CFileDialog OnTypeChange issue

[_Flaviu]

I derived a class from CFileDialog, named CFileDialogExt. I override OnTypeChange, just like this:

void CFileDialogExt::OnTypeChange()
{
// TODO: Add your specialized code here and/or call the base class

switch(GetOFN().nFilterIndex)
{
case 1:
	SetDefExt(\_T("bmp"));
	break;
case 2:
	SetDefExt(\_T("gif"));
	break;
case 3:
	SetDefExt(\_T("jpg"));
	break;
case 4:
	SetDefExt(\_T("png"));
	break;
case 5:
	SetDefExt(\_T("tiff"));
	break;
}

CFileDialog::OnTypeChange();

}

Default type is bmp. I type "aaa" as file name. I change the type (from combo type), as gif. The file name is still "aaa". I change again as jpg, the file name is changed as "aaa.gif" !! Is delayed by one changing ... strange ... why ? Furthermore, I change extension as tiff, the file name is "aaa.jpg", not "aaa.tiff" .... I have done wrong here ?