How to make any control shape irregular in c#

how to make any control of win application transparent. i want that i will assign a background image for the target control and will invoke a routine and that routine will create that control transparent in such a way that only image will visible. as a example suppose image has assign to picture box. the picture shape is not square rather irregular. if i can make picture box transparent then user will see the image only. basically i want to make a picture box or any control irregular shape. how to achieve 开发者_开发技巧it through code in c#.

thanks

In WPF, transparency is quasi for free. For the image-element, assign a png-image with an alpha mask and the image will be rendered with active transparency.

For controls with an solid background, you generally have to set the Background to a transparent Brush:

If you want to make a whole window partial transparent, you have to remove the border, set the window style to none, set the background brush to a transparent brush, and set the AllowsTransparency-property of the window to true.

there is one for ordinary winform at http://www.youtube.com/watch?v=K_JzL4kzCoE