MK_CONTROL flag cleared during drag-copy operation

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I'm using Stingray Objective Views on top of MFC for a canvas editing application. I've recently started having a strange problem, where the control key setting is cleared for drag-copy operations (that is, if I have an object on the canvas and I hold the CTRL key down while moving it should make a copy instead of moving the original object).

What is strange I've found that if I put a breakpoint at the start of COleDropTarget::XDropTarget::DragOver then I can see that the MK_CONTROL flag is always set for the dwKeyState parameter, and the drag-copy works properly. But if there is no breakpoint then the MK_CONTROL flag is usually not set, even though I'm holding the CTRL key down.

Does anyone know what might be causing the problem?

Thanks, Kevin

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JohnCz On

I am not using Stingray software but. . .

The question: Was it working before? How do you know the flag is not set? If it is set with the breakpoint, it should be set without breakpoint in the same memory location.

If you are sure it is cleared, it must be cleared after the breakpoint. If it was working before and stopped (providing you are running the same version of the code) , most likely the culprit is not your app.

If it stopped working after charges, most likely changes in the code are causing this problem; it could be your code or some kind of a bug in stingray part. You have mentioned using COleDropTarget. If you have source for stingray, see if it contains any drag/drop customization.