Maximum number of lines for a Wrap TextBlock

Question

I have a TextBlock with the following setting:

TextWrapping="Wrap"

Can I determine the maximum number of lines?

for example consider the following string TextBlock.Text:

This is a very good horse under the blackboard!!

It currently has been shows like this:

This is a very 
good horse under 
the blackboard!!

I need that to become something like:

This is a very 
good horse ...

any solution?

Answer 1

Update (for UWP)

In UWP Apps you don't need this and can use the TextBlock property MaxLines (see MSDN)

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Original Answer:

If you have a specific LineHeight you can calculate the maximum height for the TextBlock.

Example:

TextBlock with maximum 3 lines

<TextBlock 
  Width="300"
  TextWrapping="Wrap" 
  TextTrimming="WordEllipsis" 
  FontSize="24" 
  LineStackingStrategy="BlockLineHeight"
  LineHeight="28"
  MaxHeight="84">YOUR TEXT</TextBlock>

This is all that you need to get your requirement working.

How to do this dynamically?

Just create a new control in C#/VB.NET that extends TextBlock and give it a new DependencyProperty int MaxLines.
Then override the OnApplyTemplate() method and set the MaxHeight based on the LineHeight * MaxLines.

That's just a basic explanation on how you could solve this problem!