如何在C#中对齐控件和ToolTip消息的右边缘

Question

我想在a ToolTip下方显示一条消息TextBox,但也希望它们是正确对齐的.

我能够将ToolTip消息放在文本框的右边缘,所以我尝试按消息长度移动消息.

所以我尝试使用TextRenderer.MeasureText()来获取字符串长度,但是位置有点偏,如下所示.

private void button1_Click(object sender, EventArgs e)
{
   ToolTip myToolTip = new ToolTip();

   string test = "This is a test string.";
   int textWidth = TextRenderer.MeasureText(test, SystemFonts.DefaultFont, textBox1.Size, TextFormatFlags.LeftAndRightPadding).Width;
   int toolTipTextPosition_X = textBox1.Size.Width - textWidth;

   myToolTip.Show(test, textBox1, toolTipTextPosition_X, textBox1.Size.Height);
}

我尝试在MeasureText()函数中使用不同的标志,但它没有帮助,因为ToolTip消息有填充,我去了TextFormatFlags.LeftAndRightPadding.

要清楚,这就是我想要实现的目标:

Answer 1

您可以将的OwnerDraw属性设置ToolTip为true。然后您可以控制工具提示的外观和位置Draw。在以下示例中，我找到了工具提示句柄，并使用MoveWindowWindows API函数将其移至所需位置：

[System.Runtime.InteropServices.DllImport("User32.dll")]
static extern bool MoveWindow(IntPtr h, int x, int y, int width, int height, bool redraw);
private void toolTip1_Draw(object sender, DrawToolTipEventArgs e)
{
    e.DrawBackground();
    e.DrawBorder();
    e.DrawText();
    var t = (ToolTip)sender;
    var h = t.GetType().GetProperty("Handle",
      System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
    var handle = (IntPtr)h.GetValue(t);
    var c = e.AssociatedControl;
    var location = c.Parent.PointToScreen(new Point(c.Right - e.Bounds.Width, c.Bottom));
    MoveWindow(handle, location.X, location.Y, e.Bounds.Width, e.Bounds.Height, false);
}