Using SaveToFile causes Exception

[Chesterton_Andrew]

Hi
I am using Delphi XE8 with TMS Diagram Studio V4.24.01

Using the built in editor TDiagramEditor (editor) I can save and load a file using the file open and save buttons on the editor.

When programmatically saving a file using editor.Diagram.SavetoFile() which essentially executes the same code as the editor buttons. I get an exception '$C0000005 ACCESS VIOLATION'.

Any help would be appreciated.

AndyC

[wlandgraf (Wagner Landgraf)]

Please provide more details, specially because you said the built-in code works, and your custom code doesn't not. We cannot guess what's going on at your side. Code you are using, offending line, call stack, etc.

[Chesterton_Andrew]

In the supplied Demos\Simple\DiagramDemo a made the following changes

unit fMain;

…

In TForrm1 class..

private

procedure EditorCreate(Sender: TObject);

• procedure EditorSave(Sender: TObject);

In TForm1.FormCreate..

DiagramEditor1.OnCreateDesigner := EditorCreate;

• DiagramEditor1.OnSaveDiagram := EditorSave;

DiagramEditor1.Execute;

• // ADDED THIS PROCEDURE TO FORCE SAVING TO SINGLE FILE

• //

• procedure TForm1.EditorSave(Sender: TObject);

• begin

[wlandgraf (Wagner Landgraf)]

And what is the content of EditorSave procedure? Can you please properly format the message and provide the correct information?

[Chesterton_Andrew]

The following was sent via email. Looks like the forum messed it up a bit lol.

In the supplied Demos\Simple\DiagramDemo a made the following changes

unit fMain;
…

In TForrm1 class..

  private
    procedure EditorCreate(Sender: TObject);
+   procedure EditorSave(Sender: TObject);


In TForm1.FormCreate..

  DiagramEditor1.OnCreateDesigner := EditorCreate;
+ DiagramEditor1.OnSaveDiagram := EditorSave;    
  DiagramEditor1.Execute;


+  // ADDED THIS PROCEDURE TO FORCE SAVING TO SINGLE FILE
+  //
+  procedure TForm1.EditorSave(Sender: TObject);
+  begin
+
+   TfmDiagramEditor(Sender).Diagram.SaveToFile('tempfille.dgr');
+   
+    // ALSO TRIED BELOW
+    // diagramEditor1.Diagram.SaveToFile('tempfile.dgr');
+

When I the save the file I get the exception.
This break’s here

procedure TatDiagram.SaveToFile(const AFileName: string);
var
  MemStream: TMemoryStream;
  FileStream: TFileStream;
begin
  MemStream := TMemoryStream.Create;
  try
    FileStream := TFileStream.Create(AFileName, fmCreate);
    try
>>    SaveToStream(MemStream);
      MemStream.Seek(0, soFromBeginning);
      ObjectBinaryToText(MemStream, FileStream);
    finally
      FileStream.Free;
    end;
  finally
    MemStream.Free
  end;
end;

Please let me know if you need more information.
Thanks
AndyC

[wlandgraf (Wagner Landgraf)]

@Chesterton_Andrew

TfmDiagramEditor(Sender).Diagram.SaveToFile('tempfille.dgr');

You can't cast Sender to TfmDiagramEditor, as it's not such class, but just a TAction descendant.

[Chesterton_Andrew]

Ok. Then how can i use the OnSaveDiagram event to save the Diagram?

[wlandgraf (Wagner Landgraf)]

From OnEditorCreate event you can save a reference to the TatDiagram object, and then reuse it in the OnSaveDiagram event. The diagram reference is never modified until you close the editor.

[Chesterton_Andrew]

Sorted now
Thanks for that.