Delphi ActiveX

Decode Base64 Image String (GIF, JPG, etc.) and Save to File

I have an XML response that includes a base 64 encoded image string (UPS label). It's a huge string and I need to save it as a gif file on my users pc.

This example shows how to do it..

Delphi ActiveX

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Integer;
bd: TChilkatBinData;
x: WideString;
xml: TChilkatXml;
gifBase64: WideString;

begin
success := 0;

bd := TChilkatBinData.Create(Self);

// I created an extra-small GIF image for this example..
success := bd.LoadFile('qa_data/gif/xsmall.gif');
if (success <> 1) then
  begin
    Memo1.Lines.Add('Failed to load GIF image file.');
    Exit;
  end;

// Show GIF bytes as base64:
Memo1.Lines.Add(bd.GetEncoded('base64'));

// This particular GIF in base64 is this:
// R0lGODlhBQAFAMQAAAAAAP////z8/PHx8evr6+jo6OHh4d7e3sPDw8LCwpqamo2NjWxsbGRkZFpaWk1NTUtLS0hISCwsLCQkJP///wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACH5BAEAABQALAAAAAAFAAUAAAUTYCAYQUBAU1lI0TIgztE8jFImIQA7

// Let's begin with an XML string:
x := '<abc><def>R0lGODlhBQAFAMQAAAAAAP////z8/PHx8evr6+jo6OHh4d7e3sPDw8LCwpqamo2NjWxsbGRkZFpaWk1NTUtLS0hISCwsLCQkJP///wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACH5BAEAABQALAAAAAAFAAUAAAUTYCAYQUBAU1lI0TIgztE8jFImIQA7</def></abc>';

xml := TChilkatXml.Create(Self);
success := xml.LoadXml(x);

// Get the base64 string:
gifBase64 := xml.GetChildContent('def');

Memo1.Lines.Add(gifBase64);

// Load bd with the base64 decoded bytes.  
bd.Clear();
bd.AppendEncoded(gifBase64,'base64');

// Save to a GIF file.
success := bd.WriteFile('qa_output/xsmall.gif');
end;