Question

我在Silverlight风格中遇到绑定问题。

这是我的viewmodel：

public class MyObject
{
    public Uri TheUrl { get; set; }
    public string MyText { get; set; }
}

public class ViewModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    public MyObject Object1 { get { return new MyObject { TheUrl = new Uri("test.png", UriKind.Relative), MyText = "Test1" }; } }
    public MyObject Object2 { get { return new MyObject { TheUrl = new Uri("test.png", UriKind.Relative), MyText = "Test2" }; } }
}

这是我的xaml：

    <UserControl.Resources>
    <Style x:Key="TestStyle" TargetType="Button">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="Button">
                    <StackPanel>
                        <TextBlock Text="{Binding MyObject.MyText}" />
                        <Image Source="{Binding MyObject.TheUrl}" />
                    </StackPanel>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</UserControl.Resources>

<UserControl.DataContext>
    <vm:ViewModel />
</UserControl.DataContext>

<StackPanel x:Name="LayoutRoot" Background="White">
    <Button Style="{StaticResource TestStyle}" Width="100" Height="100" Tag="{Binding Object1}" />
    <Button Style="{StaticResource TestStyle}" Width="100" Height="100" Tag="{Binding Object2}" />
</StackPanel>

我用我的风格测试很多东西，但不能使绑定工作。

有人有想法吗？

提前感谢您的帮助最好的问候。

编辑：

对viewmodel的更改：

public class MyObject : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    private void NotifyPropertyChanged(String propertyName)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (null != handler)
        {
            handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    private Uri _TheUrl;
    public Uri TheUrl
    {
        get { return _TheUrl; }
        set
        {
            _TheUrl = value;
            NotifyPropertyChanged("TheUrl");
        }
    }

    private string _MyText;
    public string MyText
    {
        get { return _MyText; }
        set
        {
            _MyText = value;
            NotifyPropertyChanged("MyText");
        }
    }
}

public class ViewModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    private void NotifyPropertyChanged(String propertyName)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (null != handler)
        {
            handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    private MyObject _Object1;
    public MyObject Object1
    {
        get { return _Object1; }
        set
        {
            _Object1 = value;
            NotifyPropertyChanged("Object1");
        }
    }

    private MyObject _Object2;
    public MyObject Object2
    {
        get { return _Object2; }
        set
        {
            _Object2 = value;
            NotifyPropertyChanged("Object2");
        }
    }

    public ViewModel()
    {
        Object1 = new MyObject {TheUrl = new Uri("test.png", UriKind.Relative), MyText = "Test1"};
        Object2 = new MyObject { TheUrl = new Uri("test.png", UriKind.Relative), MyText = "Test2" };
    }
}

Answer 1

似乎在Button上使用DataContext而不是Tag正在运行

Answer 2

您的课程未正确实施INotifyPropertyChanged界面。

添加此方法：

private void NotifyPropertyChanged(String propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (null != handler)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }

向您的媒体资源制定者添加对NotifyPropertyChanged

的调用

private Uri _TheUrl;

public Uri TheUrl { 
    get { return _TheUrl;} 
    set { 
        _TheUrl = value; 
        NotifyPropertyChanged("TheUrl");
    } 
}

您应该与Object1和Object2相同（基本上与您想要绑定的所有对象）

Silverlight风格和绑定

2 个答案: