result code.
/// </remarks>
internal override bool RunFileDialog(NativeMethods.OPENFILENAME_I ofn)
{
bool result = false;
// Make the actual call to GetOpenFileName. This function
// blocks on GetOpenFileName until the entire dialog display
// is completed - any interaction we have with the dialog
// while it's open takes place through our HookProc. The
// return value is a bool; true = success.
result = UnsafeNativeMethods.GetOpenFileName(ofn);
if (!result) // result was 0 (false), so an error occurred.
{
// Something may have gone wrong - check for error conditions
// by calling CommDlgExtendedError to get the specific error.
int errorCode = UnsafeNativeMethods.CommDlgExtendedError();
// Throw an appropriate exception if we know what happened:
switch (errorCode)
{
// FNERR_INVALIDFILENAME is usually triggered when an invalid initial filename is specified
case NativeMethods.FNERR_INVALIDFILENAME:
throw new InvalidOperationException(SR.Get(SRID.FileDialogInvalidFileName, SafeFileName));
case NativeMethods.FNERR_SUBCLASSFAILURE:
throw new InvalidOperationException(SR.Get(SRID.FileDialogSubClassFailure));
// note for FNERR_BUFFERTOOSMALL:
// This error likely indicates a problem with our buffer size growing code;
// take a look at that part of HookProc if customers report this error message is occurring.
case NativeMethods.FNERR_BUFFERTOOSMALL:
throw new InvalidOperationException(SR.Get(SRID.FileDialogBufferTooSmall));
/*
* According to MSDN, the following errors can also occur, but we do not handle them as
* they are very unlikely, and if they do occur, they indicate a catastrophic failure.
* Most are related to features we do not wrap in our implementation.
*
* CDERR_DIALOGFAILURE
* CDERR_FINDRESFAILURE
* CDERR_NOHINSTANCE
* CDERR_INITIALIZATION
* CDERR_NOHOOK
* CDERR_LOCKRESFAILURE
* CDERR_NOTEMPLATE
* CDERR_LOADRESFAILURE
* CDERR_STRUCTSIZE
* CDERR_LOADSTRFAILURE
* CDERR_MEMALLOCFAILURE
* CDERR_MEMLOCKFAILURE
*/
}
}
return(result);
}
internal override bool RunFileDialog(NativeMethods.OPENFILENAME_I ofn)
{
bool openFileName = UnsafeNativeMethods.GetOpenFileName(ofn);
if (!openFileName)
{
switch (UnsafeNativeMethods.CommDlgExtendedError())
{
case 12289:
throw new InvalidOperationException(SR.Get("FileDialogSubClassFailure"));
case 12290:
throw new InvalidOperationException(SR.Get("FileDialogInvalidFileName", new object[]
{
base.SafeFileName
}));
case 12291:
throw new InvalidOperationException(SR.Get("FileDialogBufferTooSmall"));
}
}
return(openFileName);
}