Displaying tooltip on mouse hover of a text

Question

I want to display a tooltip when the mouse hovers over a link in my custom rich edit control. Consider the following text:

We all sleep

Answer 1

You shouldn't use the control private tooltip, but the form one. This example works well:

public partial class Form1 : Form
{
    private System.Windows.Forms.ToolTip toolTip1;

    public Form1()
    {
        InitializeComponent();
        this.components = new System.ComponentModel.Container();
        this.toolTip1 = new System.Windows.Forms.ToolTip(this.components);

        MyRitchTextBox myRTB = new MyRitchTextBox();
        this.Controls.Add(myRTB);

        myRTB.Location = new Point(10, 10);
        myRTB.MouseEnter += new EventHandler(myRTB_MouseEnter);
        myRTB.MouseLeave += new EventHandler(myRTB_MouseLeave);
    }


    void myRTB_MouseEnter(object sender, EventArgs e)
    {
        MyRitchTextBox rtb = (sender as MyRitchTextBox);
        if (rtb != null)
        {
            this.toolTip1.Show("Hello!!!", rtb);
        }
    }

    void myRTB_MouseLeave(object sender, EventArgs e)
    {
        MyRitchTextBox rtb = (sender as MyRitchTextBox);
        if (rtb != null)
        {
            this.toolTip1.Hide(rtb);
        }
    }


    public class MyRitchTextBox : RichTextBox
    {
    }

}