Yet another blog about WPF, Surface, SL, MVVM, NUI.... - Tag - how-to

[UPDATED] How to call the method from the base of the base of the current class ? (base.base.MyMethod)

2011-05-11T23:56:00+02:00

Today I encountered a tricky need in some custom control. It was inheriting from the TabControl but I didn’t want all its feature. Especially I didn’t want it to update the SelectedContent dependency property because it was keeping a strong reference to a ViewModel and keeping it away from the garbage collector.

The problem is that the TabControl do this in an event handler of the ItemContainerGenerator’s StatusChanged event. This subscription is made in the OnInitialized method. This one is marked as protected and virtual so I could override it to do nothing but if had do so I would have loose all the work done in the base class of the TabControl which... Read [UPDATED] How to call the method from the base of the base of the current class ? (base.base.MyMethod)

[RIA Services] Why the client extended entities won't use the default backing store value ? EDITED

2010-11-19T16:13:00+01:00

The title may not be clear but I am talking about the entities that you extends on the client side using the fact that they are partial class. You may think as I was that if you add properties in them with backing store field, the properties will get initialed nicely : this is not the case and the property will always use the default value for the... Read [RIA Services] Why the client extended entities won't use the default backing store value ? EDITED

VS Tip : how to locate the active document in the solution explorer using a shortcut

2010-11-04T12:39:00+01:00

When you have multiple projects in your solution, you often want to locate the active document in the solution explorer. There is a great option in Visual Studio which can do it for you all the time : “View.TrackActivityInSolutionExplorer”. But if you do not want (as me) to turn it on all the time, there is no specific option or shortcut. So I... Read VS Tip : how to locate the active document in the solution explorer using a shortcut

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

2010-10-25T00:01:00+02:00

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)

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

2010-10-03T23:27:00+02:00

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)

WPF tip : How can I use static/dynamic resources in my tests

2010-09-24T12:33:00+02:00

You are surely, as I am, creating a lot of units tests in your WPF applications. Some of the tests may use statics or dynamics resources declared in your application and when you launch the tests, all you get is an XamlParseException exception thrown. System.Windows.Markup.XamlParseException: 'Provide value on... Read WPF tip : How can I use static/dynamic resources in my tests

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

2010-09-14T22:42:00+02:00

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

2010-06-16T15:07:00+02:00

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)

2010-06-13T12:03:00+02:00

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

2010-04-27T23:52:00+02:00

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

2010-04-12T22:53:00+02:00

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 !

2010-04-08T23:14:00+02:00

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 !

Binding on a Property which is not a DependencyProperty

2010-04-05T09:03:00+02:00

A lot of controls expose properties which are not DependencyProperties and then you can’t put a binding on it. On some other cases, you only have a getter as accessor and you can’t put a binding on it too… This is for example the case for the ribbon’s group of the office ribbon or the converter’s parameter. If you ever tried to do so, you... Read Binding on a Property which is not a DependencyProperty

MVVM - Creating ViewModel tutorial

2010-03-11T11:58:00+01:00

MVVM - Creating ViewModel is a serie of blogposts that talk in details about various ways to create a ViewModel to use it with the MVVM pattern. You often do not create the business object used by the application which are created by another team and that these objects are not ready for binding. So you must find a solution to create an object... Read MVVM - Creating ViewModel tutorial

Sync framework - choose your primary keys type carefully

2010-03-05T00:44:00+01:00

Do you know the Sync Framework ? This is an amazing framework that enables roaming, sharing of data, and taking data offline ! One usage You can imagine is to sync some local clients databases with a big distant one. Each client taking its data with him and each client was abble to edit/create/delete data. The scenarii where the problem... Read Sync framework - choose your primary keys type carefully

MVVM - How to integrate the Office Ribbon respecting the pattern (especially the commands)

2010-03-04T20:01:00+01:00

Synopsis The ribbon controls - introduced by office 2007 -are available for free on the Microsoft Office web site (French users should set the language to "english" to access the ressources). They can leverage the user's experience of your application and are pretty simple to use. When I wanted to add them into one of my application I realized... Read MVVM - How to integrate the Office Ribbon respecting the pattern (especially the commands)

MVVM : How to keep collections of ViewModel and Model in sync

2010-03-02T12:31:00+01:00

As pointed out in this post collections of the ViewModels and the models are not sync. This is because we do not access directly to the model but to an ObservableCollection(in the viewModel) which contains the object of the original collection(in the model) and that these two collections are not the same... As pointed out in the comments on... Read MVVM : How to keep collections of ViewModel and Model in sync

WPF - catch events even if they are already handled

2010-02-19T19:04:00+01:00

As you may actually know WPF introduced the routed events. These last are no more specific to a single control but they are routed inside the tree of your controls. If you want to stop an event, you can mark it as Handled. If so, the routing engine will stop to propage it. In fact this is just an illusion because the engine will only stop... Read WPF - catch events even if they are already handled

Use AttachedProperties to add behaviors to the components (Ramora pattern)

2010-02-19T17:47:00+01:00

The problem In WPF you expect your components/controls to behave exactly as you want to.... but this not always the case. For example : why does this combobox not execute a command when I change the selection or more often why this textbox does not execute a command when I press the Enter (return) key ? This problem often occurs when you use... Read Use AttachedProperties to add behaviors to the components (Ramora pattern)

CREATE, LAUNCH and CONTROL a WPF animation FROM CODE

2009-07-07T14:30:00+02:00

The problem Sometimes you need to animate your specific object and for this purpose there is the WPF animation. Here are the prerequireds : The property you want to animate must be a DependencyProperty, The property must so be a part of a DependencyObject, Your object must implement IAnimatable to be able to launch the animation. The... Read CREATE, LAUNCH and CONTROL a WPF animation FROM CODE