I'm not very clear of when to use a CustomControl and when to use an UserControl. I basically know what CustomControl allow(more customization when using with template).
I want to make a "File browse" control in WPF(TextBlock that displays the current path + Button that trigger a "Open File Dialog").
I'm not sure, because at some places I find that they say this should always "replace" a WPF control. I was more thinking that a a CustomControl was more like a way to display and edit one new semantic value (in my case, a "File(path)").
So, if we don't take into account which one is easier to do, what would be the more adequate between CustomControl and UserControl for the "FileBrowse" control that I'm speaking about?
Thank you
Custom Control:
A loosely coupled control w.r.t code and UI
Derives from Control
Defines UI in a ResourceDictionary
UI can be changed in different projects
Has full toolbox support
Defines a single control
More flexible
User Control :
A tightly coupled control w.r.t code and UI
Derives from UserControl
Defines UI as normal XAML
UI is fixed and can't have different looks in different project
Can't be added to the toolbox
Defines a set of controls
Not very flexible like a Custom Control
When we talk about differences, it is more important to emphasis on the context when to use what:
When you have a rapid and fixed content in your UI, use UserControl.
When you want to separate some basic functionality of your main view to some smaller pieces with reusability, use UserControl.
When you want to use your control in different projects and each project may want to change the look, use CustomControl.
When you want to implement some additional functionality for a control, create a CustomControl derived from the base control.
When you want to apply themes to your controls, use CustomControl.
When you want to add toolbox support for your control, so that your user will be able to do drag and drop to the designer, use CustomControl.
I think a UserControl is the one to choose, for it is used for a kind of "assembly of existing controls". In your case a button and a file open dialog. It will then get a specific look and feel (for example the default look of a button and the default look of a file open dialog).
The CustomControl is kind of the other way round. It has no look and feel by itself. It is completely abstract concerning layout. The layout comes into play, wwhen assigning a style to it.
In general a custom control extends an existing control while a user control creates a new control type from a collection of existing controls. I would say that a user control is better suited, based on the information you've given.
I've been reading some explanations about the difference between User and Custom Controls, for example this:
http://www.wpftutorial.net/CustomVsUserControl.html
I want to create, for example, a simple composition of a datagrid with 2 comboboxes which are responsible to change the values from the datagrid's items. I want to create a specific control for this because I'm going to use it a lot of times. I would like to implement the logic behind and then in the xaml invocation I only have to specify the itemsSource.
For this example should I create a User or Custom control? Since I will have properties and logic, should I have a viewmodel for this control?
EDIT: Do you know some articles with clear conceptual separation between these 2 options?
Choice is not only between user control and custom control, but among user control, custom control, customizing control template, customizing data template, header template (for collection based controls), attached properties.
Refer to Control Authoring overview
I go by following order of consideration
Attached Properties : If functionality can be achieved, I use attached properties. Example, Numeric text box.
Control Template : When requirement can be fulfilled by customizing the control template, I use this. Example, circular progress bar.
Custom control: If control template cannot do it, I use custom control. Provided I need to customize/extend already present control. Example providing Sorting, Filtering based on header row in GridView (GridView is present in metro apps, used just to illustrate the example)
User control: Least preferred one. Only when composition is required, and I am unable to do it using custom control. Like in your example, 2 Combobox, and 1 datagrid. User controls does not provide seamless lookless feature that can be leveraged through custom control or control template.
You already have some great answers that explain the differences but also understand that custom controls and UserControls have different purposes:
A UserControl typically encapusulates some sort of composite behaviour. If you have an application that needs to edit contact details in many places, for example, you could create a custom control that has the labels and text fields for all the data laid out with a submit button that has the relevant code and reuse this control throughout your application.
A custom control is a control that is derived from one of the WPF control classes (E.G. Control, ContentControl etc.) and has to be created in code.
These control usually have a single cohesive purpose (think TextBox, ComboBox, Label) rather than acting together as a whole (although this doesn't have to be the case).
UserControl's are usually easier for people unfamiliar with WPF as they can be visually designed.
My suggestion would be to start off with a UserControl. You can always refactor this into a custom control at a later date as you become more familiar with the way WPF works. Creating your control as a custom control will require knowledge of ControlTemplates and Styles as you will need to provide your own to define a look and feel for your control.
When all is said and done, as long as the control behaves correctly, it doesn't matter which approach you use.
See this post for an example of two approaches to the same problem. The post author wanted a control which can present modal content in front of the primary content. The post author actually answered his own question by implementing it as a UserControl. I have added an answer to the post which creates the control as a custom control but both have the same end effect.
If you have a view-model and you wish to create a view for it use the User-Control.
If you need an autonomous control that has no specific view-model,
you probably need a custom-control.
