Question

我有一个UserControl LetterInRowUserControl与LongListSelector和ItemTemplate在xaml部分

<UserControl>
...
    <UserControl.Resources>
            <DataTemplate x:Key="itemTemplate">            
                <local:LetterControl x:Name="letterControl" VerticalAlignment="Top" Width="50" Letter="{Binding}"/>
            </DataTemplate>
    </UserControl.Resources>

    <Grid x:Name="LayoutRoot">
        <phone:LongListSelector x:Name="lls" LayoutMode="List" ItemTemplate="{StaticResource itemTemplate}" />
    </Grid>
</UserControl>

cs part：

public partial class LetterInRowUserControl : UserControl
{
    public LetterInRowUserControl()
    {
        InitializeComponent();
        LetterControl.TextChanged += (o, ev) =>
        {
            var conv = new StringToListConverter();
            ContainsLetters = (string)conv.ConvertBack(lls.ItemsSource, typeof(string), null, CultureInfo.CurrentCulture);

        };
    }

    public static readonly DependencyProperty ContainsLettersProperty =
        DependencyProperty.Register("ContainsLetters", typeof (string), typeof (LetterInRowUserControl), new PropertyMetadata(default(string),
            (o, args) =>
            {
                var control = (LetterInRowUserControl) o;
                var conv = new StringToListConverter();
                control.lls.ItemsSource = (ObservableCollection<string>)conv.Convert(args.NewValue, typeof(string), null, CultureInfo.CurrentCulture);
            }));


    public string ContainsLetters
    {
        get
        {
            return (string) GetValue(ContainsLettersProperty);
        }
        set
        {
            SetValue(ContainsLettersProperty, value);
        }
    }


}

然后我有第二个Usercontrol - LetterControl，它在LetterInRowUserControl的itemtemplate里面

xaml part：

<UserControl>
...

<Grid x:Name="LayoutRoot">
    <Grid>
        <Button x:Name="hidden" Height="0" Width="0"/>                      
        <TextBox x:Name="textBox" 
                 TextWrapping="Wrap" VerticalAlignment="Top" Height="84" Margin="-12" FontFamily="Segoe WP Semibold" FontSize="33.333" TextAlignment="Center" GotFocus="textBox_GotFocus" LostFocus="textBox_LostFocus" MaxLength="1" TextChanged="textBox_TextChanged"/>
    </Grid>

</Grid>
</UserControl>

和cs part：

public partial class LetterControl : UserControl
{
    public static event TextChangedEventHandler TextChanged;

    public static readonly DependencyProperty LetterProperty =
        DependencyProperty.Register("Letter", typeof(string), typeof(LetterControl), new PropertyMetadata(default(string),
            (o, args) =>
            {
                var control = (LetterControl)o;
                control.textBox.Text = (string)args.NewValue;
            }));

    public string Letter
    {
        get { return (string)GetValue(LetterProperty); }
        set
        {
            SetValue(LetterProperty, value);               
        }
    }
    public LetterControl()
    {
        InitializeComponent();
    }

    private void textBox_GotFocus(object sender, RoutedEventArgs e)
    {
        textBox.SelectAll();
    }

    private void textBox_LostFocus(object sender, RoutedEventArgs e)
    {
        textBox.Text = textBox.Text.ToUpper();
    }

    private void textBox_TextChanged(object sender, TextChangedEventArgs e)
    {
       SetValue(LetterProperty,textBox.Text);

        if(textBox.Text.Length>=1)
        hidden.Focus();

        if (TextChanged != null) TextChanged.Invoke(sender, e);

    }


}

基本上有两个UserControl：LetterInRowUserControl和LetterControl。

LetterInRowUserControl在其ItemTemplate中包含带有LetterControl的LongListSelector。

问题在于，如果我从LetterControl内部更改Property Letter，它不会影响LetterInRowUserControl中LongListSelector中的ItemSource。相反（如果我直接更改ItemSource）它没有问题。

how it looks

/打算用于一个Windows Phone 8应用程序

...类似于一个字母的文本框的列表框 - 问题是如果我编辑一个字母列表框的ItemSource没有改变。编辑：经过努力尝试，我成功了。我的代码正在运行。主要问题是我使用的是ObservableCollection<string>而不是ObservableCollection<CustomObjectWithINotifyPropChangedImplementation>.所以该值并未自动更改（ObservableCollection未实现其功能）。

绑定到DependencyProperty不会按预期更新LongListSelector项

0 个答案: