C# 继承的DataContext-绑定不起作用

以下情况：我得到了一个基类，它提供了一个小框架，用于使用装饰器创建模态对话框

        <Border Grid.Row="0" Background="{DynamicResource InputAdornerHeaderBackground}" BorderThickness="0,0,0,1" CornerRadius="0">
            <TextBlock HorizontalAlignment="Stretch" VerticalAlignment="Stretch" TextWrapping="Wrap" Text="{Binding Header}"
                           FontSize="{DynamicResource InputAdornerHeaderFontSize}" Foreground="{DynamicResource InputAdornerHeaderForeground}"
                           FontWeight="{DynamicResource InputAdornerHeaderFontWeight}" Margin="8" />
        </Border>

        <Border Grid.Row="1" BorderThickness="1,0,1,1" BorderBrush="{DynamicResource InputAdornerBorderBrush}" CornerRadius="0">
            <ContentControl ContentTemplate="{Binding InputControlTemplate}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
        </Border>
    </Grid>
</ContentTemplate>

基类有一个DataTemplate类型的属性，它包含实际的输入方案（所有类型的输入都是可能的），还有一个object属性，它包含映射模型（模板将其输入值绑定到的模型类）

        <Border Grid.Row="0" Background="{DynamicResource InputAdornerHeaderBackground}" BorderThickness="0,0,0,1" CornerRadius="0">
            <TextBlock HorizontalAlignment="Stretch" VerticalAlignment="Stretch" TextWrapping="Wrap" Text="{Binding Header}"
                           FontSize="{DynamicResource InputAdornerHeaderFontSize}" Foreground="{DynamicResource InputAdornerHeaderForeground}"
                           FontWeight="{DynamicResource InputAdornerHeaderFontWeight}" Margin="8" />
        </Border>

        <Border Grid.Row="1" BorderThickness="1,0,1,1" BorderBrush="{DynamicResource InputAdornerBorderBrush}" CornerRadius="0">
            <ContentControl ContentTemplate="{Binding InputControlTemplate}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
        </Border>
    </Grid>
</ContentTemplate>

因为我想重用装饰器，所以我让它有一个ContentControl，anon有一个实际对话框设计的ContentTemplate。对话框的设计包含一个ContentControl，其模板绑定到adorner类中的属性。当然，装饰器ContentControl的DataContext设置为自身

        <Border Grid.Row="0" Background="{DynamicResource InputAdornerHeaderBackground}" BorderThickness="0,0,0,1" CornerRadius="0">
            <TextBlock HorizontalAlignment="Stretch" VerticalAlignment="Stretch" TextWrapping="Wrap" Text="{Binding Header}"
                           FontSize="{DynamicResource InputAdornerHeaderFontSize}" Foreground="{DynamicResource InputAdornerHeaderForeground}"
                           FontWeight="{DynamicResource InputAdornerHeaderFontWeight}" Margin="8" />
        </Border>

        <Border Grid.Row="1" BorderThickness="1,0,1,1" BorderBrush="{DynamicResource InputAdornerBorderBrush}" CornerRadius="0">
            <ContentControl ContentTemplate="{Binding InputControlTemplate}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
        </Border>
    </Grid>
</ContentTemplate>

现在，嵌入式ContentControl（在设计中）生成DataTemplate并显示（在当前情况下）一个文本框。此文本框现在应绑定到模型。因此，我将adorner设计模板的DataContext重新用于实际的输入模板。我是这样做的：

        <Border Grid.Row="0" Background="{DynamicResource InputAdornerHeaderBackground}" BorderThickness="0,0,0,1" CornerRadius="0">
            <TextBlock HorizontalAlignment="Stretch" VerticalAlignment="Stretch" TextWrapping="Wrap" Text="{Binding Header}"
                           FontSize="{DynamicResource InputAdornerHeaderFontSize}" Foreground="{DynamicResource InputAdornerHeaderForeground}"
                           FontWeight="{DynamicResource InputAdornerHeaderFontWeight}" Margin="8" />
        </Border>

        <Border Grid.Row="1" BorderThickness="1,0,1,1" BorderBrush="{DynamicResource InputAdornerBorderBrush}" CornerRadius="0">
            <ContentControl ContentTemplate="{Binding InputControlTemplate}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
        </Border>
    </Grid>
</ContentTemplate>

装饰器的控件模板

        <Border Grid.Row="0" Background="{DynamicResource InputAdornerHeaderBackground}" BorderThickness="0,0,0,1" CornerRadius="0">
            <TextBlock HorizontalAlignment="Stretch" VerticalAlignment="Stretch" TextWrapping="Wrap" Text="{Binding Header}"
                           FontSize="{DynamicResource InputAdornerHeaderFontSize}" Foreground="{DynamicResource InputAdornerHeaderForeground}"
                           FontWeight="{DynamicResource InputAdornerHeaderFontWeight}" Margin="8" />
        </Border>

        <Border Grid.Row="1" BorderThickness="1,0,1,1" BorderBrush="{DynamicResource InputAdornerBorderBrush}" CornerRadius="0">
            <ContentControl ContentTemplate="{Binding InputControlTemplate}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
        </Border>
    </Grid>
</ContentTemplate>

装饰器属性

        <Border Grid.Row="0" Background="{DynamicResource InputAdornerHeaderBackground}" BorderThickness="0,0,0,1" CornerRadius="0">
            <TextBlock HorizontalAlignment="Stretch" VerticalAlignment="Stretch" TextWrapping="Wrap" Text="{Binding Header}"
                           FontSize="{DynamicResource InputAdornerHeaderFontSize}" Foreground="{DynamicResource InputAdornerHeaderForeground}"
                           FontWeight="{DynamicResource InputAdornerHeaderFontWeight}" Margin="8" />
        </Border>

