How to align the right edges of a control and tooltips in C #

Question

I want to show the ToolTip message below the TextBox , but also want them to be right-aligned.

I managed to place the ToolTip message on the right edge of the text box, so I tried to move the message to the left of the message length.

So, I tried to get the length of the string using TextRenderer.MeasureText (), but the position is a bit discharged, as shown below.

 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); } 

I tried using different flags in the MeasureText () function, but that did not help, and since the ToolTip message is indented, I went for TextFormatFlags.LeftAndRightPadding.

To be clear, this is what I would like to achieve:

Answer 1

You can set the OwnerDraw property of the ToolTip to true. You can then control the appearance and location of the tooltip in the Draw event. In the following example, I found a tooltip handle and moved it to the desired location using the MoveWindow function of the Windows API:

 [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); } 

Answer 2

The ToolTip font is larger than SystemFonts.DefaultFont, so the measurement is incorrect. I don't know what the exact variable for the ToolTip font is, but many other SystemFonts are set to Segoe UI / size 9, which is the Tooltip font on my PC. In addition, you must add 6px to fill.

 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.CaptionFont, textBox1.Size, TextFormatFlags.LeftAndRightPadding).Width; textWidth += 6; int toolTipTextPosition_X = textBox1.Size.Width - textWidth; myToolTip.Show(test, textBox1, toolTipTextPosition_X, textBox1.Size.Height); } 

For perfect control, you can draw a tooltip yourself using Tooltip.OwnerDraw and the Tooltip.Draw event, choosing a font, padding and appearance.