Show File types in OpenFileDialog in .Net

This explains how to show only selected file types in the open file dialog in c# using Filter Property

OpenFileDialog in c# allows to open the files from the physical location accessible to the c# program from the system

To show all files filter in the dialog, you can use this
openFileDialog1.Filter = "All files (*.*)|*.*";

To show both gif files and png files, you can use this
openFileDialog1.Filter = "Gif files (*.gif)|*.gif|Png files (*.png)|*.png";

You can have any number of file types associated to this seperated by | symbol.

You could also set the default type to be selected by using FilterIndex property
openFileDialog1.FilterIndex = 1;