WPF TemplateBinding vs RelativeSource TemplatedParent

Question

What is the difference between these 2 bindings:

<ControlTemplate TargetType="{x:Type Button}">
   <Border BorderBrush="{TemplateBinding Property=Background}">
      <ContentPresenter />
   </Border>
</ControlTemplate>

and

<ControlTemplate TargetType="{x:Type Button}">
   <Border BorderBrush="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Background}">
      <ContentPresenter />
   </Border>
</ControlTemplate>

?

if you need TwoWay Binding, you gotta use the second option – Joachim Kerschbaumer Sep 23 '11 at 07:01 — Joachim Kerschbaumer, Sep 23 '11 at 07:01

score 215 · Accepted Answer · answered Dec 01 '09 at 01:52

215

TemplateBinding is not quite the same thing. MSDN docs are often written by people that have to quiz monosyllabic SDEs about software features, so the nuances are not quite right.

TemplateBindings are evaluated at compile time against the type specified in the control template. This allows for much faster instantiation of compiled templates. Just fumble the name in a templatebinding and you'll see that the compiler will flag it.

The binding markup is resolved at runtime. While slower to execute, the binding will resolve property names that are not visible on the type declared by the template. By slower, I'll point out that its kind of relative since the binding operation takes very little of the application's cpu. If you were blasting control templates around at high speed you might notice it.

As a matter of practice use the TemplateBinding when you can but don't fear the Binding.

answered Dec 01 '09 at 01:52

Grant BlahaErath

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So the main think to remember: Compile time vs Runtime. The TemplateBinding won't work if you try it to change during the runtime. Right ? – theSpyCry Feb 18 '10 at 07:29
3

Also note that using Binding instead of TemplateBinding can have implications as to what you see during Design Time. In certain configurations, properties that are bound using {Binding RelativeSource...} won't appear in the designer (though they still show up during run time), but if you switch to using {TemplateBinding...} those properties are evaluated during Design Time. – lfalin Nov 12 '14 at 00:15
1

One thing I'll add in case it helps future visitors is that because TemplateBinding is evaluated at compile time you cannot use TemplateBinding to bind to a user defined attached property. In the case of user defined attached properties, you must use "{Binding RelativeSource={RelativeSource TemplatedParent} ... }" – MNB Mar 18 '20 at 18:59

score 38 · Answer 2 · answered Feb 27 '12 at 05:47

TemplateBinding - More limiting than using regular Binding

More efficient than a Binding but it has less functionality
Only works inside a ControlTemplate's visual tree
Doesn't work with properties on Freezables
Doesn't work within a ControlTemplate's Trigger
Provides a shortcut in setting properties(not as verbose),e.g. {TemplateBinding targetProperty}

Regular Binding - Does not have above limitations of TemplateBinding

Respects Parent Properties
Resets Target Values to clear out any explicitly set values
Example: <Ellipse Fill="{Binding RelativeSource={RelativeSource TemplatedParent},Path=Background}"/>

score 24 · Answer 3 · answered May 24 '11 at 16:39

24

One more thing - TemplateBindings don't allow value converting. They don't allow you to pass a Converter and don't automatically convert int to string for example (which is normal for a Binding).

answered May 24 '11 at 16:39

Miroslav Nedyalkov

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Thanks Miroslav, this was the problem I was encountering, switching to using TemplatedParent solved the problem. – MikeKulls Jul 04 '11 at 23:46

score 17 · Answer 4 · edited Jul 10 '15 at 08:04

17

TemplateBinding is a shorthand for Binding with TemplatedParent but it does not expose all the capabilities of the Binding class, for example you can't control Binding.Mode from TemplateBinding.

edited Jul 10 '15 at 08:04

Nikhil Agrawal

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answered Jul 15 '09 at 19:16

Nir

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score 1 · Answer 5 · answered Jan 20 '10 at 14:41

1

I thought TemplateBinding does not support Freezable types (which includes brush objects). To get around the problem. One can make use of TemplatedParent

answered Jan 20 '10 at 14:41

Yaz

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David Rogers · Answer 6 · 2011-09-09T17:38:44.797

0

They are used in a similar way but they have a few differences. Here is a link to the TemplateBinding documentation: http://msdn.microsoft.com/en-us/library/ms742882.aspx

edited Sep 09 '11 at 17:38

answered Jul 15 '09 at 15:56

David Rogers

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WPF TemplateBinding vs RelativeSource TemplatedParent

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