WPF用户控制+；MVVM

在网站上搜索了很多，阅读了很多类似的问题，但似乎没有什么能解决我对用户控制不理解的问题

我用MVVM实现了一个用户控件。基本上是一个文件夹网格，其中每个文件夹都是一个复选框和一个路径。用户可以选中复选框选择任何文件夹。 用户控件xaml是：

<UserControl x:Class="TestDP.Views.ViewCTRL" [...]>
        <DataGrid Name="GridMain" ItemsSource="{Binding Folders}">
        <DataGrid.Columns>
            <DataGridCheckBoxColumn Header="Cked" Binding="{Binding Cked,  UpdateSourceTrigger=PropertyChanged}" />
            <DataGridTextColumn Header="Path" Binding="{Binding Path}"/>
        </DataGrid.Columns>
    </DataGrid>
</UserControl>

public partial class ViewCTRL : UserControld
{
    public static DependencyProperty SelectedFoldersProperty =
        DependencyProperty.Register("SelectedFolders", typeof(ObservableCollection<Folder>), typeof(ViewCTRL),
        new FrameworkPropertyMetadata() { BindsTwoWayByDefault = true });

    public ObservableCollection<Folder> SelectedFolders
    {
        get{return (ObservableCollection<Folder>)GetValue(SelectedFoldersProperty);}
        set{SetValue(SelectedFoldersProperty, value);}}

    public ViewCTRL()
    {
        var vm = new ViewCTRLModel();
        InitializeComponent();
        GridMain.DataContext = vm;

        // bindings
        SetBinding(SelectedFoldersProperty, new Binding()
        {
            Source = GridMain.DataContext,
            Path = new PropertyPath("SelectedFoldersV"),
            UpdateSourceTrigger =   System.Windows.Data.UpdateSourceTrigger.PropertyChanged,
            Mode = BindingMode.TwoWay
        });
    }

    public class ViewCTRLModel : INotifyPropertyChanged
{
    [...]

    public void Folder_PropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        SelectedFoldersV = new ObservableCollection<Folder>(Folders.Where(x => x.Cked));
    }

    private ObservableCollection<Folder> folders;
    public ObservableCollection<Folder> Folders
    {
        get{return folders;}
        set{folders = value;OnPropertyChanged("Folders");}
    }

    private ObservableCollection<Folder> selectedFoldersV;
    public ObservableCollection<Folder> SelectedFoldersV
    {
        get{return selectedFoldersV;}
        set{selectedFoldersV = value;OnPropertyChanged("SelectedFoldersV");}
    }
    [...]
}

class ViewWPFModel : INotifyPropertyChanged
{
    public ViewWPFModel()
    {
        SelectedFoldersVMWPF = new ObservableCollection<Folder>();
        SelectedFoldersVMWPF.Add(new Folder() { Path = "uuu" });
    }

    private ObservableCollection<Folder> selectedFoldersVMWPF;
    public ObservableCollection<Folder> SelectedFoldersVMWPF
    {
        get {return selectedFoldersVMWPF;}
        set {selectedFoldersVMWPF = value; OnPropertyChanged("SelectedFoldersVMWPF");}
    }
}

后面的用户控制代码是：

<UserControl x:Class="TestDP.Views.ViewCTRL" [...]>
        <DataGrid Name="GridMain" ItemsSource="{Binding Folders}">
        <DataGrid.Columns>
            <DataGridCheckBoxColumn Header="Cked" Binding="{Binding Cked,  UpdateSourceTrigger=PropertyChanged}" />
            <DataGridTextColumn Header="Path" Binding="{Binding Path}"/>
        </DataGrid.Columns>
    </DataGrid>
</UserControl>

public partial class ViewCTRL : UserControld
{
    public static DependencyProperty SelectedFoldersProperty =
        DependencyProperty.Register("SelectedFolders", typeof(ObservableCollection<Folder>), typeof(ViewCTRL),
        new FrameworkPropertyMetadata() { BindsTwoWayByDefault = true });

    public ObservableCollection<Folder> SelectedFolders
    {
        get{return (ObservableCollection<Folder>)GetValue(SelectedFoldersProperty);}
        set{SetValue(SelectedFoldersProperty, value);}}

    public ViewCTRL()
    {
        var vm = new ViewCTRLModel();
        InitializeComponent();
        GridMain.DataContext = vm;

