Stop the execution of the program Delphi XE

Question

On the form of two buttons - Button1 and Button2. In Button1, when pressed, a loop is performed, reading a text, processing and saving the result.

How you can implement: Stop the loop when you click the Button2 button:

var f1,f2:TextFile; s:string; i:integer; ................................... ///////////////Я так поняла где то вот тут нужно вставить условие ? while not Eof(f1) do begin Application.ProcessMessages; /////// что бы программа не зависала Readln(f1,s); s := AnsiUpperCase(s); Writeln(f2,s); end; CloseFile(f1); CloseFile(f2); end;

@Anton Shchyrov, I am grateful for the answer, but the question is: Why is Application.ProcessMessages a harmful and dangerous function?

Anton Shchyrov Anton Shchyrov 23.5k 2 14 44 · Accepted Answer · 2018-06-10T21:28:33

Throw Application.ProcessMessages as one of the most harmful and dangerous functions.
Move the execution of Button1Click code to a separate thread

Cycle condition

 while not Eof(f1) do begin

replaced by

 while not Terminated and not Eof(f1) do begin

In the Button2Click handler Button2Click write MyThread.Terminate;

I am grateful for the answer, but the question is: Why is Application.ProcessMessages a harmful and dangerous function?
Harmful, because it disaccreats to think and provokes to do as quickly, and not as more correctly (the second such function is Sleep except for debugging, and in exceptional cases).
And dangerous, because during the execution of the cycle, the form is active and it can, for example, close or press the start button again.

Stop the execution of the program Delphi XE

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