SRL Archive - Delphi/FPC Help and Tutorials

(Sorry for stupid title.)

Basically, this is an example of a program I want to be able to make.
Main thing I'm wondering about, is how do I make the background transparent – and how do I make it draggable?

Short: Need to make an app that displays a draggable image on my desktop with a transparent background, i.ex. some sort of mascot. Preferably animated.

type
 TForm1 = class(TForm)
   procedure CreateParams(var Params:TCreateParams); override;
   procedure FormCreate(Sender: TObject);
 private
   { Private declarations }
 public
   { Public declarations }
 end;

var
 Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.CreateParams(var Params:TCreateParams);
Begin
 inherited CreateParams(Params);
 Params.ExStyle:=WS_EX_TRANSPARENT;
End;

procedure TForm1.FormCreate(Sender: TObject);
begin
 Form1.Brush.Style:=bsClear;
 Form1.BorderStyle:=bsNone;
end;

Source

You'll have to handle the moving yourself.

I couldn't download your program, but I think this is what you want?

Ah, thanks a lot, Niels. Sorry for ignoring this for so long, but as I really am not any good with Delphi, motivation hasn't been on top.. Anyway, this is what I have so far:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, pngimage, ExtCtrls, ImgList;

type
 TForm1 = class(TForm)
    Image1: TImage;
   procedure CreateParams(var Params:TCreateParams); override;
   procedure FormCreate(Sender: TObject);
 private
   { Private declarations }
 public
   { Public declarations }
    procedure WMNCHitTest(var M: TWMNCHitTest);
      message wm_NCHitTest;
 end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.CreateParams(var Params:TCreateParams);
begin
  inherited CreateParams(Params);
  Params.ExStyle:=WS_EX_TRANSPARENT;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  BorderStyle:=bsNone;
  Brush.Style:=bsClear;
  Width:=Image1.Width;
  Height:=Image1.Width;
end;

procedure TForm1.WMNCHitTest(var M: TWMNCHitTest);
begin
  inherited;
  if (M.Result = htClient) then
    M.Result := htCaption;
end;

end.

Thing is, whenever I move the form around, the background of the form doesn't refresh. Any tips?

Shouldn't

  Height:=Image1.Width;

be

  Height:=Image1.[B]Height[/B];

Also, I think you should be able to refresh it with:

  Self.Refresh;
  Image1.Refresh;

Thanks for pointing out the width/height thingy.
As for refreshing, it didn't help. Neither did Repaint;

From: EvilChicken!
Thing is, whenever I move the form around, the background of the form doesn't refresh. Any tips?

What do you mean it "doesn't refresh"?

From: r!ch!e
Shouldn't
Also, I think you should be able to refresh it with:

  Self.Refresh;
  Image1.Refresh;

The statement, Image1.Refresh is unnecessary, as when you call Self.Refresh it forces and invalidates its client area, redraws itself and likewise for its' child components.

@^: the supposedly "bsClear" area stays the same as to what it was at FormCreate, so the form background is simply a segment of the compiler in the background.

Sorry for not being able to post any screens, I'm at my girlfriend's place at the moment.