        // bindings
        SetBinding(SelectedFoldersProperty, new Binding()
        {
            Source = GridMain.DataContext,
            Path = new PropertyPath("SelectedFoldersV"),
            UpdateSourceTrigger =   System.Windows.Data.UpdateSourceTrigger.PropertyChanged,
            Mode = BindingMode.TwoWay
        });
    }

    public class ViewCTRLModel : INotifyPropertyChanged
{
    [...]

    public void Folder_PropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        SelectedFoldersV = new ObservableCollection<Folder>(Folders.Where(x => x.Cked));
    }

    private ObservableCollection<Folder> folders;
    public ObservableCollection<Folder> Folders
    {
        get{return folders;}
        set{folders = value;OnPropertyChanged("Folders");}
    }

    private ObservableCollection<Folder> selectedFoldersV;
    public ObservableCollection<Folder> SelectedFoldersV
    {
        get{return selectedFoldersV;}
        set{selectedFoldersV = value;OnPropertyChanged("SelectedFoldersV");}
    }
    [...]
}

class ViewWPFModel : INotifyPropertyChanged
{
    public ViewWPFModel()
    {
        SelectedFoldersVMWPF = new ObservableCollection<Folder>();
        SelectedFoldersVMWPF.Add(new Folder() { Path = "uuu" });
    }

    private ObservableCollection<Folder> selectedFoldersVMWPF;
    public ObservableCollection<Folder> SelectedFoldersVMWPF
    {
        get {return selectedFoldersVMWPF;}
        set {selectedFoldersVMWPF = value; OnPropertyChanged("SelectedFoldersVMWPF");}
    }
}

public分部类ViewCTRL:UserControld
{
公共静态从属属性SelectedFoldersProperty=
DependencyProperty.Register（“SelectedFolders”、typeof（ObservableCollection）、typeof（ViewCTRL），
新的FrameworkPropertyMetadata（）{BindsTwoWayByDefault=true}）；
公共可观察集合选定文件夹
{
get{return（ObservableCollection）GetValue（SelectedFoldersProperty）；}
set{SetValue（SelectedFoldersProperty，value）；}
公共视图Ctrl（）
{
var vm=新的ViewCTRLModel（）；
初始化组件（）；
GridMain.DataContext=vm；
//绑定
SetBinding（SelectedFoldersProperty，新绑定（）
{
Source=GridMain.DataContext，
路径=新属性路径（“SelectedFoldersV”），
UpdateSourceTrigger=System.Windows.Data.UpdateSourceTrigger.PropertyChanged，
Mode=BindingMode.TwoWay
});
}

用户控件视图模型是：

<UserControl x:Class="TestDP.Views.ViewCTRL" [...]>
        <DataGrid Name="GridMain" ItemsSource="{Binding Folders}">
        <DataGrid.Columns>
            <DataGridCheckBoxColumn Header="Cked" Binding="{Binding Cked,  UpdateSourceTrigger=PropertyChanged}" />
            <DataGridTextColumn Header="Path" Binding="{Binding Path}"/>
        </DataGrid.Columns>
    </DataGrid>
</UserControl>

public partial class ViewCTRL : UserControld
{
    public static DependencyProperty SelectedFoldersProperty =
        DependencyProperty.Register("SelectedFolders", typeof(ObservableCollection<Folder>), typeof(ViewCTRL),
        new FrameworkPropertyMetadata() { BindsTwoWayByDefault = true });

    public ObservableCollection<Folder> SelectedFolders
    {
        get{return (ObservableCollection<Folder>)GetValue(SelectedFoldersProperty);}
        set{SetValue(SelectedFoldersProperty, value);}}

    public ViewCTRL()
    {
        var vm = new ViewCTRLModel();
        InitializeComponent();
        GridMain.DataContext = vm;

        // bindings
        SetBinding(SelectedFoldersProperty, new Binding()
        {
            Source = GridMain.DataContext,
            Path = new PropertyPath("SelectedFoldersV"),
            UpdateSourceTrigger =   System.Windows.Data.UpdateSourceTrigger.PropertyChanged,
            Mode = BindingMode.TwoWay
        });
    }

    public class ViewCTRLModel : INotifyPropertyChanged
{
    [...]

