c# - Wpf + Caliburn 微 : Binding Textbox to a custom object

Question

我使用 Wpf 4.5 和 Caliburn Micro 2.0.2。

我想将文本框绑定(bind)到 View 模型的属性。该属性(称为 ResultData)是 TextXmlData 类中的一个对象。该类是从 xsd 自动生成的类。我使用 Microsoft Xsd.exe 来制作它。

这是 View 模型

public class ShellViewModel : PropertyChangedBase, IHaveDisplayName
{
    public string DisplayName { get; set; }
    private TestXmlData _resultData;
    public TestXmlData ResultData
    {
        get { return _resultData; }
        set
        {
            _resultData = value;
            NotifyOfPropertyChange(() => _resultData);
        }
    }

    public ShellViewModel()
    {
        DisplayName = "Shell Window";
    }

    public void CreateObject()
    {
        String xmlData = "<TestXmlData><Id>88</Id><Name>What a name</Name></TestXmlData>";
        if (ResultData == null) { ResultData = new TestXmlData(); }
        XmlSerializer oXmlSerializer = new XmlSerializer(ResultData.GetType());
        ResultData = (TestXmlData)oXmlSerializer.Deserialize(new StringReader(xmlData)); 
        // at this point the debugger shows that the ResultData is correctly filled, 
        // the Name is definitely not empty
    }
}

这是 View

<UserControl x:Class="CMWpfXmlSerializer2Ways.Views.ShellView"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         d:DesignHeight="300"
         d:DesignWidth="300"
         mc:Ignorable="d">
<Grid Width="300" Height="300">
    <StackPanel Width="200"
                Height="100"
                HorizontalAlignment="Center"
                VerticalAlignment="Center">
        <Button x:Name="CreateObject"
                Width="190"
                Content="Create Object from XML" />
        <TextBox Width="190"
                 DataContext="{Binding ResultData}"
                 Text="{Binding Name}" />
    </StackPanel>

</Grid>
</UserControl>

并且 TextBox 始终显示为空!

我也尝试过使用 Text="{Binding ResultData.Name}"，但 TextBox 仍然显示为空。

任何人都可以帮助并告诉我上面的代码有什么问题吗？请随时修改代码。提前致谢。

Answer 1

ResultData 是 ViewModel 的一个属性。因此，您需要在较高级别将 ViewModel 设置为 DataContext，然后您可以在较低级别将其属性用作绑定(bind)源。

为了运行您的示例，我做了一些更改并像下面这样运行:

<TextBox x:Name="tbName" DataContext="{Binding ResultData}" Text="{Binding Name}" />

///

public partial class MainWindow : Window
{
    public MainWindow()
    {  
        InitializeComponent();
        ShellViewModel vm = new ShellViewModel();
        vm.CreateObject();

        this.DataContext = vm;
    } 
    ...

///

public class ShellViewModel : INotifyPropertyChanged
    {
        public string DisplayName { get; set; }
        private TestXmlData _resultData;
        public TestXmlData ResultData
        {
            get { return _resultData; }
            set
            {
                _resultData = value;
                OnPropertyChanged("ResultData");
            }
        }

        public void OnPropertyChanged(string name)
        {
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs(name));
        }

        public ShellViewModel()
        {
            DisplayName = "Shell Window";
        }

        public void CreateObject()
        {
            String xmlData = "<TestXmlData><Id>88</Id><Name>What a name</Name></TestXmlData>";
            if (ResultData == null) { ResultData = new TestXmlData(); }
            XmlSerializer oXmlSerializer = new XmlSerializer(ResultData.GetType());
            ResultData = (TestXmlData)oXmlSerializer.Deserialize(new StringReader(xmlData));
            // at this point the debugger shows that the ResultData is correctly filled, 
            // the Name is definitely not empty
        }

        public event PropertyChangedEventHandler PropertyChanged;
    }