重置WPF Datagrid滚动条位置

Question

更改Datagrid的.DataContext属性(到新源)时,将清除所选项目,但保留滚动条位置.为了避免这种情况,我调用.ScrollIntoView(.Item(0),在更改datacontext之后,向上移动滚动条.但是它会在几分之一秒内显示错误的页面,当我在更改datacontext之前滚动到顶部时,我也有同样的问题.

那么如何更改.DataContext并同时重置滚动条位置呢？

编辑:我应该提到我的XAML看起来像这样:

<DataGrid VirtualizingStackPanel.IsVirtualizing="True" VirtualizingStackPanel.VirtualizationMode="Recycling"> 

也许虚拟化是原因.

Answer 1

您是否尝试过呼吁ScrollToTop为ScrollViewer在DataContextChanged仅事件？

<DataGrid VirtualizingStackPanel.IsVirtualizing="True"
          VirtualizingStackPanel.VirtualizationMode="Recycling"
          DataContextChanged="dataGrid_DataContextChanged"
          ...>

private void dataGrid_DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
{
    ScrollViewer scrollViewer = GetVisualChild<ScrollViewer>(dataGrid);
    if (scrollViewer != null)
    {
        scrollViewer.ScrollToTop();
    }
}

GetVisualChild

private static T GetVisualChild<T>(DependencyObject parent) where T : Visual
{
    T child = default(T);

    int numVisuals = VisualTreeHelper.GetChildrenCount(parent);
    for (int i = 0; i < numVisuals; i++)
    {
        Visual v = (Visual)VisualTreeHelper.GetChild(parent, i);
        child = v as T;
        if (child == null)
        {
            child = GetVisualChild<T>(v);
        }
        if (child != null)
        {
            break;
        }
    }
    return child;
}