WPF SaveFileDialog DefaultExt ignored?

Question

var dlg = new SaveFileDialog();
dlg.FileName = "graph";
dlg.DefaultExt = ".bmp";
dlg.Filter = "PNG|*.png|DOT|*.dot|Windows Bitmap Format|*.bmp|GIF|*.gif|JPEG|*.jpg|PDF|*.pdf|Scalable Vector Graphics|*.svg|Tag Image File Format|*.tiff";

The extension always defaults to .png. It seems the DefaultExt is ignored if there is a Filter; then it just defaults to the first option in the list.

Is there a way to force it to actually respect the default ext?

Answer 1

I'm a few years too late, but coincidentally, I found a solution to the problem while looking at the code from this question.

There he specified the extension without a .. I then looked into the microsoft documentation. In the example the DefaultExt was also specified without a ..

If DefaultExt is specified with a ., FileDialog will automatically choose the first extension of the filter.

DefaultExt should be set to the extension without a ..
Meaning that in your example dlg.DefaultExt = ".bmp"; you need to change ".bmp" to "bmp"...

Answer 2

DefaultExt is the extension that will be used if the user selects a file name with no extension (atleast that's my understanding from reading the description from MSDN).

When the user of your application specifies a file name without an extension, the FileDialog appends an extension to the file name.

You may have to make bmp the first item in the filter list.