Warum ist myTextBox null ?
<Grid>
<CheckBox x:Name="myCheckBox" IsChecked="True" Checked="myCheckBox_Checked"></CheckBox>
<TextBlock x:Name="myTextBox" Text=""></TextBlock>
</Grid>
public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
}
private void myCheckBox_Checked(object sender, RoutedEventArgs e)
{
myTextBox.Text = "Checked";
}
}