[C#] Extension Filter

[Chad]

You may want to start using ternary operators for those simple true/false if statements. Those five lines can be shortened to:

 return (Block.Contains(Extension)) ? false : true; 
  

Also, it's not a good idea to rely on the filename passed by through the user as the determent for the file type. I can save an executable file as .jpg, and it would pass your blacklist, whereas it should get blocked. Food for thought

I honestly completely forgot about ternary. Thanks for reminding me.