我想通过 XAML 代码中的属性在其中插入另一个 UserControl 的项目和 contentControl 的用户控件如何？

Question

This is a graphic idea of what I want to achieve I will call it SuperControl:

---------------------------------------------  
|                                           |  
|   ----------   ------------------------   |  
|   | Button |   |  TextBox             |   |  
|   ----------   ------------------------   |  
|                                           |  
|    ------------------------------------   |  
|    |                                  |   |  
|    |    Another UserControl that      |   |  
|    |    can be different depending    |   |  
|    |    on the problem to be solved   |   |  
|    |                                  |   |
|    ------------------------------------   |
|                                           |
---------------------------------------------

The UserControl inserted will remain constant for the rest of the execution. This is my aproach

<UserControl x:Class="App.GUI.Items.SuperControl">
     <Grid>
         <!-- Some row and column definitions -->
         <Button Content="Button" Click="Btn_Click" Grid.Column="0" Grid.Row="0"/>
         <TextBox Text="textBox" Grid.Column="1" Grid.Row="0"/>
         <ContentControl x:Name="innerForm" Grid.Row="0" Grid.ColumnSpan="2"/>
     </Grid>
</UserControl>

And I created a DependencyProperty

   public partial class SuperControl : UserControl
    {
        public SuperControl()
        {
            InitializeComponent();
            //I know that I have declare a new Userform(), but I do not know how
            innerForm = this.InnerForm; 
        }

        public static readonly DependencyProperty InnerFormProperty =
            DependencyProperty.Register("InnerForm", typeof(UserControl), typeof(SuperControl));

        public UserControl InnerForm
        {
            get { return (UserControl)GetValue(InnerFormProperty); }
            set { SetValue(InnerFormProperty, value); }
        }
    }

Because my idea is to be able to define the SuperControl this way:

<Items:SuperControl InnerForm="OneOfTheSeveralUserControlsIMightWantToInsert.xaml"/>

But I do not know what to write in the InnerForm property to pass a UserControl class and make this code work.

Do you have any idea? Is this even posible?

Answer 1

You're nearly there - I copied your code, tweaked it a bit and got the result you wanted (if a slightly different path there).

In the SuperControl , switch your ContentControl for a ContentPresenter like so:

    <ContentPresenter Margin="58,118,318,52" Content="{Binding InjectedContent, ElementName=superControl}">
    </ContentPresenter>

The SuperControl declaration (top level of XAML) will also need a name property, in my example I called it "superControl".

Wherever you're using the SuperControl, you can set a user control using the InnerForm property (already set up with dependency binding etc):

    <local:SuperControl>
        <local:SuperControl.InjectedContent>
            <Rectangle Fill="Red" />
        </local:SuperControl.InjectedContent>
    </local:SuperControl>

In my example I've used a Rectangle but you will need to use something that inherits from UserControl (since I was binding to type object rather than a UserControl).

I made the assumption that you weren't 100% committed to providing a string path to a XAML file to inject, and that you just needed to specify a user control. This answer has the benefit of being able to set properties on the user control in XAML too, if required.

Hope this helps :)