[英]WPF Binding Confusion: Composite DependencyObject
我有一个如下的DependencyObject类组成:
public class A : DependencyObject {
public AB AB { get { ... } set { ... } }
public AB AC { get { ... } set { ... } }
}
public class AB : DependencyObject {
public string Property1 { get { ... } set { ... } }
public string Property2 { get { ... } set { ... } }
public string Property3 { get { ... } set { ... } }
}
public class AC : DependencyObject {
public string Property1 { get { ... } set { ... } }
public string Property2 { get { ... } set { ... } }
}
在A,AB和AC上,所有属性通常执行通常引用静态属性的典型GetValue和SetValue操作。
现在,类A,AB和AC具有相应的UserControls AGroupBox,ABGrid,ACGrid。 AGroupBox具有根A类的根属性,ABGrid具有根AB类的根属性,而ACGrid具有根AC类的根属性。
ABGrid和ACGrid都具有有效的绑定(例如,ABGrid包含一个TextBox控件,其Text属性双向绑定到AB的Property1。)我已经通过创建一个简单的Window并将ABGrid成为Window的唯一Content子对象以及设置背后的代码来验证了这一点。 ABGrid.AB =新的AB(); ACGrid.AC = new AC();的情况相同。
问题是当我尝试对AGroupBox进行类似处理时。 我尝试将AGroupBox添加为XAML中Window内容的单个子项,并将AGroupBox.A属性设置为new A(){AB = new AB(),AC = new AC()}; 并且控件的绑定失败。 AB和AC具有其PropertyN属性的默认值。
关于我所缺少的任何见解? 我应该走其他路线吗?
编辑:附加注释-如果我将字符串属性添加到A,(String1)并将其绑定到GroupBox的Text部分,则对该属性的绑定有效,但对A的AC和AB属性无效。
EDIT-2:根据David Hay的请求(所有代码都在命名空间wpfStackOverflow中):
A.cs
public class A : DependencyObject {
static public DependencyProperty BProperty { get; private set; }
static public DependencyProperty CProperty { get; private set; }
static public DependencyProperty PropertyProperty { get; private set; }
static A() {
BProperty = DependencyProperty.Register("B", typeof(B), typeof(A));
CProperty = DependencyProperty.Register("C", typeof(C), typeof(A));
PropertyProperty = DependencyProperty.Register("Property", typeof(string), typeof(A));
}
public B B {
get { return (B)GetValue(BProperty); }
set { SetValue(BProperty, value); }
}
public C C {
get { return (C)GetValue(CProperty); }
set { SetValue(CProperty, value); }
}
public string Property {
get { return (string)GetValue(PropertyProperty); }
set { SetValue(PropertyProperty, value); }
}
public A() {
Property = "A's Default Value";
B = new B();
C = new C();
}
}
B.cs
public class B : DependencyObject {
static public DependencyProperty PropertyProperty { get; private set; }
static B() {
PropertyProperty = DependencyProperty.Register("Property", typeof(string), typeof(B));
}
public string Property {
get { return (string)GetValue(PropertyProperty); }
set { SetValue(PropertyProperty, value); }
}
public B() {
Property = "B's Default Value";
}
}
抄送
public class C : DependencyObject {
static public DependencyProperty PropertyProperty { get; private set; }
static C() {
PropertyProperty = DependencyProperty.Register("Property", typeof(string), typeof(C));
}
public string Property {
get { return (string)GetValue(PropertyProperty); }
set { SetValue(PropertyProperty, value); }
}
public C() {
Property = "C's Default Value";
}
}
AGroupBox.xaml
<UserControl
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:wpfStackOverflow"
x:Class="wpfStackOverflow.AGroupBox"
DataContext="{Binding RelativeSource={RelativeSource Self}, Path=A}"
Width="300"
Height="72"
>
<GroupBox Header="{Binding Property}">
<StackPanel >
<local:BGrid B="{Binding B}"/>
<local:CGrid C="{Binding C}"/>
</StackPanel>
</GroupBox>
</UserControl>
AGroupBox.xaml.cs
public partial class AGroupBox : UserControl {
static public DependencyProperty AProperty { get; private set; }
static AGroupBox() {
AProperty = DependencyProperty.Register("A", typeof(A), typeof(AGroupBox));
}
public A A {
get { return (A)GetValue(AProperty); }
set { SetValue(AProperty, value); }
}
public AGroupBox() {
InitializeComponent();
}
}
BGrid.xaml
<UserControl
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
x:Class="wpfStackOverflow.BGrid"
DataContext="{Binding RelativeSource={RelativeSource Self}, Path=B}"
>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition />
</Grid.ColumnDefinitions>
<Label Grid.Column="0" Content="Property"/>
<TextBox Grid.Column="1" Text="{Binding Property}"/>
</Grid>
</UserControl>
BGrid.xaml.cs
public partial class BGrid : UserControl {
static public DependencyProperty BProperty { get; private set; }
static BGrid() {
BProperty = DependencyProperty.Register("B", typeof(B), typeof(BGrid));
}
public B B {
get { return (B)GetValue(BProperty); }
set { SetValue(BProperty, value); }
}
public BGrid() {
InitializeComponent();
}
}
CGrid.xaml
<UserControl
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
x:Class="wpfStackOverflow.CGrid"
DataContext="{Binding RelativeSource={RelativeSource Self}, Path=C}"
>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition />
</Grid.ColumnDefinitions>
<Label Grid.Column="0" Content="Property"/>
<TextBox Grid.Column="1" Text="{Binding Property}"/>
</Grid>
</UserControl>
CGrid.xaml.cs
public partial class CGrid : UserControl {
static public DependencyProperty CProperty { get; private set; }
static CGrid() {
CProperty = DependencyProperty.Register("C", typeof(C), typeof(CGrid));
}
public C C {
get { return (C)GetValue(CProperty); }
set { SetValue(CProperty, value); }
}
public CGrid() {
InitializeComponent();
}
}
window1.xaml
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:wpfStackOverflow"
x:Class="wpfStackOverflow.Window1"
Width="400"
Height="200"
>
<local:AGroupBox x:Name="aGroupBox" />
</Window>
Window1.xaml.cs
public partial class Window1 : Window {
public Window1() {
InitializeComponent();
aGroupBox.A = new A()
{
Property = "A's Custom Property Value",
B = new B()
{
Property = "B's Custom Property Value"
},
C = new C()
{
Property = "C's Custom Property Value"
}
};
}
}
尝试将以下内容替换为AGroupBox.xaml
<local:BGrid B="{Binding Path=A.B, RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type local:AGroupBox}}}"/>
<local:CGrid C="{Binding Path=A.C, RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type local:AGroupBox}}}"/>
它没有为这两行正确地解析数据上下文,因此没有为B和C寻找合适的位置。
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