How do I assign a variable to a Textblock within a DataTemplate in a ListViewHeader?

Question

I have a DataTemplate inside a ListViewHeader with a Textblock inside it. I want this Textblock to have a string variable that I give it in code in the cs file. However, because it's in a DataTemplate, the Textblock is not recognized in the cs file. So, how do I assign the textblock's text property a variable's value?

Answer 1

Hello,​

Welcome to our Microsoft Q&A platform!

You can assign the variable to ListView.Header:

xaml

<ListView.HeaderTemplate>

<DataTemplate>

<TextBlock Text="{Binding}" Foreground="Red"/>

</DataTemplate>

</ListView.HeaderTemplate>

xaml.cs

TestListView.Header = "Test";

---

If you need to set the header using bindings, in order to change the UI when you change the variable, you need to implement the INotifyPropertyChanged interface:

public sealed partial class MainPage : Page, INotifyPropertyChanged
{
    private string _testHeader;
    public string TestHeader
    {
        get => _testHeader;
        set
        {
            _testHeader = value;
            OnPropertyChanged();
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;
    public void OnPropertyChanged([CallerMemberName]string propertyName = "")
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }

    // ....
}

Usage

<ListView x:Name="TestListView" Header="{x:Bind TestHeader,Mode=OneWay}" ... >
...
</ListView>

Thanks.