Access Violation Error During OnRender()

[Zeos6]

Hi,

I am using RenderTarget.DrawGeometry() in my indicator to paint a custom shape in OnRender(). Works great and no problem. Today I added a method to draw text using RenderTarget.DrawTextLayout() and I am getting Access Violation errors relating to writing to protected memory. Huh?

Is this a device context issue or a factory issue or something altogether that I am missing? If I get rid of the text writing method, all is good. The moment I add the text writing method, I get the error. I call the text method from inside the shape drawing method during OnRender().

Any suggestions how to debug this would be greatly appreciated. Thank you.

EDIT: I wonder if this occurs because I have multiple Render targets: the shape and the text.How should I handle multiple Render targets?

[NinjaTrader_ChelseaB]

Hello Zeos6,

I have an example of rendering text with DrawTextLayout().

[Zeos6]

Thank you for your reply ChelseaB. Unfortunately your reply does not address my question. I know how to render text with DrawTextLayout() and I know how to render shapes with RenderTarget.DrawGeometry(). The problem I am having is as follows...

1. I render a shape using RenderTarget.DrawGeometry().
2. I try to render text with DrawTextLayout()

It is on this step 2 that I get the access violation error.
I can do step 1 alone and I can do step 2 alone. How do I do them in combination when step 1 calls the method of step 2?

EDIT: I am starting to think that this is RenderTarget issue as there are multiple targets.

[NinjaTrader_ChelseaB]

Hello Zeos6,

Without seeing the code its hard to say whats wrong..

It might be a brush that's not being reconstructed in OnRenderTargetChanged().

There will only be one RenderTarget at a time, but this does get destroyed and recreated throughout the life of the chart.

[Zeos6]

Hi ChelseaB,

Thank you for the reply. I think you are correct in that it likely deals with a brush and/or a stroke not being reconstructed during OnRenderTargetChanged(). Do you have a sample code snippet that reconstructs a brush and a stroke during OnRenderTargetChanged()? I have been playing with this for two days now and just seem to be missing something.Thank you.

EDIT: Figured it out. Thanks ChelseaB. Was disposing a brush needed in step 1 in the method of step 2.Once I corrected this, everything works fine now.