Question

I have a C# class like this :

public partial class MyClass: UserControl
{
    public String SomeText{get;set;}
    ...

    public MyClass(String Text)
    {
        this.InitializeComponent();
        SomeText = Text;
    }

}

And I would like to get the attribute SomeText in my XAML file. How to do something like this ?

<TextBlock Text="{THIS IS HERE I WANT TO HAVE SomeText}"></TextBlock>

I am new to C# so I don’t know how to do. There must be a simple way?

Answer 1

Give the UserControl element a Name and then bind to it as in the example below. If your text isn’t going to change you should define it before your call to InitialiseComponent.

<UserControl x:Class="WpfApplication1.UserControl1"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" 
             d:DesignHeight="300" d:DesignWidth="300"
             x:Name="root">
    <Grid>
        <TextBlock Text="{Binding SomeText,ElementName=root}"/>
    </Grid>
</UserControl>

If your SomeText is likely to change then you need to declare it as a DependencyProperty instead of a plain old string property. This would look something like below:

    public string SomeText
    {
        get { return (string)GetValue(SomeTextProperty); }
        set { SetValue(SomeTextProperty, value); }
    }

    // Using a DependencyProperty as the backing store for SomeText.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty SomeTextProperty =
        DependencyProperty.Register("SomeText", typeof(string), typeof(UserControl1), new UIPropertyMetadata(""));

You should then change your binding to look like the below, which will cause the UI to update when you change the value of SomeString.

<TextBlock Text="{Binding SomeText,ElementName=root,UpdateSourceTrigger=PropertyChanged}"/>