When my application throw an error, windows error dialog shown

Question

I developing windows form application in c#.net. Sometimes my program throw an error, windows error dialog shown (Please tell Microsoft about this problem, Send error report, Dont sent, bla bla...). I dont know why this dialog shown. What happening on my program?

Answer 1

I dont know why this dialog shown.

Because you don't handle the exception in your program, indicating a bug. Windows' default resort is the shown dialog. Your job is to either prevent or handle all potential exceptions in your code, Windows doesn't do this for you (or rather, it does; only not to your liking).

Answer 2

Just to extend Konrad's answer. You can handle expected errors using a try..catch.

try
{
    // operation that may throw an error
}
catch(Exception ex)
{
    // handle the exception. 
    // You might tell the user about the error with a messagebox
}