Mouse cursor disappears when textbox at ToolStripDropDown editing

Question

I have a user control with RichTextBox and two buttons on it. I'm trying to show that at ToolStripDropDown on ToolStripButton click. I'm using ToolStripControlHost to put my control at ToolStripDrowDown. When I click ToolStripButton at form toolbar, I show dropdown at some position and make focus at ToolStripControlHost control. Mouse pointer stays above ToolStripButton and cursor is at RichTextBox. But when I start editing RichTextBox mouse pointer disappears and I can see it only when it's out of form rectangle. How can I fix it?

Here is my code:

private void toolBtnNote_Click(object sender, EventArgs e)
{

   dropDownClosed = false;
   noteChanged = false;

   tsdd = new ToolStripDropDown();
   this.tsdd.Opened += new EventHandler(tsdd_Opened);
   this.tsdd.AutoSize = true;

   NoteEdit ne = new NoteEdit();
   ne.NoteText = note ?? "";
   // appears when user clicks first button at my control
   ne.OkClick += new NoteEdit.NoteEditEvent(ne_OkClick);
   // appears when user clicks second button at my control
   ne.CancelClick += new NoteEdit.NoteEditEvent(ne_CancelClick);

   this.tbh = new ToolStripControlHost(ne, "noteEdit");
   this.tbh.Padding = new Padding(0);
   this.tbh.AutoSize = false;
   this.tbh.Size = ne.Size;

   this.tsdd.Items.Add(tbh);
   this.tsdd.Padding = new Padding(0);
   this.tsdd.Closing += new ToolStripDropDownClosingEventHandler(tsdd_Closing);
   // show toolstripdrowdown at specific position at DataGridView         
   this.tsdd.Show(dgvMarks, cellRect.Location + new Size(0, cellRect.Height));

   while (!this.dropDownClosed)
   {
       Application.DoEvents();
   }

   if(noteChanged) {...}
}

void ne_CancelClick()
{
    tsdd.Close();
}

void ne_OkClick()
{
    noteChanged = true;
    tsdd.Close();
}

void tsdd_Opened(object sender, EventArgs e)
{
    tbh.Focus();
}

void tsdd_Closing(object sender, ToolStripDropDownClosingEventArgs e)
{
    dropDownClosed = true;
}

Answer 1

I found the solution. Not best but it works. I just simulate click at shown RichTextBox with WinApi like that:

public class WinApiHelper
{
    private const UInt32 MOUSEEVENTF_LEFTDOWN = 0x0002;
    private const UInt32 MOUSEEVENTF_LEFTUP = 0x0004;

    [DllImport("user32.dll")]
    private static extern void mouse_event(
        UInt32 dwFlags, // motion and click options
        UInt32 dx, // horizontal position or change
        UInt32 dy, // vertical position or change
        UInt32 dwData, // wheel movement
        IntPtr dwExtraInfo // application-defined information
        );

    public static void SendClick(Point location)
    {
        Cursor.Position = location;
        mouse_event(MOUSEEVENTF_LEFTDOWN, 0, 0, 0, new System.IntPtr());
        mouse_event(MOUSEEVENTF_LEFTUP, 0, 0, 0, new System.IntPtr());
    }     
}

private void toolBtnNote_Click(object sender, EventArgs e)
{
        dropDownClosed = false;
        noteChanged = false;

        dgvMarks.Focus();
        tsdd = new ToolStripDropDown();
        this.tsdd.Opened += new EventHandler(tsdd_Opened);
        this.tsdd.AutoSize = true;

        NoteEdit ne = new NoteEdit();
        ne.NoteText = note ?? "";
        ne.OkClick += new NoteEdit.NoteEditEvent(ne_OkClick);
        ne.CancelClick += new NoteEdit.NoteEditEvent(ne_CancelClick);

        this.tbh = new ToolStripControlHost(ne, "noteEdit");
        this.tbh.Padding = new Padding(0);
        this.tbh.AutoSize = false;
        this.tbh.Size = ne.Size;

        this.tsdd.Items.Add(tbh);
        this.tsdd.Padding = new Padding(0);
        this.tsdd.Closing += new ToolStripDropDownClosingEventHandler(tsdd_Closing);

        this.tsdd.Show(dgvMarks, cellRect.Location + new Size(0, cellRect.Height));
        // emulate click on richtextbox at dropdown 
        WinApiHelper.SendClick(tsdd.Location + new Size(ne.Rtb.Location) + new Size(5, 5));

        while (!this.dropDownClosed)
        {
            Application.DoEvents();
        }

        if (noteChanged)
        {...}
 }

Answer 2

It is normal behavior for the mouse cursor to hide when you start to edit a TextBox, or RichTextBox. It should be restored when you move the mouse. You should also note that calling Cursor.Show will not have an effect if you try to call it in TextChanged, or something similar.