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releasing resources with IExportBmp

Question asked by Iain3.14159 on Mar 16, 2015
Latest reply on Mar 18, 2015 by Iain3.14159

Hi

I am writing a program to render a map as a in-memory Bitmap that then sends the data to another application.

 

I've followed the ExportJpg example here.

ArcObjects 10 .NET SDK Help

 

The problem is the exporter creates a GDI HBitmap.  I want a .Net Bitmap so I'm using Systems.Drawing.Image.FromHbitmap()

Microsoft sdk Image.FromHbitmap Method (IntPtr) (System.Drawing) says that you have to use the gdi32.dll call to DeleteObject() to release the GDI Object manually after using FromHbitmap().

 

What I am finding is that the GDI handle that is created by FromHBitmap is never released and the program leaks a GDI Object every time the new bmp is exported.

 

// activeView and exportBmpClass are already setup similar to ExportJPJ example

Int32 hDC = exportBmpClass.StartExporting(); // Creates 1 DC and 1 HBitmap
activeView.Output(hDC, (int)exportBmpClass.Resolution, ref exRect, null, null); //renders activeview to the hDC/ HBitmap

Bitmap bmp = Image.FromHbitmap((IntPtr)exportBmpClass.Bitmap, (IntPtr)exportBmpClass.Palette); // creates 1 HBitmap

DeleteObject((IntPtr)exportBmpClass.Bitmap); // gdi32.dll call does not release a HBitmap!

exportBmpClass.FinishExporting(); // releases 1 DC
exportBmpClass.Cleanup(); //releases 1 HBitmap

// rest of code, do stuff with the .Net bmp ...

 

Any ideas? 

 

Thanks

Iain

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