ToolTip tt;
private void Form1_Load(object sender, EventArgs e)
{
tt=new ToolTip();
}
private void comboBox1_DrawItem(object sender, DrawItemEventArgs e)
{
e.DrawBackground();
e.DrawFocusRectangle();
Rectangle r0 = e.Bounds;
e.Graphics.DrawString(dt.Rows[e.Index]["address"].ToString(), e.Font, new Pen(e.ForeColor).Brush, r0);
Size sz = TextRenderer.MeasureText(dt.Rows[e.Index]["address"].ToString(), e.Font);
if (sz.Width > 80)
tt.Show(dt.Rows[e.Index]["address"].ToString(), comboBox1, r0.X + r0.Width, r0.Y + r0.Height);
else
tt.Hide(comboBox1);
}
private void comboBox1_DropDownClosed(object sender, EventArgs e)
{
tt.Hide(comboBox1);
}