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Commented Issue: Native Exception in AlphaImage Draw method [3720]

INTPnerd — Fri, 12 Nov 2010 02:28:25 GMT

The problem is because a managed array is passed to the COM object. Once the garbage collector decides to free/move this array all hell break loose.
Here's a fix:
In IImagingFactory.cs, replace:

// We need the MarshalAs attribute here to keep COM interop from sending the buffer down as a Safe Array.
uint CreateImageFromBuffer([MarshalAs(UnmanagedType.LPArray)] byte[] buffer, uint size, BufferDisposalFlag disposalFlag, out IImage image);

With:

uint CreateImageFromBuffer(IntPtr buffer, uint size, BufferDisposalFlag disposalFlag, out IImage image);

In AlphaImage.cs add this in the top of the file:

using System.Runtime.InteropServices;

And replace:

factory.CreateImageFromBuffer(pbBuf, cbBuf, BufferDisposalFlag.BufferDisposalFlagNone, out alphaImage._image);

With:

// Copy stream data into an unmanaged global buffer that will be freed by the factory once image is decoded
// note that we cannot pass pbBuf directly since it might be moved around or freed by the gc.
IntPtr p = Marshal.AllocHGlobal((int)cbBuf);
Marshal.Copy(pbBuf, 0, p, (int)cbBuf);
factory.CreateImageFromBuffer(p, cbBuf, BufferDisposalFlag.BufferDisposalFlagGlobalFree, out alphaImage._image);
Comments: ** Comment from web user: INTPnerd **

Sweet bug fix! This really needs to be applied to the code base. The library completely unstable and unusable without this bug fix if your code uses the AlphaImage.CreateFromStream(...) or AlphaImage.CreateFromResource(...) methods at all.

Commented Issue: Native Exception in AlphaImage Draw method [3720]

oliv26 — Mon, 09 Nov 2009 16:34:17 GMT

Created Issue: AlphaPictureBox controls do not support mouse even

peter_chen — Fri, 31 Jul 2009 12:07:29 GMT

First of all, I would like to thanks to you group to share such great project to us. The question is I tried to make mouse dragable picturebox with AlphaMobileControls, but it does not work. Is any way that I can implentment this function.

Created Issue: Native Exception in AlphaImage Draw method

Statyk7 — Thu, 29 Jan 2009 01:09:04 GMT

CREATED ISSUE: No fullscreen

perettigiuliano — Fri, 16 May 2008 09:23:25 GMT

deriving a form from alphaform the application can't be run in fullscreen mode, bottom bar still remains visible