    public void Folder_PropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        SelectedFoldersV = new ObservableCollection<Folder>(Folders.Where(x => x.Cked));
    }

    private ObservableCollection<Folder> folders;
    public ObservableCollection<Folder> Folders
    {
        get{return folders;}
        set{folders = value;OnPropertyChanged("Folders");}
    }

    private ObservableCollection<Folder> selectedFoldersV;
    public ObservableCollection<Folder> SelectedFoldersV
    {
        get{return selectedFoldersV;}
        set{selectedFoldersV = value;OnPropertyChanged("SelectedFoldersV");}
    }
    [...]
}

class ViewWPFModel : INotifyPropertyChanged
{
    public ViewWPFModel()
    {
        SelectedFoldersVMWPF = new ObservableCollection<Folder>();
        SelectedFoldersVMWPF.Add(new Folder() { Path = "uuu" });
    }

    private ObservableCollection<Folder> selectedFoldersVMWPF;
    public ObservableCollection<Folder> SelectedFoldersVMWPF
    {
        get {return selectedFoldersVMWPF;}
        set {selectedFoldersVMWPF = value; OnPropertyChanged("SelectedFoldersVMWPF");}
    }
}

公共类ViewCTRLModel:INotifyPropertyChanged
{
[...]
公用无效文件夹\u PropertyChanged（对象发件人，PropertyChangedEventArgs e）
{
SelectedFoldersV=新的ObservableCollection（Folders.Where（x=>x.Cked））；
}
私有可观察收集文件夹；
公共可观测集合文件夹
{
获取{返回文件夹；}
设置{folders=value；OnPropertyChanged（“folders”）；}
}
私有可观测集合selectedFoldersV；
公共可观测集合选择的文件夹SV
{
获取{return selectedFoldersV；}
设置{selectedFoldersV=value；OnPropertyChanged（“selectedFoldersV”）；}
}
[...]
}

然后，我使用一个WPF应用程序，在其中放置我的用户控件。如果我将用户控件DP SelectedFolders与ItemSource绑定，则一切正常。如果我选中用户控件的文件夹复选框，则SelectedFolder将在项目源上更新

<Window x:Class="TestDPWPF.Views.ViewWPF" [...]>
<uc:ViewCTRL Name="ViewCTRL" />
<ListBox ItemsSource="{Binding ElementName=ViewCTRL, Path=SelectedFolders}" DisplayMemberPath="Path"/>

如果我将SelectedFolders属性绑定到窗口视图模型的属性，如：

<uc:ViewCTRL Name="ViewCTRL" SelectedFolders="{Binding SelectedFoldersVMWPF,  Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />

用户控件获取由window viewmodel传递的初始值，但随后绑定似乎中断，选择任何文件夹都不会更新SelectedFoldersVMWPF绑定。

视窗的视图模型是：

<UserControl x:Class="TestDP.Views.ViewCTRL" [...]>
        <DataGrid Name="GridMain" ItemsSource="{Binding Folders}">
        <DataGrid.Columns>
            <DataGridCheckBoxColumn Header="Cked" Binding="{Binding Cked,  UpdateSourceTrigger=PropertyChanged}" />
            <DataGridTextColumn Header="Path" Binding="{Binding Path}"/>
        </DataGrid.Columns>
    </DataGrid>
</UserControl>

public partial class ViewCTRL : UserControld
{
    public static DependencyProperty SelectedFoldersProperty =
        DependencyProperty.Register("SelectedFolders", typeof(ObservableCollection<Folder>), typeof(ViewCTRL),
        new FrameworkPropertyMetadata() { BindsTwoWayByDefault = true });

    public ObservableCollection<Folder> SelectedFolders
    {
        get{return (ObservableCollection<Folder>)GetValue(SelectedFoldersProperty);}
        set{SetValue(SelectedFoldersProperty, value);}}

    public ViewCTRL()
    {
        var vm = new ViewCTRLModel();
        InitializeComponent();
        GridMain.DataContext = vm;

        // bindings
        SetBinding(SelectedFoldersProperty, new Binding()
        {
            Source = GridMain.DataContext,
            Path = new PropertyPath("SelectedFoldersV"),
            UpdateSourceTrigger =   System.Windows.Data.UpdateSourceTrigger.PropertyChanged,
            Mode = BindingMode.TwoWay
        });
    }

    public class ViewCTRLModel : INotifyPropertyChanged
{
    [...]

