Hourglass problem in a WinForm application

Question

In my program with a UI in WinForm. I set the cursor to a hourglass just before to launch a method in ThreadPool.

My code in UI thread to set the cursor looks like this :

Application.UseWaitCursor = true;

When the method is finished, i go back to the UI Thread to set the cursor to the normal case.

Application.UseWaitCursor = false;

My problem is the cursor stay to the Hourglass till I don't move the mouse. It's a little bit disturbing if the user wait on the end of the action without moving the mouse.

Anyone can help me ?

Jérôme

Sammer

Answer 1

I am unable to reproduce this behaviour? It works fine for me.

One thing to note though if you use the Control.Cursor = Cursors.WaitCursor approach is that it usually used like so:

this.Cursor = Cursors.WaitCursor

Which would appear to work fine, however, this refers the form so if the user moves the mouse to a different control, e.g a TextBox then the mouse does not show the wait cursor.

This may cause confusion for the users. Or could cause some issues if the user continues to work on something else when the Application is busy doing other work.

Ide

Finally I have changed the Cursor Property on the main Form instead of Application.UseWaitCursor and the behavior of my cursor is what I have expected. I have no idea what the problem is coming from... – Sammer

Answer 2

Actually, there is one more way to do it, which I found somewhere after hours of researching this problem.

Unfortunately, it is a hack.

Below is a method that I wrote that handles the problem.

/// <summary>
    /// Call to toggle between the current cursor and the wait cursor
    /// </summary>
    /// <param name="control">The calling control.</param>
    /// <param name="toggleWaitCursorOn">True for wait cursor, false for default.</param>
    public static void UseWaitCursor(this Control control, bool toggleWaitCursorOn)
    {
        ...

        control.UseWaitCursor = toggleWaitCursorOn;

        // Because of a weird quirk in .NET, just setting UseWaitCursor to false does not work
        // until the cursor's position changes. The following line of code fakes that and 
        // effectively forces the cursor to switch back  from the wait cursor to default.
        if (!toggleWaitCursorOn)
            Cursor.Position = Cursor.Position;
    }

Burnett

Thanks for the most useful tip. Actually Cursor.Position = Cursor.Position; was enough for me to add. – Zipangu

You don't need a function for that. Simply write 2 lines: Application.UseWaitCursor = false; Cursor.Position = Cursor.Position; – Colony

Answer 3

One more way:

Cursor.Current = Cursors.WaitCursor;

When finished, just change the cursor back:

Cursor.Current = Cursors.Default;

Dogcart

I am informed that this is the wrong approach: csharp411.com/the-proper-way-to-show-the-wait-cursor – Benitobenjamen

This method worked for me over the Application.UseWaitCursor method. I need to make a wait cursor when I click a button on a tab control. When I set Application.UseWaitCursor or this.UseWaitCursor, the tab.UseWaitCursor property also gets set to true. Then when I do Application.UseWaitCursor = false; the tab.UseWaitCursor remains true! When I get to that tab later, it keeps showing a wait cursor. Not sure why the tab.UseWaitCursor gets set and not cleared, but when I use the Cursor object it seems to work correctly. – Resolved

Answer 4

My solution....

public class SetMouseCursor
{
    public static void Wait()
    {
        Application.UseWaitCursor = true;
        Cursor.Current = Cursors.WaitCursor;
    }

    public static void Default()
    {
        Application.UseWaitCursor = false;
        Cursor.Current = Cursors.Default;
    }
}

Telamon

Answer 5

Set the cursor manually. That's what I do.

Joshia

control.Cursor = Cursors.Busy – Joshia

I think it should be control.Cursor = Cursors.WaitCursor – Ide

@barry: thanks, I couldn't remember, but the idea is still the same :) – Joshia

Answer 6

A reusable solution is to use a little disposable helper class.

public sealed class WaitCursor : IDisposable
{
    public WaitCursor()
    {
        Application.UseWaitCursor = true;
        Cursor.Current = Cursors.WaitCursor;
    }

    public void Dispose()
    {
        Application.UseWaitCursor = false;
        Cursor.Current = Cursors.Default;
    }
}

With C#'s using var usage becomes very easy (example):

using var waitCursor = new WaitCursor();

using var dbContext = new MyDbContext();
await dbContext.Adresses.LoadAsync();
var adresses = _dbContext.Adressen.Local.ToBindingList();
gridControl1.DataSource = adresses;

The default cursor will be restored automatically at the end of the current code block. No need for an explicit try-finally to make the code safe.

User