学步园

bool IsShown = false;      

        void Form1_MouseMove(object sender, MouseEventArgs e)
        {
           Control ctrl = this.GetChildAtPoint(e.Location);

           if (ctrl != null)
           {
               if (ctrl == this.button1 && !IsShown)
               {
                   string tipstring = this.toolTip1.GetToolTip(this.button1);                 
                   this.toolTip1.Show(tipstring, this.button1, this.button1.Width /2, this.button1.Height / 2);
                   IsShown = true;
               }
           }
           else
           {
               this.toolTip1.Hide(this.button1);
               IsShown = false;
           }
        }    
以上的TextBox是在form上是可以用这个的。

如果textBox在GroupBox或Panel上则不能用以上的代码了。

就得把TextBox的ReadOnly=true然后在TextBox_MouseMove()中写入如下代码

private void textBox1_MouseMove(object sender, MouseEventArgs e)
        {                                 
             string tipstring = this.toolTip1.GetToolTip(this.textBox1);
             this.toolTip1.Show(tipstring, this.textBox1, this.textBox1.Width / 2, this.textBox1.Height / 2);
           
        }

//离开鼠标的的事件

        private void textBox1_MouseLeave(object sender, EventArgs e)
        {
            this.toolTip1.Hide(this.textBox1);
        }