将 DataContext 设置为 XAML 中的当前代码隐藏对象
Setting the DataContext to the current code-behind object in XAML
我正在尝试将我的 UserControl 的 DataContext 设置为 UserControl 的代码隐藏 class。从代码隐藏端做起来真的很容易:
public partial class OHMDataPage : UserControl
{
public StringList Stuff { get; set; }
public OHMDataPage ()
{
InitializeComponent();
DataContext = this;
}
}
<UserControl 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"
x:Class="LCDHardwareMonitor.Pages.OHMDataPage">
<ScrollViewer>
<ListBox ItemsSource="{Binding Stuff}" />
</ScrollViewer>
</UserControl>
但是我怎样才能完全从 XAML 端和 UserControl 级别执行此操作?如果我这样做(并从代码隐藏中删除 DataContext = this;
),它将在子节点上工作:
<UserControl 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"
x:Class="LCDHardwareMonitor.Pages.OHMDataPage">
<ScrollViewer
DataContext="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=UserControl}}">
<ListBox ItemsSource="{Binding Stuff}" />
</ScrollViewer>
</UserControl>
我真的很想了解如何在 UserControl 本身上执行此操作。我希望它能起作用:
<UserControl 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"
x:Class="LCDHardwareMonitor.Pages.OHMDataPage"
DataContext="{Binding RelativeSource={RelativeSource Mode=Self}}">
<ScrollViewer>
<ListBox ItemsSource="{Binding Stuff}" />
</ScrollViewer>
</UserControl>
但事实并非如此。
DataContext="{Binding Mode=OneWay, RelativeSource={RelativeSource Self}}"
应该可以。
但是如果在调用 InitializeComponent()
之前未设置您的属性,WPF 绑定机制不知道您的 属性 的值已更改。
给你一个快速的想法:
// the binding should work
public StringList Stuff { get; set; }
public Constructor()
{
Stuff = new StringList { "blah", "blah", "foo", "bar" };
InitializeComponent();
}
// the binding won't work
public StringList Stuff { get; set; }
public Constructor()
{
InitializeComponent();
Stuff = new StringList { "blah", "blah", "foo", "bar" };
}
如果您使用的是字符串列表,请考虑改用 ObservableCollection
。这将在添加或删除项时通知 WPF 绑定机制。
我正在尝试将我的 UserControl 的 DataContext 设置为 UserControl 的代码隐藏 class。从代码隐藏端做起来真的很容易:
public partial class OHMDataPage : UserControl
{
public StringList Stuff { get; set; }
public OHMDataPage ()
{
InitializeComponent();
DataContext = this;
}
}
<UserControl 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"
x:Class="LCDHardwareMonitor.Pages.OHMDataPage">
<ScrollViewer>
<ListBox ItemsSource="{Binding Stuff}" />
</ScrollViewer>
</UserControl>
但是我怎样才能完全从 XAML 端和 UserControl 级别执行此操作?如果我这样做(并从代码隐藏中删除 DataContext = this;
),它将在子节点上工作:
<UserControl 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"
x:Class="LCDHardwareMonitor.Pages.OHMDataPage">
<ScrollViewer
DataContext="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=UserControl}}">
<ListBox ItemsSource="{Binding Stuff}" />
</ScrollViewer>
</UserControl>
我真的很想了解如何在 UserControl 本身上执行此操作。我希望它能起作用:
<UserControl 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"
x:Class="LCDHardwareMonitor.Pages.OHMDataPage"
DataContext="{Binding RelativeSource={RelativeSource Mode=Self}}">
<ScrollViewer>
<ListBox ItemsSource="{Binding Stuff}" />
</ScrollViewer>
</UserControl>
但事实并非如此。
DataContext="{Binding Mode=OneWay, RelativeSource={RelativeSource Self}}"
应该可以。
但是如果在调用 InitializeComponent()
之前未设置您的属性,WPF 绑定机制不知道您的 属性 的值已更改。
给你一个快速的想法:
// the binding should work
public StringList Stuff { get; set; }
public Constructor()
{
Stuff = new StringList { "blah", "blah", "foo", "bar" };
InitializeComponent();
}
// the binding won't work
public StringList Stuff { get; set; }
public Constructor()
{
InitializeComponent();
Stuff = new StringList { "blah", "blah", "foo", "bar" };
}
如果您使用的是字符串列表,请考虑改用 ObservableCollection
。这将在添加或删除项时通知 WPF 绑定机制。