Delphi Programming Diary - Jitendra Kumar

Delphi produces various files for each project, and we should know what they are and how they are named.  Basically, two elements have an impact on how files are named: the names you give to a project and its units,  and the predefined file extensions used by Delphi. You will find the files in the directory where a Delphi project resides. Following table shows the extensions of the files and when or under what circumstances these files are created and their importance for future compilations.

If you plan on writing Delphi code that should work with several versions of the Delphi compiler then we first need to know under which versions our code gets compiled.  Suppose you are writing your own (commercial) custom component. Users of your component might have different Delphi versions than you have.  If they try to recompile the component's code - they might be in trouble! What if you were using default parameters in your  functions and the user has Delphi 3? These are symbols that can be used in $IFDEF /$ENDIF conditional compilation directives. {$IFDEF VER40}  - Turbo pascal 4 {$IFDEF VER50}  - Turbo pascal 5 {$IFDEF VER55}  - Turbo pascal 5.5 {$IFDEF VER60}  - Turbo pascal 6 {$IFDEF VER70}  - Borland pascal 7 (And turbo pascal 1.5 for windows) {$IFDEF VER80}  - Delphi 1 {$IFDEF VER90}  - Delphi 2 {$IFDEF VER100} - Delphi 3 {$IFDEF VER120} - Delphi 4 {$IFDEF VER130} - Delphi 5 {$IFDEF VER140} - ...

Hints, we also call Tool Tips are used to show some information related to an action for Users. By default it displays in a separate yellow color window  when we move mouse on buttons, menus etc. But we can create our own customized Hint also. So in this blog I will give a brief idea about use of Hints  in our Delphi application. We will also check how to customize or create a new Hint as per our requirement. Display Hint for individual Controls In Delphi every run time visible component/control and form has 2 main properties Hint and ShowHint which are used to display Hints.  Hint property is Sting type used to set the Hint text.  ShowHint is Boolean type used to whether display hint or not. Here I created a form and put some controls on that. And I set Hint and Showhint property for Button at design time. Now at run time we can see the hint when we move mouse on button as follow We can set the same properties for other controls in code als...