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Asked: 2020-01-02 14:37:43 +0800 CST 2020-01-02 14:37:43 +0800 CST

Show control on mouse input

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I have a TextBoxand I want that while the mouse is over the control, a will appear Buttonon the right side, above the TextBox. The fact is that the TextBoxalso has a custom behavior, so both controls are embedded in a custom control that inherits from UserControl. All of this, of course, using WinForms.

The first thing that occurred to me is to handle the events MouseEnterand MouseLeaveas shown below:

public partial class MiControl : UserControl
{
  void textBox_MouseEnter(object sender, EventArgs e)
  {
    boton.Visible = true;
  }

  void textBox_MouseLeave(object sender, EventArgs e)
  {
    boton.Visible = false;
  }
}

This option works fine until the mouse hovers over the Button. At that moment both events begin to alternate uncontrollably and the only visible effect is that the button cannot be pressed. The truth is that it makes all the sense in the world: if the mouse hovers over it, Buttontechnically it is leaving the TextBox, so the event is fired MouseLeave. The latter causes the mouse to become inside the TextBox, which triggers the event MouseEnterand starts over.

How could I control this situation?

c#

1 Answers

  1. Best Answer

    When the event is fired MouseLeave, check if the mouse is still over the TextBoxusing the ClientRectangledel property TextBoxand the (static) property Control.MousePositionas follows:

    if(!textBox.ClientRectangle.Contains(textBox.PointToClient(Control.MousePosition)))
  boton.Visible = false;

    To make sure the button is hidden when the mouse is released, also run this update when the event MouseLeavefor the button is fired:

        void textBox_MouseLeave(object sender, EventArgs e)
    {
        ActualizarVisibilidad();
    }

    void boton_MouseLeave(object sender, EventArgs e)
    {
        ActualizarVisibilidad();
    }

    void ActualizarVisibilidad()
    {
        boton.Visible = textBox.ClientRectangle.Contains(textBox.PointToClient(Control.MousePosition));
    }
    • 2