CODEWITHSUNDEEP
c#xamluwp
GrooverFromHolland
GrooverFromHolland

Reputation: 1029

UWP Listview binding error

In my UWP app mainpage xaml I try to bind an ObservableCollection<BluetoothLEDevice> BleDeviceList to a listview.
If I run my app I get the following error:

System.InvalidCastException: Unable to cast object of type 'Windows.Devices.Bluetooth.BluetoothLEDevice' to type 'UWPsimpleBLE_exampleWithSomeControls.MainPage'. at UWPsimpleBLE_exampleWithSomeControls.MainPage.MainPage_obj2_Bindings.SetDataRoot(Object newDataRoot) at UWPsimpleBLE_exampleWithSomeControls.MainPage.MainPage_obj2_Bindings.ProcessBindings(Object item, Int32 itemIndex, Int32 phase, Int32& nextPhase)

 <Page.Resources>
    <DataTemplate x:Key="ListDataTemplate" x:DataType="local:MainPage">
        <StackPanel Orientation="Horizontal" HorizontalAlignment="Left">
            <TextBlock Text="{x:Bind Path=BleDevice.Name }" HorizontalAlignment="Center" Width="150" />
            <StackPanel Margin="20,20,0,0">
                <!--<TextBlock Text="{x:Bind BleDevice.BluetoothAddress.ToString()}" HorizontalAlignment="Left" FontSize="16" />-->
                <!--<TextBlock Text="{x:Bind BleDevice.ConnectionStatus}" HorizontalAlignment="Left" FontSize="10" />-->
            </StackPanel>
        </StackPanel>
    </DataTemplate>
</Page.Resources>



 <ListView HorizontalAlignment="Stretch" Height="100" Margin="0,0,0,0"
                  VerticalAlignment="Top" Background="#FFDED7D7" 
                  BorderBrush="#FFF88686" Foreground="Black" 
                  ItemsSource="{x:Bind BleDeviceList}"
                  ItemTemplate="{StaticResource ListDataTemplate }">
        </ListView>

If i comment out the line TextBlock Text.. The error is gone,so I must be doing something wrong with my binding

Upvotes: 0

Views: 288

Answers (1)

gregkalapos
gregkalapos

Reputation: 3619

As discussed in the comments the solution was to change the x:DataType from MainPage to BluetoothLEDevice class. Additionally the BluetoothLEDevice class also had to be imported. In case of x:Bind you have to define the type of the class that you bind to and in this case the correct class was BluetoothLEDevice.

So this should be the code which does the job:

<DataTemplate x:Key="ListDataTemplate" x:DataType="local:BluetoothLEDevice">

And this line makes the BluetoothLEDevice class visible within the XAML page:

xmlns:local="using:Windows.Devices.Bluetooth"

This page describes x:Binds with DataTemplates (especially the "DataTemplate and x:DataType" part).

Upvotes: 1

Related Questions