SysUtils.ChangeFileExt Function

Changes the extension of a file name.

Pascal

function ChangeFileExt(const FileName: string; const Extension: string): string; overload;

C++

AnsiString ChangeFileExt(const AnsiString FileName, const AnsiString Extension);

File

SysUtils

Description

ChangeFileExt takes the file name passed in FileName and changes the extension of the file name to the extension passed in Extension. Extension specifies the new extension, including the initial dot character.

ChangeFileExt does not rename the actual file, it just creates a new file name string.

Note: This function works with multi-byte character sets (MBCS).

C++ Examples:

Copy Code

/*
This example converts a specified icon to a bitmap. To run 
this example, add an image, a button, and an Open dialog to 
a form. Name the button ConvertIcon2Bitmap, and add the 
following code as its OnClick event handler.
*/

#include <memory>       //for STL auto_ptr class

void __fastcall TForm1::ConvertIcon2BitmapClick(TObject *Sender)
{
  OpenDialog1->DefaultExt = ".ICO";
  OpenDialog1->Filter = "icons (*.ico)|*.ICO";
  OpenDialog1->Options << ofOverwritePrompt << ofFileMustExist << ofHideReadOnly;
  if (OpenDialog1->Execute())
  {
    std::auto_ptr<TIcon> pi(new Graphics::TIcon);
    AnsiString as;
    pi->LoadFromFile(OpenDialog1->FileName);
    as = ChangeFileExt(OpenDialog1->FileName,".BMP");
    Image1->Width = pi->Width;
    Image1->Height = pi->Height;
    Image1->Canvas->Draw(0, 0, pi.get());
    Image1->Picture->SaveToFile(as);
    ShowMessage(OpenDialog1->FileName + " Saved to " + as);
  }
}

Delphi Examples:

Copy Code

{
This example converts a specified icon to a bitmap. To run 
this example, add an image, a button, and an Open dialog to 
a form. Name the button ConvertIcon2Bitmap, and add the 
following code as its OnClick event handler.
} 
procedure TForm1.ConvertIcon2BitmapClick(Sender: TObject);
var 
  s : string;
  Icon: TIcon;
begin
  OpenDialog1.DefaultExt := '.ICO';
  OpenDialog1.Filter := 'icons (*.ico)|*.ICO';
  OpenDialog1.Options := [ofOverwritePrompt, ofFileMustExist, ofHideReadOnly ];
  if OpenDialog1.Execute then
  begin
    Icon := TIcon.Create;
    try
      Icon.Loadfromfile(OpenDialog1.FileName);
      s:= ChangeFileExt(OpenDialog1.FileName,'.BMP');
      Image1.Width := Icon.Width;
      Image1.Height := Icon.Height;
      Image1.Canvas.Draw(0,0,Icon);
      Image1.Picture.SaveToFile(s);
      ShowMessage(OpenDialog1.FileName + ' Saved to ' + s);
    finally
      Icon.Free;
    end;
  end;
end;