        <Border Grid.Row="1" BorderThickness="1,0,1,1" BorderBrush="{DynamicResource InputAdornerBorderBrush}" CornerRadius="0">
            <ContentControl ContentTemplate="{Binding InputControlTemplate}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
        </Border>
    </Grid>
</ContentTemplate>

public sealed class TextInputModel
{
    public string Text { get; set; }
}

    public DataTemplate InputControlTemplate
    {
        get { return _inputControlTemplate; }
        private set
        {
            if (Equals(value, _inputControlTemplate)) return;
            _inputControlTemplate = value;
            OnPropertyChanged();
        }
    }

    public object InputMapping
    {
        get { return _inputMapping; }
        private set
        {
            if (Equals(value, _inputMapping)) return;
            _inputMapping = value;
            OnPropertyChanged();
        }
    }

仅供参考：在创建装饰器时，将动态实例化模型。它不会被设置两次。这一定是一个有约束力的问题

        <Border Grid.Row="0" Background="{DynamicResource InputAdornerHeaderBackground}" BorderThickness="0,0,0,1" CornerRadius="0">
            <TextBlock HorizontalAlignment="Stretch" VerticalAlignment="Stretch" TextWrapping="Wrap" Text="{Binding Header}"
                           FontSize="{DynamicResource InputAdornerHeaderFontSize}" Foreground="{DynamicResource InputAdornerHeaderForeground}"
                           FontWeight="{DynamicResource InputAdornerHeaderFontWeight}" Margin="8" />
        </Border>

        <Border Grid.Row="1" BorderThickness="1,0,1,1" BorderBrush="{DynamicResource InputAdornerBorderBrush}" CornerRadius="0">
            <ContentControl ContentTemplate="{Binding InputControlTemplate}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
        </Border>
    </Grid>
</ContentTemplate>

模板显示正确。我看到并可以在文本框中输入内容，但一旦我获取模型，所有属性都是默认的（“”）。它确实工作了一两次，但不知何故，设计上的改变显然使它失去了功能

        <Border Grid.Row="0" Background="{DynamicResource InputAdornerHeaderBackground}" BorderThickness="0,0,0,1" CornerRadius="0">
            <TextBlock HorizontalAlignment="Stretch" VerticalAlignment="Stretch" TextWrapping="Wrap" Text="{Binding Header}"
                           FontSize="{DynamicResource InputAdornerHeaderFontSize}" Foreground="{DynamicResource InputAdornerHeaderForeground}"
                           FontWeight="{DynamicResource InputAdornerHeaderFontWeight}" Margin="8" />
        </Border>

        <Border Grid.Row="1" BorderThickness="1,0,1,1" BorderBrush="{DynamicResource InputAdornerBorderBrush}" CornerRadius="0">
            <ContentControl ContentTemplate="{Binding InputControlTemplate}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
        </Border>
    </Grid>
</ContentTemplate>

我不明白这里有什么干扰，因为从我的观点来看，所有的设置都应该正确。我检查了DataTemplate的上下文：它是实际的模型类。但是，文本框输入不会更新属性

        <Border Grid.Row="0" Background="{DynamicResource InputAdornerHeaderBackground}" BorderThickness="0,0,0,1" CornerRadius="0">
            <TextBlock HorizontalAlignment="Stretch" VerticalAlignment="Stretch" TextWrapping="Wrap" Text="{Binding Header}"
                           FontSize="{DynamicResource InputAdornerHeaderFontSize}" Foreground="{DynamicResource InputAdornerHeaderForeground}"
                           FontWeight="{DynamicResource InputAdornerHeaderFontWeight}" Margin="8" />
        </Border>

        <Border Grid.Row="1" BorderThickness="1,0,1,1" BorderBrush="{DynamicResource InputAdornerBorderBrush}" CornerRadius="0">
            <ContentControl ContentTemplate="{Binding InputControlTemplate}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
        </Border>
    </Grid>
</ContentTemplate>

编辑：

---

出于某种原因，似乎是附加的属性导致了此问题。但它为什么要干预？它不会覆盖DataContext，是吗？

而且它总是以最简单的方式失败：UpdateSourceTrigger。当然，这个默认设置为“FocusLost”，因为文本框不会失去焦点，所以它永远不会更新。很难确定它何时随机设置为nothing或（“”）。而且它总是以最简单的方式失败：UpdateSourceTrigger。当然，这个默认设置为“FocusLost”，因为文本框不会失去焦点，所以它永远不会更新。当它随机设置为nothing或（“”）时，很难发现。

        <Border Grid.Row="0" Background="{DynamicResource InputAdornerHeaderBackground}" BorderThickness="0,0,0,1" CornerRadius="0">
            <TextBlock HorizontalAlignment="Stretch" VerticalAlignment="Stretch" TextWrapping="Wrap" Text="{Binding Header}"
                           FontSize="{DynamicResource InputAdornerHeaderFontSize}" Foreground="{DynamicResource InputAdornerHeaderForeground}"
                           FontWeight="{DynamicResource InputAdornerHeaderFontWeight}" Margin="8" />
        </Border>

        <Border Grid.Row="1" BorderThickness="1,0,1,1" BorderBrush="{DynamicResource InputAdornerBorderBrush}" CornerRadius="0">
            <ContentControl ContentTemplate="{Binding InputControlTemplate}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
        </Border>
    </Grid>
</ContentTemplate>