將DataContext設置為XAML中的當前代碼隱藏對象

Question

我正在嘗試將UserControl的DataContext設置為UserControl的代碼隱藏類。 從代碼隱藏方面來看，這很容易做到：

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，我怎樣才能完全從XAML端和UserControl級別執行此操作？ 如果我這樣做，它適用於子節點（並從代碼隱藏中刪除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
        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本身上執行此操作。 我希望這可行：

<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>

但事實並非如此。

Answer 1

DataContext="{Binding Mode=OneWay, RelativeSource={RelativeSource Self}}"

應該管用。

但是，如果在調用InitializeComponent()之前未設置屬性，則WPF綁定機制不知道屬性的值已更改。

為了給你一個快速的想法：

// 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" };
}

如果您正在使用字符串列表，請考慮使用ObservableCollection 。 這將在添加或刪除項目時通知WPF綁定機制。