Steema Central

Code: Select all

unit Unit1;
interface
uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, VclTee.TeeGDIPlus, Vcl.StdCtrls,
  Vcl.ExtDlgs, VCLTee.TeEngine, Vcl.ExtCtrls, VCLTee.TeeProcs, VCLTee.Chart,
  VCLTee.Series, Vcl.Imaging.jpeg;

type
  TForm1 = class(TForm)
    Chart1: TChart;
    SavePictureDialog1: TSavePictureDialog;
    ExportBtn: TButton;
    Series1: TFastLineSeries;
    procedure FormCreate(Sender: TObject);
    procedure ExportBtnClick(Sender: TObject);
  private
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

(*___________________________________________________________________________*)

function GetChartJPEG(AChart:TCustomChart): TJPEGImage;
var tmpBitmap:TBitmap;
begin
  Result:=TJPEGImage.Create;   { <-- create a TJPEGImage }
  tmpBitmap:=TBitmap.Create;   { <-- create a temporary TBitmap }
  try
    tmpBitmap.Width :=AChart.Width;   { <-- set the bitmap dimensions }
    tmpBitmap.Height:=AChart.Height;
    { draw the Chart on the temporary Bitmap... }
    AChart.Draw(tmpBitmap.Canvas,Rect(0,0,tmpBitmap.Width,tmpBitmap.Height));
    { set the desired JPEG options... }
    With Result do
    begin
      GrayScale            := False;
      ProgressiveEncoding  := True;
      CompressionQuality   := 100;  // % 0 - 100
      PixelFormat          := jf24bit;  // or jf8bit
      ProgressiveDisplay   := True;
      Performance          := jpBestQuality;  // or jpBestSpeed
      Scale                := jsFullSize;  // or jsHalf, jsQuarter, jsEighth
      Smoothing            := false;
      { Copy the temporary Bitmap onto the JPEG image... }
      Assign(tmpBitmap);
    end;
  finally
    tmpBitmap.Free;  { <-- free the temporary Bitmap }
  end;
end;

procedure TForm1.ExportBtnClick(Sender: TObject);
var
  FName: string;
begin
  SavePictureDialog1.Filter := 'JPG-Datei (*.jpg)|*.jpg';
  if not SavePictureDialog1.Execute then Exit;
  FName := SavePictureDialog1.FileName;
  if ExtractFileExt(FName) = '' then FName := FName + '.jpg';

  with GetChartJPEG(Chart1) do begin
    SaveToFile(FName);    { <-- save the JPEG to disk }
    Free;  { <-- free the temporary JPEG object }
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Series1.FillSampleValues(500);
end;

end.

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procedure TForm1.ExportBtnClick(Sender: TObject);
var
  FName: string;
  OldCanvas : TCanvas;
begin
  OldCanvas := Chart1.Canvas.ReferenceCanvas;

  SavePictureDialog1.Filter := 'JPG-Datei (*.jpg)|*.jpg';
  if not SavePictureDialog1.Execute then Exit;
  FName := SavePictureDialog1.FileName;
  if ExtractFileExt(FName) = '' then FName := FName + '.jpg';

  with GetChartJPEG(Chart1) do begin
    SaveToFile(FName);    { <-- save the JPEG to disk }
    Free;  { <-- free the temporary JPEG object }
  end;

  Chart1.Canvas.ReferenceCanvas := OldCanvas;
end;

Code: Select all

TeeSavePanel(TJPEGExportFormat,AChart);