TcxGrid Column动态添加Image

      MyCol := TcxColumn.Create;

            ...



            MyCol.PropertiesClass := TcxImageProperties;

            ImageProps := TcxImageProperties(MyCol.Properties);

            ImageProps.Center := True;

            ImageProps.GraphicClassName := '';

            ImageProps.OnGetGraphicClass := GetThumbnailGraphicClass;

            ImageProps.Stretch := True;

            ...



Procedure GetThumbnailGraphicClass:



procedure TCORSA.GetThumbnailGraphicClass(AItem: TObject;

  ARecordIndex: Integer; APastingFromClipboard: Boolean;

  var AGraphicClass: TGraphicClass);

begin

  if AnsiSAmeText(FThumbNailExtension, '.TIF') then

      AGraphicClass := TGraphicClass(GetClass('TTiffGraphic'))

  else

  if AnsiSAmeText(FThumbNailExtension, '.JPG') then

      AGraphicClass := TGraphicClass(GetClass('TJPEGImage'))

end;



The actual thumbnail data is loaded into the grid via streams:



                MStream := TMemoryStream.Create;

                Stream := TStringStream.Create('');



                MStream.LoadFromFile(ThumbNail);

                Stream.CopyFrom(MStream, MStream.Size);



                FActiveGrid.DataController.SetValue(RowInfo.RecordIndex,

                                                    ThumbCol,

                                                    Stream.DataString);

 

改进后的：

　

function StreamToVar(Stream: TStream): OleVariant;

var

      P: Pointer;

begin

  Result := VarArrayCreate([0, Stream.size -1],Varbyte);

  P := VarArrayLock(Result);

  Try

    Stream.Position := 0;

    Stream.Read(P^, Stream.size);

  Finally

    VarArrayUnlock(Result);

  end;

end;

procedure TForm1.Button1Click(Sender: TObject);

var

  IRecIdx  :  Integer;

  stream : TMemoryStream;

begin

  with cxGrid1TableView1.DataController do

  begin

    IRecIdx := AppendRecord;

    stream := TMemoryStream.Create();

    stream.LoadFromFile('H:\pic\随拍\IMAG0002.jpg');

     stream.Position := 0;

    Values[IRecIdx,0] := StreamToVar(stream);

    stream.Free;

    Post;

  end;

end;