Why "GDI+ Window" visible?

[Gary]

Each GDI+ instance contains a hidden top-level window whose title is "GDI+
Window" and whose class name is GDI+ Hook Window Class.

But in my program, sometimes the "GDI+ Window" appeared in the system
toolbar, and can't close that. And the program still works correctly.

I don't know why the window became visible. It happens randomly and can't
catch the event in the code.

Anyone can give me an advice?

Thanks

 

[Bob Powell [MVP]]

I've never seen this occur before. Can you post some code or perhaps send me
the code that duplicates this problem.

Just take the spam killer out of my e-mail address to send directly to me.

--
Bob Powell [MVP]
Visual C#, System.Drawing

Ramuseco Limited .NET consulting
http://www.ramuseco.com

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[Gary]

It's difficult for us to locate the codes that raise the GDI+ Window,
because
1. If it were an exception in the program, no "try..catch" block could grasp
the exception.
2. When the GDI+ Window displays, the application, which raises the GDI+
window, can run normal.
3. When the GDI+ Window displays, the user cannot read the whole window. The
GDI+ Window can only show its exitent on the Task Bar under the Desktop
screen.
4. The GDI+ window appears only occasionally. For example, a general
operation, which the user does every day, may cause the display of the GDI+
Window, but the same operation must not cause the display of the GDI+ Window
during the next 15 days. The operations that cause the display of the GDI+
Window are not determinated. Sometimes, it's to refresh the records in the
ListView control, sometimes, it's to print the report, or so on.