This is the archived version of Roland Weigelt's weblog that ran from 2003 to 2023 at

ToolTip ToolTip toolTip

While working on a WPF control that handles some aspects of its (optional) tooltip programmatically, I wrote the following lines:

if (ToolTip is ToolTip toolTip)
  // … do something with toolTip …

This makes perfect sense and isn’t confusing inside Visual Studio (because of syntax highlighting), but made me smile nevertheless.


  • The code uses the “is” shorthand introduced in C# 7 that combines testing for “not null” and the desired type with declaring a corresponding variable (I love it!).
  • The first “ToolTip” is the control’s ToolTip property (FrameworkElement.ToolTip), which is of type “object”.
  • The second “ToolTip” is the class “System.Windows.Control.ToolTip”.

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