write a ValidationExpression of asp:RegularExpressionValidator for uploading the images

Question

I wanted to upload images (Jpgs and Gifs) only so what is the ValidationExpression of asp:RegularExpressionValidator for uploading the images.

Puran Kaushal · Answer

I tried the expression ^.+\.((jpg)|(gif)|(jpeg))$ and it worked for me in a RegularExpressionValidator. The only problem was with the string case. I didn't find a way to specify that the regular expression is case insensitive for the RegularExpressionValidator. The expression can be rewritten to ^.+\.(([jJ][pP][eE]?[gG])|([gG][iI][fF]))$ to allow extensions like jPeG etc