如何在Silverlight中查找可见的DataGrid行？

Question

如何在Silverlight中查找可见的DataGrid行？

Answer 1

I'm not sure what you mean by Visible DataGridRow s but you could get all DataGridRow s that are generated at the moment by finding them in the Visual Tree. This will basically give you all Visible DataGridRow s and probably a few more because of the Virtualization used in the DataGrid

Example

private List<DataGridRow> GetDataGridRows(DataGrid dataGrid)
{
    return GetVisualChildCollection<DataGridRow>(c_dataGrid);            
}

GetVisualChildCollection

public static List<T> GetVisualChildCollection<T>(object parent) where T : FrameworkElement
{
    List<T> visualCollection = new List<T>();
    GetVisualChildCollection(parent as DependencyObject, visualCollection);
    return visualCollection;
}
private static void GetVisualChildCollection<T>(DependencyObject parent, List<T> visualCollection) where T : FrameworkElement
{
    int count = VisualTreeHelper.GetChildrenCount(parent);
    for (int i = 0; i < count; i++)
    {
        DependencyObject child = VisualTreeHelper.GetChild(parent, i);
        if (child is T)
        {
            visualCollection.Add(child as T);
        }
        else if (child != null)
        {
            GetVisualChildCollection(child, visualCollection);
        }
    }
}

Answer 2

The way I've done it is by hooking up to the DataGrid's LoadingRow and UnloadingRow events.

Here's an example

    HashSet<DataGridRow> loadedRows

    private void HandleUnloadingRow(object sender, DataGridRowEventArgs e)
    {
        _loadedRows.Remove(e.Row);
    }

    private void HandleLoadingRow(object sender, DataGridRowEventArgs e)
    {
        _loadedRows.Add(e.Row);
    }