问题
I have a DataGridView control in my Windows Forms Application. I am adding rows to the grid using a background thread. I change the form's cursor to Waitcursor when the process starts and back to Default when it ends. This works well for the form, but not for the grid. When the form's cursor is changed back to default, the grid's cursor does not change, although the cursor over the rest of the form does.
Does this have anything to do with the fact that I am updating the grid from a background thread? (The cursor is being changed from the UI thread directly).
Edit: The background process raises an event, the handler checks the InvokeRequired property of the grid and decides if it needs to "Invoke" the method again from the main thread. So, in effect the actual UI update happens from the appropriate thread. I am not sure if this means that I am "using a background thread" or not. :|
回答1:
I've had some problems doing single thread updating of my datagrids, where the datagrid did not reset to normal cursor after i've had waitcursor to true. What I did was right after i went
this.UseWaitCursor = false;
I added
DatagridviewFoo.Cursor = this.Cursor;
Maybe it's just the same problem for you
回答2:
I've had this problem as well. It was difficult to track down the cause, let alone a solution.
This issue only ever happened when I had a dialog box over the DGV control and the mouse clicked on a button to close the box such that when the box closed, the mouse was over a (resizable) column border. If the cursor ended up over a cell, the problem didn't arise. If I had to guess, I'd say the grid was seeing a column resize event as soon as the dialog box closed which wasn't properly handled.
Using Cursor.Current = Cursors.Default fixed my issue (without the need to explicitly reset the control's cursor). But maybe be aware that Application.UseWaitCursor = False didn't work even with the explicit control cursor reset.
回答3:
I had a similar problem, but neither of the posted solutions worked for me. Mine was not caused by clicking a button above a movable column separator. It just randomly happened after opening and closing a dialog box. I'm pretty sure it came down to timing because .Net/Windows has issues when it comes to setting cursors and actually having them take effect. To try to overcome that, the library we use for showing and hiding the wait cursor calls - ack! - Application.DoEvents. I set a breakpoint in OnCursorChanged and saw that the cursor was sometimes actually getting set on a latter call to Application.DoEvents (used to keep the UI responsive while waiting for the file system to release a write lock on a file). So I guess sometimes the default cursor was getting turned back on before the call to set the wait cursor had fully taken effect. Anyway, my brute-force approach is to call
Cursor = Cursors.Default;
in my override of OnCellEnter (which always happens after the grid gets refreshed following the dialog box being closed). I'm not particularly proud of this, but it seems to work.
来源：https://stackoverflow.com/questions/3008958/datagridview-retains-waitcursor-when-updated-from-thread