If you find that the functionality you need as whole, already exist in other controls you need to override an existing control template.
(i.e: for a diamond shaped button - you need to override the button control template.)
Regarding attached-properties and attached-behaviors, those are useful when you have a control which you want to extend with more properties or you want it to behave slightly different than its default behavior.
In the provided case of the composition the OP described, it can be achieved with either user control or custom control. I would prefer a custom control since there is no specific view model provided, the "input" is only a property bound to an item collection.
Oh, and, I am sorry for slightly being late.
The best explanation is in the msdn. CustomControl is more a "virtual" name, there is no class called "CustomControl" in WPF, instead its meant creating a new class building on top of one of WPF control classes, like Control, ItemsControl and even more specific Controls like TextBox or Button.
For your specific case, a UserControl should be enough, creating a CustomControl is something that can easily be avoided. While its not a bad thing, a lot of people, especially beginners in WPF coming from WinForms tend to subclass more then necessary.
If this is somehow your first time building controls, I recommend UserControl as VS lets you design its interface more easily. Custom Controls are more powerful, but you have to CLEARLY separate your control's logic from its interface and this requires a bit more preparation.
You can easily Visually design CustomControl.
Create new UserControl (or Window). Create its xaml structure visually in Designer. Copy-paste body of the resulting xaml inside ControlTemplate of your new CustomControl (Eg. in generic theme file).
If I remember right, you are also able to visually design CustomControl template directly, in Blend.
Of course you can also instance the wip CustomControl in a Window and put the Window's Designer view as new panel above the control's xaml view in VisualStudio.
Some xaml bindings from style template don't show in Designer like this though, until I rebuild.
[ Imho GUI is mainly a visual matter and should not, and doesn't need to, be created in code. ]
Well to create a Custom control you need to implement it as a User control. Your own User control is called a Custom control. It is pretty simple.
UserControl is the base class for containing your custom content :
<UserControl>
Your custom WPF content
</UserControl>
I don't totally agree with the article. However in your case you need a UserControl that you can re-use latter in your UI.
I am aiming at creating different UserControls for my college project, in which I am attempting to use ContentControl to wrap my UserControl. I've placed other Controls like Image, WebBrowser, MediaElement and the like, now I have reached a stage where I need to set the properties for my UserControls. Thus, I thought of making use of PropertyGrid Control, but now the problem I am facing is in the PropertyGrid control, as I get all the default properties of the Controls, which in my case I don't want.
For Eg: if I use Image Control then i need properties like Source and Stretch to be displayed only in the PropertyGrid. Can anyone help me in achieving this?
I tried to override some default properties like "Name" and assign it as [Browsable(false)] to hide it from being displayed. I don't want to do this for all the other properties which are being displayed and which are not under my requirements as well.
I am using Xceed.Wpf.Toolkit for my PropertyGrid.
It is explained in the documentation on how to do that:
http://wpftoolkit.codeplex.com/wikipage?title=PropertyGrid
When you change the selected object see SelectedObjectType and set PropertyDefinitions in code to match the properties you want to see for that type of object.
I've searched the web for some introductory tutorial about the Extended WPF Toolkit PropertyGrid (http://wpftoolkit.codeplex.com) and custom attributes but didn't find. I've also downloaded the source code with the samples inside but that didn't help either. I'm a beginner with WPF so i might be missing something simple here. What i want to do is to create a simple Property Grid with some custom attributes. Does someone have a code snippet of something simple like a Property Grid with two attributes like Name and Age that are associated with some class like Person. I've already tried the snippet that they provide in the PropertyGrid documentation page on Codeplex but i couldn't get it to work. I've managed to put the Property Grid appear on the UI, but that's all, no custom attributes.
And your Name, Age are string/int types.. So if you assign your object as SelectedObject to PropertyGrid- it must do just fine. For example here is my code where i show application settings as property grid to the user:
wpf:
<extToolkit:PropertyGrid
Name="PropertyPanel"
IsManipulationEnabled="True"></extToolkit:PropertyGrid>
codebehind:
PropertyPanel.SelectedObject = Properties.Settings.Default;
PopertyGrid assigns templates automatically, depending on property type.
I'm on a project where we use MVVM pattern.
By user layout: Sorting order of a grid, state of window or control.
For example is it possible to serialize all WPF control layout?
AvalonDock can serialize its layout, but that won't apply for grid column widths (AvalonDock is by all means great library!).
Also, I have written a set of classes that can make any property (of serializable type) of any object (in an WPF application) persistent only via adding a [Configurable] attribute to the property. It shouldn't be hard to customize it to save the properties based on a different criterion than presence of an attribute. But it saves the values on per-type basis, so it might be something else than you are looking for.
I can share if you wish.