改变MapControl中的重叠顺序

Question

我需要添加一些元素到MapControl，例如:

<Maps:MapControl HorizontalAlignment="Stretch"  VerticalAlignment="Stretch" Loaded="MapControl_Loaded" x:Name="mymap">
    <Rectangle x:Name="r1" Width="100" Height="100" Fill="Red"/>
    <Rectangle x:Name="r2" Width="20" Height="20" Fill="Green"/>
    <Rectangle x:Name="r3" Width="20" Height="20" Fill="Blue"/>
    <Rectangle x:Name="r4" Width="20" Height="20" Fill="Yellow"/>
    <Rectangle x:Name="r5" Width="20" Height="20" Fill="Purple"/>
</Maps:MapControl>

我通过代码设置矩形的位置:

        MapControl.SetLocation(r1, new Geopoint(new BasicGeoposition() {
            Latitude = 45.6593049969524,
            Longitude = 8.97672694176435
        }));
        MapControl.SetNormalizedAnchorPoint(r1, new Point(0.5, 0.5));
        MapControl.SetLocation(r2, new Geopoint(new BasicGeoposition()
        {
            Latitude = 45.6592821981758,
            Longitude = 8.97627767175436
        }));
        MapControl.SetNormalizedAnchorPoint(r2, new Point(0.5, 0.5));
        MapControl.SetLocation(r3, new Geopoint(new BasicGeoposition()
        {
            Latitude = 45.6589662004262,
            Longitude = 8.97650314494967
        }));
        MapControl.SetNormalizedAnchorPoint(r3, new Point(0.5, 0.5));
        MapControl.SetLocation(r4, new Geopoint(new BasicGeoposition()
        {
            Latitude = 45.6604913715273,
            Longitude = 8.97657556459308
        }));
        MapControl.SetNormalizedAnchorPoint(r4, new Point(0.5, 0.5));
        MapControl.SetLocation(r5, new Geopoint(new BasicGeoposition()
        {
            Latitude = 45.6580915488303,
            Longitude = 8.97816779091954
        }));

矩形从第一个(r1)渲染到最后一个(r5)，因此r5与其他矩形重叠，r4与r3,r2,r1等重叠…

现在我需要添加另一个矩形(r6)，但我想让r6在r1以下:

    Rectangle r6 = new Rectangle();
    r6.Width = 70;
    r6.Height = 70;
    r6.Fill = new SolidColorBrush(Colors.Coral);
    mymap.Children.Insert(0, r6);
    MapControl.SetLocation(r6, new Geopoint(new BasicGeoposition()
    {
        Latitude = 45.6594054121524,
        Longitude = 8.97751081734896
    }));
    MapControl.SetNormalizedAnchorPoint(r6, new Point(0.5, 0.5));

我使用"mymap.Children."插入(0,r6);"代替"Children。添加"来将r6放在第一个位置，但它不起作用，它被渲染为好像它是最后一个元素。

我尝试使用画布。SetZIndex，但它在MapControl上不起作用。

所以问题是，我如何将r6添加到MapControl并将其渲染为第一个元素?

Answer 1

渲染顺序取决于控件添加到MapControl的时间。虽然你在第一个位置插入了矩形(r6)，但它是最后添加的，所以它是首先渲染的。要更改MapControl中XAML控件的呈现顺序，我们需要删除MapControl中的所有控件。并按照正确的顺序重新添加它们，如下所示:

private void myMap_Loaded(object sender, RoutedEventArgs e)
{
    //create a list to save the controls already in MapControl
    var originalChildren = new List<DependencyObject>();
    originalChildren = myMap.Children.ToList();
    //clear the controls
    myMap.Children.Clear();
    Rectangle r6 = new Rectangle();
    r6.Width = 70;
    r6.Height = 70;
    r6.Fill = new SolidColorBrush(Colors.Coral);
    //re-add into MapControl
    originalChildren.Insert(0, r6);
    foreach (var item in originalChildren)
    {
        myMap.Children.Add(item);
    }
    MapControl.SetLocation(r1, new Geopoint(new BasicGeoposition()
    {
        Latitude = 45.6593049969524,
        Longitude = 8.97672694176435
    }));
    MapControl.SetNormalizedAnchorPoint(r1, new Point(0.5, 0.5));
    MapControl.SetLocation(r2, new Geopoint(new BasicGeoposition()
    {
        Latitude = 45.6592821981758,
        Longitude = 8.97627767175436
    }));
    MapControl.SetNormalizedAnchorPoint(r2, new Point(0.5, 0.5));
    MapControl.SetLocation(r3, new Geopoint(new BasicGeoposition()
    {
        Latitude = 45.6589662004262,
        Longitude = 8.97650314494967
    }));
    MapControl.SetNormalizedAnchorPoint(r3, new Point(0.5, 0.5));
    MapControl.SetLocation(r4, new Geopoint(new BasicGeoposition()
    {
        Latitude = 45.6604913715273,
        Longitude = 8.97657556459308
    }));
    MapControl.SetNormalizedAnchorPoint(r4, new Point(0.5, 0.5));
    MapControl.SetLocation(r5, new Geopoint(new BasicGeoposition()
    {
        Latitude = 45.6580915488303,
        Longitude = 8.97816779091954
    }));
    MapControl.SetLocation(r6, new Geopoint(new BasicGeoposition()
    {
        Latitude = 45.6594054121524,
        Longitude = 8.97751081734896
    }));
    MapControl.SetNormalizedAnchorPoint(r6, new Point(0.5, 0.5));
}