Click here to Skip to main content
Click here to Skip to main content

Tagged as

WPF: TemplateBinding with ControlTemplate

, 7 Jun 2013
Rate this:
Please Sign up or sign in to vote.
A bit on TemplateBinding and how to use it inside a ControlTemplate.

Introduction

Today I'll try to write a bit on TemplateBinding and how to use it inside a ControlTemplate. TemplateBinding is a type of binding used mainly for template scenarios. Here I am not going to write more on its theoretical aspect as what is TemplateBinding, when to use, blah blah blah, as lot of content is readily available on the net.  So, let's start quickly with the coding part:

First of all, let's create a new project using WPF template and place a button in it as below:

Now, what I am going to do is, I am going to replace this content template for this button. So, in order to do this, open up the Button tag and add Button.Template markup tag with a new ControlTemplate as:

Now as soon as you will add ControlTemplate tag, you will notice that the content of the button is gone and button is shown as a transparent rectangle. This has happened because here I told WPF to replace the default ControlTemplate with the one which I defined. But at this point, our ControlTemplate is blank, so there is no visualization and we can see only a transparent rectangle.

Now go ahead and customize our ControlTemplate by putting Ellipse inside it as:

Now we can see that we get a visualization for a button in the form of ellipse. At this point of time, it works OK, but there are scenarios where this struct breaks down.

For example, let's increase the height of button, from 35 to 105 as:

In the above image, you will notice that button height is increased but the ellipse size is still the same, which is a bad UI design. And the reason this is happening is, inside a ControlTemplate, the height of an ellipse is hard coded. So, no matter, whatever height is set at parent (i.e., Button), it will not get inherited to child control (i.e. Ellipse).

So, now we have to fix this problem by using a special type of binding called TemplateBinding inside ControlTemplate. So, instead of hard coding the height, we will use TemplateBinding as shown below:

By setting the TargetType property of ControlTemplate, we are telling Ellipse that, any property of Button can be set to ellipse. Now, whatever the height of button will be, it will automatically be the height of ellipse also. Isn't it interesting?

Moving forward, let's do something more interesting with Fill property of ellipse.

In the above snippet, I am trying to set the Fill property of an ellipse using TemplateBinding. But now the problem here is, a button doesn't have a Fill property. So, there is no one-to-one mapping for Fill property. Now, what to do?

No need to worry that much because button does have a Background property as:

In the above image, you might have noticed that as soon as ellipse's Fill property is set to Background, ellipse becomes transparent as button's background. Now if we set button's Background property to Red, the same will be applied to ellipse too.

So, one can understand how much magic we can do with TemplateBinding.
Now, let's work a little bit on code cleanup.

ControlTemplate Inside Resource Dictionary

For better code readability, we will move out our ControlTemplate code and put it inside a resource dictionary as:

So, now we can see as earlier that whatever visual property for button is set, all get applied to ellipse as well.

Hope this tip was useful and gave you the basic idea on how to use TemplateBinding.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Share

About the Author

Shweta Lodha
Technical Lead
India India
You can also follow me at my blog http://www.shwetalodha.blogspot.in/
Follow on   Twitter

Comments and Discussions

 
QuestionVery good explanation PinmemberMember 46626734-Jul-14 18:30 
AnswerRe: Very good explanation PinpremiumShweta Lodha8-Jul-14 1:00 
GeneralThis is how one should provide a Document PinmemberMember 995663819-Jun-14 1:28 
GeneralRe: This is how one should provide a Document PinpremiumShweta Lodha19-Jun-14 6:08 
Questiongood work PinmemberAnindya00214-Apr-14 4:41 
AnswerRe: good work PinpremiumShweta Lodha14-Apr-14 5:03 
QuestionA BUG??? PinmemberKhalid Akbar8-Apr-14 23:28 
AnswerRe: A BUG??? PinpremiumShweta Lodha9-Apr-14 4:44 
GeneralRe: A BUG??? PinmemberKhalid Akbar12-Apr-14 3:04 
QuestionThanks Pinmembersharmi1728-Mar-14 10:00 
AnswerRe: Thanks PinpremiumShweta Lodha28-Mar-14 16:27 
QuestionThanks A Lot PinmemberJLO201212-Nov-13 22:33 
AnswerRe: Thanks A Lot PinmemberShweta Lodha13-Nov-13 1:18 
GeneralGood Article PinmemberJaganGuruRam6-Nov-13 19:17 
QuestionNot found SetResourceReference in new Groupbox I'm creating in code behind Pinmemberaripian17-Sep-13 21:37 
AnswerRe: Not found SetResourceReference in new Groupbox I'm creating in code behind PinmemberShweta Lodha25-Sep-13 9:11 
GeneralMy vote of 5 Pinmemberaripian11-Sep-13 15:15 
GeneralRe: My vote of 5 PinmemberShweta Lodha25-Sep-13 9:10 
GeneralMy vote of 5 Pinmemberphamchicong28-Aug-13 17:23 
GeneralRe: My vote of 5 PinmemberShweta Lodha29-Aug-13 5:46 
GeneralMy vote of 5 PinmemberPrashant268215-Jul-13 3:03 
GeneralRe: My vote of 5 PinmemberShweta Lodha4-Aug-13 2:19 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.

| Advertise | Privacy | Mobile
Web03 | 2.8.140814.1 | Last Updated 7 Jun 2013
Article Copyright 2013 by Shweta Lodha
Everything else Copyright © CodeProject, 1999-2014
Terms of Service
Layout: fixed | fluid