Yet another blog about WPF, Surface, SL, MVVM, NUI.... - Tag - Windows Presentation Foundation

What ? Dynamic resources creates Memory leaks in WPF 3.5 (SP1) ???

JonathanANTOINE@falsemail.com — Sun, 27 Mar 2011 08:12:00 +0200

Everyone is told to not use DynamicResource during its childhood in WPF-(wonder)land. They are simply evil and they kill the app performance. Sometimes, we fall in the dark side of the force and use them effectively to be sure that the application will follow the trend and suits itself well. This is not as bad as it seems and it is in fact sometimes necessary and wanted.

But today, while I was trying to improve the performance and the memory usage of a WPF application I work on, I discovered that they were also creating memory leaks! I felt betrayed. I was using them and they put a knife in my back while I trusted them to be useful.

In this post we will see how it can happens, and how to solve this (little) issue.

I was not alone in this situation and I found out that there were both a work-around and an hotfix available. Here is the information I gathered. Description of the problem When you create and load a ResourceDictionary, the objects you add inside are actually not created immediately. They are referenced in the form of an instance of an object... Read What ? Dynamic resources creates Memory leaks in WPF 3.5 (SP1) ???

UIAutomation, Coded UI tests, AutomationPeer and WPF/silverlight custom controls

JonathanANTOINE@falsemail.com — Thu, 24 Mar 2011 00:04:00 +0100

The Coded UI Tests, available in Visual Studio Ultimate or Premium, enable the creation of automated tests for the User Interface. This is a really nice feature because you are no more forced to make "hand made" tests which takes hours to be performed.

The WPF controls in the framework are ready to be used by the Microsoft UI Automation which is itself used by the coded UI tests. This means that when you use the screen recorder to record the tests on your UI, it will be able to find the several control used in your application.

When you create you own custom controls or extend standard one, the recorder would not be able to find them at first and so a whole part of the screen may not be available for tests. Actually, it is possible to record a test but every steps will be done using screen position: click at (120,30), drag from (120,30) to (10,40). This is really annoying because any changes in the UI may broke all your tests.

In this post, we will see how to make a custom control fully useable in Coded UI tests scenarii. We will so answer the question "Why cannot the code UI test recorder find anything inside my WPF or Silverlight custom control ?"

Note: the same technique is used by the accessibility clients and by enabling this feature you also ease the people using your application through UI automation client like the partially-sighted person.

How it works Everything is based on a class named AutomationPeer. When an UI Automation client analyzes your User Interface, it looks for an automation peer and uses it to walks trough the tree of peers. The tree of peers is nearly a visual tree but it exposes only the relevant part of the interface. Every standard controls have a regarding... Read UIAutomation, Coded UI tests, AutomationPeer and WPF/silverlight custom controls

Introducing the amazing WPF controls library on Codeplex !

JonathanANTOINE@falsemail.com — Mon, 25 Oct 2010 01:19:00 +0200

Hello everyone, I am pleased to announce you the creation of the Amazing WPF controls library on Codeplex ! It will contains the differents controls I describe and/or peel on this blog. I will try to make an article for each control added to the library. Here is a list of the currently available controls : An headered control (the one... Read Introducing the amazing WPF controls library on Codeplex !

How to create an hand writing to text control (ink recognizer)

JonathanANTOINE@falsemail.com — Mon, 25 Oct 2010 00:01:00 +0200

When building a (multi)touch application you may need one nice feature : translate hand-written text to real words. This open a whole new world full of possibilities like starting some actions when keywords are recognized or simply allow the users to write some text for later use.

In this post we'll see all the step to create an hand writing to text control and how to tune it.

