Load .png to TImage in Embarcadero C++Builder XE5

Question

I need to load a .png image because i need it's transparency. It's not an option to convert it for example in bmp because i lose it's transparency. How can I do that?

Answer 1

Just add an include for stdimage.hpp.

At designtime, this will make .png files available in the Image.Picture dialog. At runtime, you can create and load a TPngImage with the file, and assign it to the Image.Picture.

#include <stdimage.hpp>

__fastcall TForm1::TForm1(TComponent* Owner)
    : TForm(Owner)
{
  TPngImage* img = new TPngImage();
  img->LoadFromFile("C:\\Images\\calculator.png");
  Image1->Picture->Assign(img);
  delete img;
}

(Delphi code and explanation included as well as C++ Builder, because the TImage and TPngImage are both Delphi classes and therefore it's relevant, and because C++ Builder users should be pretty familiar with translating Delphi code as the entire VCL is built on it. Also, as TImage is a Delphi VCL component, a Delphi user may find the question and find the information useful as well.)

procedure TForm4.Button1Click(Sender: TObject);
var
  Png: TPngImage;
begin
  Png := TPngImage.Create;
  try
    Png.LoadFromFile('C:\Images\calculator.png');
    Image1.Picture.Assign(Png);
  finally
    Png.Free;
  end;
end;

More info in the XE5 documentation

Answer 2

In C++ Builder the code might look like this:

#include <pngimage.hpp>
....
std::auto_ptr<TPngImage> img(new TPngImage());
img->LoadFromFile(...);
Image1->Picture->Assign(img);