How to find issue in XAML that causes code crash

I wrote a Radio Button style.

When a page containing a Radio button, that has the style implementation I wrote. is shown I get crash and I don't know why.

After I examined the xaml more than 8 times - I found the bug.

But I still want to ask some important question ==> How can i find bugs like this in the future ?

There are no place to add 'br开发者_开发百科eakpoints' in the code to stop the code and look if my input is wrong or to look for some algorithm flow.

Thanks for help.