1) you need have the "source .PAS" file and run your app in DEBUG mode!!! 1.1) if you want stop in any other ".PAS" (for example, in another library third-party) then, you need have the "source .PAS files" too! 1.2) if you want stop in RTL/VCL library, just open the file .PAS (ex. System.Classes.pas), mark the line with breakpoint, as you done in your code!
2) you need mark (breakpoint it) where you need stop before execute the code
ex.:
if ( a = b ) then <---- breakpoint here ShowMessage( ' a = b ');
3) if you are try verify where the code is really been executed, then, you can press the "F7" key, when the breakpoint was stopped
ex.:
if ( a = StrToInt( b ) ) then <---- breakpoint here, now press F7 ShowMessage( ' a = b ');
4) Warning: in System functions, there is not sources!!! then, you can not stop in breakpoint!!!
5) when you dont have the source files, DCU (Debug mode), the IDE show the "CPU Window" with assembly mode!
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The higher the degree, the greater the respect given to the humblest!RAD 11.3