WPF學習筆記（5）：兩個DataGrid的滾動條實現同步滾動

效果：兩個DataGrid的滾動條實現同步滾動。

代碼參考了博客園chuncn的文章《.net中同步多個ScrollViewer滾動的四種方法》，原文是針對ListBox的。現改為針對DataGrid，略微作了修改，代碼以水平滾動條為例。

原文地址：https://www.cnblogs.com/chuncn/archive/2011/10/08/2202175.html

實現方法：

方法一：利用DependencyProperty類的RegisterAttached方法，在屬性系統上註冊附加屬性，並將滾動條屬性值HorizontalOffset通過註冊屬性關聯到一個方法。

ScrollViewer sv1, sv2;

private void Window_Loaded(object sender, RoutedEventArgs e)
{
    //分別獲取兩個DataGrid的ScrollViewer
    sv1 = VisualTreeHelper.GetChild(VisualTreeHelper.GetChild(this.DataGrid1, 0), 0) as ScrollViewer;
    sv2 = VisualTreeHelper.GetChild(VisualTreeHelper.GetChild(this.DataGrid2, 0), 0) as ScrollViewer;

    //將滾動條屬性值HorizontalOffset關聯到OnScrollChanged1方法
    var offsetChangeListener = DependencyProperty.RegisterAttached("ListenerOffset1", typeof(object), typeof(UserControl), new PropertyMetadata(OnScrollChanged1));
    var binding = new Binding("HorizontalOffset") { Source = sv1 };
    sv1.SetBinding(offsetChangeListener, binding);

    offsetChangeListener = DependencyProperty.RegisterAttached("ListenerOffset2", typeof(object), typeof(UserControl), new PropertyMetadata(OnScrollChanged2));
    binding = new Binding("HorizontalOffset") { Source = sv2 };
    sv2.SetBinding(offsetChangeListener, binding);
}

public void OnScrollChanged1(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
    double a = (double)e.NewValue;  //獲取滾動條位置變化後的屬性值
    sv2.ScrollToHorizontalOffset(a);
}

public void OnScrollChanged2(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
    double a = (double)e.NewValue;
    sv1.ScrollToHorizontalOffset(a);
}

方法二：利用滾動條的ScrollChanged事件，同步兩個滾動條的位置。

ScrollViewer sv1, sv2;

private void Window_Loaded(object sender, RoutedEventArgs e)
{
    //分別獲取兩個DataGrid的ScrollViewer
    sv1 = VisualTreeHelper.GetChild(VisualTreeHelper.GetChild(this.DataGrid1, 0), 0) as ScrollViewer;
    sv2 = VisualTreeHelper.GetChild(VisualTreeHelper.GetChild(this.DataGrid2, 0), 0) as ScrollViewer;

    //關聯ScrollChanged事件
    sv1.ScrollChanged += new ScrollChangedEventHandler(sv1_ScrollChanged);
    sv2.ScrollChanged += new ScrollChangedEventHandler(sv2_ScrollChanged);
}

void sv1_ScrollChanged(object sender, ScrollChangedEventArgs e)
{
    sv2.ScrollToHorizontalOffset(sv1.HorizontalOffset);
}

void sv2_ScrollChanged(object sender, ScrollChangedEventArgs e)
{
    sv1.ScrollToHorizontalOffset(sv2.HorizontalOffset);
}