WPF FlowDocumentScrollViewer会自动滚动到文档底部

Question

我有一个类似于XAML的UserControl：

<Grid>
    <FlowDocumentScrollViewer Name="ProvisionStatusMonitor" Document="{Binding Document}" SourceUpdated="OnSourceUpdated"/>
</Grid>

代码隐藏看起来像这样

    private void OnSourceUpdated(object sender, DataTransferEventArgs e)
    {
        FlowDocumentScrollViewer docViewer = (FlowDocumentScrollViewer) sender;

        var scrollViewer = (ScrollViewer)docViewer.Template
            .FindName("ProvisionStatusMonitor", docViewer);

        scrollViewer.ScrollToEnd();
    }

但这似乎行不通。当文档被更改时，我想这个事件应该被触发，我可以自动滚动到文档的底部。我遗漏了什么？

Answer 1

您可以将PropertyChanged事件处理程序附加到视图中的DataContextChanged处理程序中的视图模型。

假设StatusView是一个包含问题中所示FlowDocumentScrollViewer的UserControl，它可能如下所示：

public StatusView()
{
    InitializeComponent();

    DataContextChanged += StatusViewDataContextChanged;
}

private void StatusViewDataContextChanged(
    object sender, DependencyPropertyChangedEventArgs e)
{
    if (e.OldValue is INotifyPropertyChanged oldViewModel)
    {
        oldViewModel.PropertyChanged -= ViewModelPropertyChanged;
    }

    if (e.NewValue is INotifyPropertyChanged newViewModel)
    {
        newViewModel.PropertyChanged += ViewModelPropertyChanged;
    }
}

private void ViewModelPropertyChanged(
    object sender, PropertyChangedEventArgs e)
{
    if (e.PropertyName == "Document")
    {
        var docViewer = ProvisionStatusMonitor;

        var scrollViewer = (ScrollViewer)docViewer.Template
            .FindName("PART_ContentHost", docViewer);

        scrollViewer.ScrollToEnd();
    }
}