Specifications The HandWritingToText controls translate the text written with it's hand by the user into "computer text". The final purpose is to triggers some actions when a specific keyword is recognized and it'll so be able to recognize only one word at a time and not a whole text. The recognized text will be published via an event and... Read How to create an hand writing to text control (ink recognizer)

Migrate the Jetpack theme from Silverlight to WPF

JonathanANTOINE@falsemail.com — Thu, 14 Oct 2010 12:54:00 +0200

There is a great theme named Jetpack available for Silverlight applications which can be found on the Tim Heuer web site. I was wondering if it can be used in WPF applications and the answer is yes ! Here are the modifications I had to do to make all this work : SelectionBackground replace by SelectionBrush (except for the DatePicker) I... Read Migrate the Jetpack theme from Silverlight to WPF

How to create your own control library (how-to + tips)

JonathanANTOINE@falsemail.com — Sun, 03 Oct 2010 23:27:00 +0200

Reusability and factorizing are maybe the most commons things you want and use when you are developing applications. In WPF it often means creating controls library (i don’t mean UserControl) that will be easy to use in multiple applications. In this post we'll see all the step to create a control library useable in differents projects. The... Read How to create your own control library (how-to + tips)

How to create an animated expander

JonathanANTOINE@falsemail.com — Tue, 21 Sep 2010 14:02:00 +0200

The expander control can be used in a lot of situations but the one proposed by default is quite "rigid". In this post we will discover how to animate it quite simply just via XAML ! The WPF engine lets us redefine the template of the controls and we'll just do that. The goal aimed What we aim is to get the same functionnality as the... Read How to create an animated expander

UserControl/Control : how to get a reference to an element of the template

JonathanANTOINE@falsemail.com — Tue, 14 Sep 2010 22:42:00 +0200

When you want to create your own custom control you have two choices : create an UserControl or inherit from one of the "Control's classes" (ContentControl, ItemsControls or Control itself). When doing so, you'll surely need to access to the visual parts of your template from the code to add to it a nice behavior. In this post, we'll discover how... Read UserControl/Control : how to get a reference to an element of the template

Execute a command on a specified control when clicking on a button

JonathanANTOINE@falsemail.com — Wed, 16 Jun 2010 15:07:00 +0200

Today another example of the powerful ramora pattern : execute a RoutedCommand on an Control when you click on a button outside of the aimed control scope. When is it useful ? : for example when you use the infragistics grid (xamdatagrid) and you want to execute the command which remove the selected row from a button outside of the grid. You... Read Execute a command on a specified control when clicking on a button

Binding to the selected items of a ListBox (or an another items controls)

JonathanANTOINE@falsemail.com — Sun, 13 Jun 2010 12:03:00 +0200

A problem you often meet when using MVVM is to get the selected items of an items control, especially Listbox. You can easily bind the selected item or the current items but when multi selection comes in the way, it becomes harder because the SelectedItems (with an 's' property is not available to binding). In this article we will discover an... Read Binding to the selected items of a ListBox (or an another items controls)

[Performance tips] Use the system shadows instead of your own

JonathanANTOINE@falsemail.com — Tue, 27 Apr 2010 23:52:00 +0200

Today a fast and easy tip about shadows and performance. In a project I have recently made, we've told the designer not to use BitmapEffects because they are performance killer. He so decided to create it's own shadows by duplicating each shape and make them looks like shadows(designer magic, voodoo things, etc...). I was then surprised to see... Read [Performance tips] Use the system shadows instead of your own

Freeze brushes directly in the XAML to improve your application's performances

JonathanANTOINE@falsemail.com — Mon, 12 Apr 2010 22:53:00 +0200

When you read the MSDN guidelines to improve WPF's performances you can find that it's a good idea to freeze Freezable objects. It's a quite easy thing to do via the code but it's quite harder to do it directly in the XAML. In this post we will see how to do so. What are freezable objects One upon a time, the MSDN said : A Freezable is a... Read Freeze brushes directly in the XAML to improve your application's performances

Simple properties Mapper by reflection : stop copying manually each property of your objects !

JonathanANTOINE@falsemail.com — Thu, 08 Apr 2010 23:14:00 +0200

There is time when you have to copy each property of an object to one another. This is called mapping and it's very fastidious to do it by hand. In this post we'll see how to create a method extension which do it for you in one line of code ! When can it be useful Here is a non exhaustive list of usage you can find to this snippet: You want... Read Simple properties Mapper by reflection : stop copying manually each property of your objects !