Custom content control default content - wpf

I have a WPF custom content control inherits from Control and when developer drags this control from toolbox i want it to have a default content like expander control has.
<Expander>
<Grid />
</Expander>
How can i do that ?
Thanks

Instead of inheriting from Control, you'll need to inherit from ContentControl.
Here's a sample blog post showing how this can be done. (The post is using Silverlight, but the technique is identical for WPF.)

Related

Control Template that wraps another control in XAML

I want to create a custom control that extends a built-in control and then has a template that wraps that control with a container?
The C# class:
class ExtraBorderTextBox : TextBox {}
The Xaml:
<ControlTemplate>
<Border>
<TextBox/>
</Border>
</ControlTemplate>
That doesnt' work because the TextBox in the control template isn't my custom control, it is a second instance.
I need access to the properties and events on TextBox, having a different parent doens't make sense, I would have to replicate all of that in my class.
This is a simplified example; imagine Border being replaced with a ContentControl that has a 50 line control template for itself. I guess I want something like ContentPresenter (like I have in the ContentControl), but there isn't anything like a "ControlPresenter". Right? Am I missing something, or am I stuck with replicating my content control for the TextBox, or replicating the TextBox behaviour and presentation for my content control?
Thanks.
Update:
There is an answer here that does what I want, which is to copy the default template for System.Windows.Controls.TextBox. This will do what I want; I can insert my container into that. I was hoping that WPF provided a way that is more maintainable to do something like this, something like a adorner/decorator pattern.
Is there any way to make this better in some way? Would using something like Expression Blend make this so that I don't have to hand-edit the XAML pasted in from the webpage?
You could use the default control template as a base and modify it. The default control templates can be found here: http://msdn.microsoft.com/en-us/library/aa970773.aspx
If I understood you right, you want to inherit from TextBox, do some overriding, and use that new class in XAML.
If so:
1) declare the xmlns namespace at the top of your file:
<UserControl
...
xmlns:local="TheAssemblyWhereExtraBorderTextBoxResides"
...>
2) use your custom textbox:
<ControlTemplate>
<Border>
<local:ExtraBorderTextBox />
</Border>
</ControlTemplate>

Linear navigation in WPF MVVM

I'm using the Cinch MVVM framework, however I think this is something that relates to all WPF approaches.
I want to have a primary screen - Shell or MainWindow - which then contains various viewmodels. To navigate between viewmodels I'm using (or going to use) a tab control styled as a button strip with the content area beneath - which is all ok as I add the viewmodels to the tabcontrol (well to the 'Views' collection which is bound to the tab control) at runtime.
A screen that doesn't fit into this methodology is the sign in screen, which I don't really want to add to the tab control - preferably it should be in it's own usercontrol which takes up the entire screen apart from covering the logo; that is, I would like it to appear in the same window rather than a popup dialog, however I'm not sure how to add/ remove controls dynamically and then add subsequent tabcontrol once the user has signed in successfully (and remove the sign in screen). What containers should be used?
TIA.
The easiest way is put your tabcontrol in a Grid without columns and rows so it fill the grid by default. Then add an extra grid or loginusercontrol to the grid as shown below. The moment a user needs to login you can set the visibility of the MainTabControl" to collapsed and of the LoginGrid to Visible and switch it back after a succesfull login. I hope that the xaml below will help you enough.
<Grid>
<TabControl x:Name="MainTabControl" Visiblity="Visible">
... put your tabs here ...
</TabControl>
<Grid x:Name="LoginGrid" Background="#60FFFFFF" Visibility="Collapsed">
... put your usercontrol to login here or the login controls themself
</Grid>
</Grid>
You could use a ContentControl with content bound to a view model. So you'd have two view-models representing the sign-in screen and the main screen and use DataTemplate to display appropriate screen.
<Window.Resources>
...
<DataTemplate DataType="{x:Type my_view_models:SignInViewModel}">
<my_controls:SignInScreenView />
</DataTemplate>
...
</Window.Resources>
<ContentControl Content={Binding} />
You may be interested by Lakana, it is a lightweight and non intrusive navigation framework for WPF.
Riana

Alternative to "DropDownWidth" Property for Combo Box in wpf

I am unable to locate a property similar to WindowsForm "DropDownWidth" Property for the Combo Box in WPF. Is there a work around to achieve this functionality?
I don't remember if there is such property in a combobox, but you always can alter a default control template. In your case you should specify a width property of a popup element in a control template. Here is a sample code, taken from one of the WPF themes from Codeplex:
<ControlTemplate x:Key="ComboBoxTemplate" TargetType="{x:Type ComboBox}">
...
<Popup ... Width="100" >
...
</ControlTemplate>
This is a general idea. You can look in a themes source code fore more information. This MSDN pages can also be helpful:
Customizing the Appearance of an Existing Control by Creating a ControlTemplate
ComboBox Styles and Templates
Control Styles and Templates

Best practice for dynamically adding controls through copying existent controls in WPF

I have a TabControl.
While clicking a button I want to add a new TabItems to the TabControl.
Among various techniques I've chosen to create UserControl inside of a DockPanel.
Everything works fine, except for the location of control on a new TabItem is not 0 and it is
not expanded on the main form resize.
Everything is quite simple.
<TabItem Header="new control">
<DockPanel LastChildFill="True">
<tc:TabItemTemplate/>
</DockPanel>
</TabItem>
And TabItemTemplate is also located inside a DockPanel, but it's not docked inside a TabItem. What's the catch?
I would suggest using TabControl.ItemTemplate, and bind TabControl.ItemsSource to ObservableCollection of ViewModels. When user clicks on a button, add new View Model instance to the collection. Refer to this article for more details: WPF Apps With The Model-View-ViewModel Design Pattern

Is it possible to create a WPF tab control template that looks nothing like a tab control?

What I'd like is a control that functions just like the tab control but instead of having the tabs along the top, the items would be displayed in a list box along the side. I imagine it's possible but haven't found any examples, I'm hoping there's someone here that's done something like this.
WPF controls are designed to enable exactly what you want. To reuse control functionality while completely replacing the visual representation. You will have to create your own ControlTemplate for the TabControl. You can find a TabControl ControlTemplate Example on MSDN. You will also have to study the Control Authoring Overview on MSDN.
I actually find the Silverlight 3 documentation somewhat easier to digest, and even though there are some differences when it comes to control styling the fundamental concepts are still the same. You can read Customizing the Appearance of an Existing Control by Using a ControlTemplate on MSDN to learn about control templates and then study TabControl Styles and Templates to discover what is required to create you own control template in Silverlight.
You can use Expression Blend to extract the the default TabControl template in WPF.
You don't need to use a TabControl at all. You could just bind your ListBox to a list of items, and put a ContentControl beside it, bound to the selected item :
<DockPanel>
<ListBox Name="listBox"
DockPanel.Dock="Left"
ItemsSource="{Binding Items}"
DisplayMemberPath="Name"/>
<ContentControl Content="{Binding SelectedItem, ElementName=listBox}"
ContentTemplate="{StaticResource theTemplate}"/>
</DockPanel>

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