问题
I'm using the ToolStripDropDown
to show up an selectionpopup.
The ToolStripDropDown
contains a few custom controls with running Threads.
The Threads ends with the OnHandleDestroyed event, but for some reason the ToolStripDropDown
doesn't dispose/destroy it's handle after closing.
Disposing the ToolStripDropDown
on the closed-event gives me an exception because anything still accesses the ToolStripDropDown.
How do I know if the custom Control is still in use or not to end the thread?
Custom-Control:
public class CControl : Control
{
Thread StyleThread;
Object lockOBJ = new Object();
bool abortthread = false;
public CControl()
{
this.SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.UserPaint | ControlStyles.OptimizedDoubleBuffer, true);
this.SetStyle(ControlStyles.Selectable, false);
StyleThread = new Thread(new ThreadStart(this.StyleDelegate));
}
protected override void OnHandleCreated(EventArgs e)
{
base.OnHandleCreated(e);
if(!StyleThread.IsAlive)
StyleThread.Start();
}
protected override void OnHandleDestroyed(EventArgs e)
{
base.OnHandleDestroyed(e);
lock (lockOBJ)
{
abortthread = true;
}
if (StyleThread.IsAlive)
{
StyleThread.Join(100);
}
}
...
}
ToolStripDropDown-Control:
public class AddPopUp : UserControl
{
/*
------------------------------------
This Control contains some CControls
------------------------------------
*/
public void Show(Control control)
{
TSDD tsdd = new TSDD(this);
Point screenpoint = control.PointToScreen(new Point(0, 0));
tsdd.Show(control,new Point(0, -tsdd.Height ));
}
class TSDD : ToolStripDropDown
{
private Control Control { get; set; }
public TSDD(Control control)
{
this.Control = control;
this.DropShadowEnabled = false;
ToolStripControlHost ch = new ToolStripControlHost(control);
this.Items.Add(ch);
}
protected override void SetBoundsCore(int x, int y, int width, int height, BoundsSpecified specified)
{
base.SetBoundsCore(x, y, Control.Size.Width + 16, Control.Size.Height + 18, specified);
}
protected override CreateParams CreateParams
{
get
{
CreateParams cp = base.CreateParams;
unchecked
{
cp.Style |= (int)0x80000000;
cp.Style |= 0x40000;
}
return cp;
}
}
protected override void WndProc(ref Message m)
{
if (m.Msg == 0x84)
{
m.Result = (IntPtr)1;
return;
}
base.WndProc(ref m);
}
}
}
EDIT:
After same more testing i wasn't able to dispose the toolstripdropdown. As a workaround i'm just destroying the handle on close of the toolstripdropdown.
protected override void OnClosed(ToolStripDropDownClosedEventArgs e)
{
base.OnClosed(e);
this.DestroyHandle();
}
回答1:
ToolStrips have a very persistent bug (claimed to be fixed, but I still have problems) where they register an event handler to SystemEvents.UserPreferenceChanged to be able to repaint if the user changes global style settings in the OS.
The only workaround I have found is to remove the attached toolstrips by enumerating the handlers in the SystemEvents.UserPreferenceChanged and removing them upon disposal of the control.
ToolStrip memory leak
http://connect.microsoft.com/VisualStudio/feedback/details/115600/toolstrip-leaks-after-calling-dispose#
来源:https://stackoverflow.com/questions/6826958/c-toolstripdropdown-doesnt-dispose-destroyhandle