xaml文件的WPF绑定根元素不起作用：

我试图将dataContext绑定到网格（下面是xaml）

将datacontext更改为没有标题的NewFormViewModel。所有剩余的绑定都失败

如果我将开头更改为：

<Canvas x:Class="NewForm"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
      mc:Ignorable="d" Height="398" Width="377"

     >
    <Grid DataContext="{Binding Path=NewFormViewModel}" >

---

如果控件层次结构（如窗口或用户控件）中存在（在其DataContext中）拥有您正在查询的属性（NewFormViewModel）的对象，则根元素中的绑定应该起作用

这正是我首先想到的。但是，在上述所有4个示例中，控件层次结构始终相同，即加载xaml文件的帧始终保持不变，帧的dataContext始终相同。但是由于某种原因，xaml中的根元素不绑定，而子元素绑定。我只是好奇为什么会这样。。不过，感谢您的输入。由于绑定在子对象上工作，并且dataContext由子对象继承，因此我认为可以安全地假设父对象也将具有相同的dataContext。特别是因为我使用的是在主窗口上设置的DataContext，所以我们可以看到关于如何填充和不工作的完整示例。我添加了代码。让我的问题变得难以置信的大（不发布它的主要原因）。我希望有帮助。非常感谢你抽出时间来帮助我：）对不起。。。也许我遗漏了一些东西，但看不到您放置提供所有您声明的属性的对象的位置。在“content.DataContext=frame.DataContext；”行中“frame.DataContext”如何获取其数据？

<Grid  ....> 
  <Canvas DataContext="{Binding Path=NewFormViewModel}">
      ....
  </Canvas>
</Grid>

<Canvas....    DataContext="{Binding Path=NewFormViewModel}"  > ...</Canvas>

   <Canvas....> 
      <Grid DataContext="{Binding Path=NewFormViewModel}">
          ....
      </Grid>
    </Canvas>

         Window   <- Data binding to object o
           |
           *
          Frame     <-Data binding to obect o inherited
           |
           *
         Canvas/Grid <- Data binding to o.NewFormViewModel failed
           |
           *
         Canvas/Grid <- Data binding to o.NewFormViewModel Succeeds

<Canvas x:Class="WPFEditors.NewForm"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
      mc:Ignorable="d" Height="398" Width="377"
      DataContext="{Binding Path=NewFormViewModel}"
     >
    <Grid  >
    <Label DataContext="Form Type" Height="31" HorizontalAlignment="Left" Margin="12,22,0,0" VerticalAlignment="Top" Width="92" />
    <ComboBox Margin="148,22,6,347" ItemsSource="{Binding Path=FormTypes}" />
    <Label Content="Description" Height="31" HorizontalAlignment="Left" Margin="12,58,0,0"  VerticalAlignment="Top" Width="92" />
    <Label Content="{Binding Path=Heading}" ToolTip="This is pulled from the Enum defined for FormTypes" Margin="148,59,6,309" />   
    <Label Content="Version" Height="31" HorizontalAlignment="Left" Margin="12,95,0,0"  VerticalAlignment="Top" Width="92" />
    <TextBox Text="Bind this later" Margin="148,97,6,270" Height="31" />
    <Label Content="Approval Level" Height="31" HorizontalAlignment="Left" Margin="12,132,0,0" VerticalAlignment="Top" Width="92" />
    <TextBox Height="31" Margin="148,134,6,233" Text="Bind this later" />
    <Label Content="Number of Approvals" Height="31" HorizontalAlignment="Left" Margin="12,171,0,0" VerticalAlignment="Top" Width="130" />
    <TextBox Height="31" Margin="148,173,6,194" Text="Bind this later" />
    <Label Content="Heading" Height="31" HorizontalAlignment="Left" Margin="12,210,0,0" VerticalAlignment="Top" Width="130" />
    <TextBox Height="31" Margin="148,212,6,155" Text="Bind this later" />
    <Label Content="Static Data Id" Height="31" HorizontalAlignment="Left" Margin="12,247,0,0" VerticalAlignment="Top" Width="130" />
    <TextBox Height="31" Margin="148,249,6,118" Text="Bind this later" />
    <Label Content="{Binding  Path=Errors}" Background="{Binding Path=Color}" Margin="12,325,6,6" BorderThickness="1" BorderBrush="#FF000019" />
    <Button Content="Create" Margin="83,294,202,78" />
    <Button Content="Create" Margin="181,294,104,78" />
    <Button Content="Create" Margin="279,294,6,78" />
    </Grid>
</Canvas>

<Label Content="{Binding Path=Heading}" 

 DataContext="{Binding Path=NewFormViewModel}"

<Canvas x:Class="NewForm"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
      mc:Ignorable="d" Height="398" Width="377"

     >
    <Grid DataContext="{Binding Path=NewFormViewModel}" >

<Window x:Class="WPFEditors.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="{Binding Path=Heading}" Height="743" Width="1177">

    <StackPanel  >
        <Menu IsMainMenu="True" >
            <MenuItem Header="New">
                <MenuItem Header="New Form" Command="{Binding Path=MenuCommand}" />
            </MenuItem>    
            <MenuItem Header="Edit Form"  ItemsSource="{Binding Path=FormsAvailable}" />
            <MenuItem Header="Edit Rules" />            
        </Menu>

        <Frame  NavigationUIVisibility="Hidden" Source="{Binding Path=CurrentPage}"
                LoadCompleted="Frame_LoadCompleted"
                DataContextChanged="Frame_DataContextChanged"
                Name="frame">
        </Frame>
    </StackPanel>

</Window>

private void Frame_LoadCompleted(object sender, NavigationEventArgs e)
{
    UpdateFrameDataContext(); 
}

private void Frame_DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
{
    UpdateFrameDataContext(); 
}

private void UpdateFrameDataContext()
{
    var content = frame.Content as FrameworkElement; 
    if (content == null) 
        return; 
    content.DataContext = frame.DataContext;  
}