C Builder 5 and WinAPI, TransparentColor-CodePudding

What could be the alternative to TransparentColor and Transparent properties coming from CBuilder6, but absents of TForm in CBuilder5...

any WINAPI clue ?

CodePudding user response：

SetLayeredWindowAttributes can specify one color as a transparent color.
SetWindowRgn can also be used (and must be used on versions before Win2000). It however requires you to build the mask by yourself.

CodePudding user response：

Here is my best answer :

void __fastcall TForm1::FormCreate(TObject *Sender) 

{ this->Align = ::alClient;
  this->Color = TColor(RGB(255, 255, 255)); 
 
 ::SetWindowLongPtr(this->Handle, GWL_EXSTYLE, WS_EX_LAYERED); 
 ::SetLayeredWindowAttributes(this->Handle, ::ColorToRGB(this->Color), 255, LWA_COLORKEY); 
}

Notice that I was compelled to have the TForm's Align property set to ::alClient...so the TForm became clickable even with LayerAttribute set to a COLOR_REF...

Thanks all... That, now, is usable...