Windows Forms ToolTip will not re-appear after first use

Question

I have a Windows Forms C# application where I would like to use a tooltip on one of the text boxes. I initialize the tool-tip in the constructor of the Form class, and it works the first time. So when I hover over the text box with my mouse it works, but once the toolTip times out and it goes away, it does not re-appear when I move my mouse away and back onto the control. I would expect it to come back. What am I doing wrong?

Here is how I initialize the tooltip:

myTip = new ToolTip(); myTip.ToolTipIcon = ToolTipIcon.Info; myTip.IsBalloon = true; myTip.ShowAlways = true;  myTip.SetToolTip(txtMyTextBox,"My Tooltip Text"); 

Answer 1

I had a similar problem today. Sometimes, the tooltip would not show. I had one ToolTip control for all the controls in my form.

I also had a MouseEnter event on all the controls added automatically, so I modified the MouseEnter event to do:

_tooltip.Active = false; _tooltip.Active = true; 

It fixed the bug, but I don't know why.

Also, the bug always happened on Windows XP machines, but not on Windows Vista.

Answer 2

I guess you'll be happy to know that Microsoft knows about it...since about 5 years...

• 2/21/2005 Bug acknowledged as reproducable
• 3/29/2005 Hum we might fix it, but later...
• 11/15/2005 Well actually it's not a big bug, and it doesn't happen much, so we won't fix it.

Damn I love it when I stumble on bugs Microsoft doesn't want to solve! This time it's called a corner case, last time it was simply too difficult to resolve...

http://connect.microsoft.com/VisualStudio/feedback/details/115385/tooltip-stop-showing-after-autopopdelay

I'm off to tell my client that the bugs in my program are just corner cases and too difficult to resolve...