Wrong condition in D3DRender.D3DImageIsFrontBufferAvailableChanged

[MatriXiao88]

Hardware configuration

1. Intel Celeron CPU J1900 1.99GHZ
2. RAM:4G
3. Integrated graphics card:Intel HD Graphics

Reproduce

1. Preview camera with wpfMediaKit
2. Put the computer to sleep
3. Wake the computer up after step 2
4. Repeat setp 1-3 above multiple times, the application will be black out.

Other information

• D3DDevice lost when application is black out

• Notice the event D3DImage.IsFrontBufferAvailableChanged is fired, but I find some problem in method, D3DRender.D3DImageIsFrontBufferAvailableChanged.

      private void D3DImageIsFrontBufferAvailableChanged(object sender, DependencyPropertyChangedEventArgs e)
      {
          //I think the condition below is wrong. When D3D device lost, D3DImage.IsFrontBufferAvailable is false all the time.
          if (!D3DImage.IsFrontBufferAvailable)
              return;
  
          m_newSurfaceAvailable = true;
          SetBackBufferInternal(m_pBackBuffer);
      }

[xmedeko]

@Rhuaer is this issue similar/duplicate to #42 and #3?

[MatriXiao88]

@xmedeko yeah, I will try it with BobDeCuir's suggestion. Please close this issue. Thanks.

[xmedeko]

May you suggest some PR, or some HOWTO manual for other users?

[MatriXiao88]

@xmedeko I have created a pull request. see #62