    public void Folder_PropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        SelectedFoldersV = new ObservableCollection<Folder>(Folders.Where(x => x.Cked));
    }

    private ObservableCollection<Folder> folders;
    public ObservableCollection<Folder> Folders
    {
        get{return folders;}
        set{folders = value;OnPropertyChanged("Folders");}
    }

    private ObservableCollection<Folder> selectedFoldersV;
    public ObservableCollection<Folder> SelectedFoldersV
    {
        get{return selectedFoldersV;}
        set{selectedFoldersV = value;OnPropertyChanged("SelectedFoldersV");}
    }
    [...]
}

class ViewWPFModel : INotifyPropertyChanged
{
    public ViewWPFModel()
    {
        SelectedFoldersVMWPF = new ObservableCollection<Folder>();
        SelectedFoldersVMWPF.Add(new Folder() { Path = "uuu" });
    }

    private ObservableCollection<Folder> selectedFoldersVMWPF;
    public ObservableCollection<Folder> SelectedFoldersVMWPF
    {
        get {return selectedFoldersVMWPF;}
        set {selectedFoldersVMWPF = value; OnPropertyChanged("SelectedFoldersVMWPF");}
    }
}

class ViewWPFModel:INotifyPropertyChanged
{
公共视图wpfmodel（）
{
SelectedFoldersVMWPF=新的ObservableCollection（）；
选择edfoldersvmwpf.Add（新文件夹（）{Path=“uuu”}）；
}
私有可观测集合选择FoldersVMWPF；
公共可观测集合选择的文件夹SVMWPF
{
获取{return selectedFoldersVMWPF；}
设置{selectedFoldersVMWPF=value；OnPropertyChanged（“selectedFoldersVMWPF”）；}
}
}

---

我在输出窗口中没有关于绑定的任何消息，因此所有绑定路径都应该是正常的。我认为窗口视图模型和控件的DP之间的绑定被用户控件和用户控件视图模型之间的绑定破坏。但是我不知道为什么以及如何解决问题。我试图更改用户的DataContex控件，但结果总是一样的。任何人都可以将我引向正确的方向？

在第一个示例中，您已将ViewCTRL的SelectedFolders DependencyProperty绑定到ViewCTRLModel的SelectedFoldersV。然后，列表框的ItemsSource将绑定到SelectedFolders DependencyProperty

在第二个示例中，您已将ViewCTRL的SelectedFolders DependencyProperty绑定到ViewWPFModel的SelectedFoldersVMWPF属性（在ViewCTRL构造函数中的InitializeComponent（）调用期间）。但紧接着，SetBindings调用将绑定更改为ViewCTRLModel的SelectedFoldersV

我以前没有这样做过，但我认为如果您将ViewModel中的SelectedFoldersV更改为DependencyProperty，并对ViewCTRL构造函数进行以下更改，则应该可以这样做：

    SetBinding(vm.SelectedFoldersVProperty, new Binding()
    {
        Source = this,
        Path = new PropertyPath("SelectedFolders"),
        UpdateSourceTrigger = System.Windows.Data.UpdateSourceTrigger.PropertyChanged,
        Mode = BindingMode.TwoWay
    });

---

请注意，可能有更好的方法来实现您正在尝试的操作（例如使用MVVM Light的Messenger在ViewModels之间传达这些更改）。我个人不想将一堆绑定链接在一起，因为我认为这会让人更加困惑。

欢迎使用Stack Overflow。作为将来的参考，您在这个问题中显示了太多的代码。在这个网站上，您应该向我们展示这些代码。这样做将帮助您和我们，并确保您能够快速获得答案-请注意，由于代码超载，您仍然没有收到一个答案。@puckk sheridan是对的…您的代码似乎混乱了…在您的usercontrol数据网格项中，当您的DP名称为Selected Folders时，源绑定到文件夹。为什么您需要在usercontrol构造函数中调用setbinding？稍微清理了代码…希望我现在更好：）。@nit Datagrid Itemsource绑定到用户控件viewmodel的文件夹。设置集合更改SelectedFoldersV时。在构造函数上设置绑定DP（SelectedFoldersProperty）选择用户控件viewmodel的适当性。用户控件VM上的dependency属性是一个非常好的尝试。实现了它，但不起作用。所有绑定似乎都可以，但VM上的DP不会通知后面代码上的DP。我不明白为什么。应该可以，但不行。因此，对于sug，我将使用MVVM Light.Thx手势。