CODEWITHSUNDEEP
c#wpfxaml
Darren Ng
Darren Ng

Reputation: 373

Access Elements in DataTemplate

I have the following item template (I tried to strip all the non relevant stuff):

<s:SurfaceWindow.Resources>
    <ResourceDictionary>
        <Style TargetType="{x:Type s:SurfaceListBox}">
            <Setter Property="ItemTemplate">
                <DataTemplate DataType="{x:Type local:myClass}"> //my own class
                    <s:SurfaceButton>
                        <TextBlock Text="{Binding name}">        //name is a string in my own class
//and close all the tags

The idea is that my listbox will contain buttons which are displaying some words on it.

Further down, I have a SurfaceListBox using the above resource. I add in an item by:

myListBox.Items.Add(new myClass("My Name"));

And it would add a button to the listbox nicely, with the button displaying "My Name".

Now I need to change "My Name" to another string.

How do I access that TextBlock?

I have tried googling but the solutions to access items in DataTemplate they all require VisualTreeHelper.GetChildrenCount via FindVisualChild, which returns 0 for me so it doesn't work.

Upvotes: 0

Views: 139

Answers (1)

Haris Hasan
Haris Hasan

Reputation: 30097

The simple and right way to achieve this is using DataBinding.

Update the TextBlock XAML so that TextBlock can update itself whenever backend name property changes

<TextBlock Text="{Binding name, UpdateSourceTrigger=PropertyChanged}">

In you myClass implement INotifyPropertyChanged. Then whenever you wish to change the text call PropertyChanged event. 

public name
{
    get
    {
        return _name;
    }
    set
    {
        _name = value;
        PropertyChanged("name");
    }
}

Upvotes: 2

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