更改Xamarin.Forms.Maps中缩放按钮(+-)的位置

Question

我想在Xamarin.Forms中更改Zoom button controls (+)(-)在map上的位置。有可能吗？

Answer 1

经过一些研究，我认为没有办法重新定位google地图的默认缩放控件，但正如我们所说的，您可以使用自定义渲染器创建自己的地图控件，因此您可以自定义缩放控件，例如：

<Grid>
    <controls:MapWithMyZoomControl x:Name="map"
          HorizontalOptions="FillAndExpand"
          VerticalOptions="FillAndExpand" />

    <StackLayout Orientation="Vertical">
        <Button Text="Zoom In" Clicked="Zoom_In" />
        <Button Text="Zoom Out" Clicked="Zoom_Out" />
    </StackLayout>
</Grid>

MapWithMyZoomControl：

public class MapWithMyZoomControl : Map
{
    public ZoomState MyZoom
    {
        get { return (ZoomState)GetValue(MyZoomProperty); }
        set { SetValue(MyZoomProperty, value); }
    }

    public static readonly BindableProperty MyZoomProperty =
        BindableProperty.Create(
            propertyName: "MyZoom",
            returnType: typeof(ZoomState),
            declaringType: typeof(MapWithMyZoomControl),
            defaultValue: ZoomState.normal,
            propertyChanged: OnZoomPropertyChanged);

    public static void OnZoomPropertyChanged(BindableObject bindable, object oldValue, object newValue)
    {
    }

    public enum ZoomState
    {
        normal,
        zoomin,
        zoomout
    }
}

渲染器：

public class MapWithMyZoomControlRenderer : MapRenderer, IOnMapReadyCallback
{
    private GoogleMap map;

    public void OnMapReady(GoogleMap googleMap)
    {
        map = googleMap;

        map.UiSettings.ZoomControlsEnabled = false;
    }

    protected override void OnElementChanged(ElementChangedEventArgs<Map> e)
    {
        base.OnElementChanged(e);

        if (e.OldElement != null)
        {
            // Unsubscribe
        }

        if (e.NewElement != null)
        {
            var formsMap = (MapWithMyZoomControl)e.NewElement;

            ((MapView)Control).GetMapAsync(this);
        }
    }

    protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        base.OnElementPropertyChanged(sender, e);
        var element = Element as MapWithMyZoomControl;
        if (e.PropertyName == "MyZoom" && map != null)
        {
            if (element.MyZoom == MapWithMyZoomControl.ZoomState.zoomin)
            {
                map.AnimateCamera(CameraUpdateFactory.ZoomIn());
            }
            else if (element.MyZoom == MapWithMyZoomControl.ZoomState.zoomout)
            {
                map.AnimateCamera(CameraUpdateFactory.ZoomOut());
            }
            element.MyZoom = MapWithMyZoomControl.ZoomState.normal;
        }
    }
}

不要忘了像这样在渲染器中添加程序集：

[assembly: ExportRenderer(typeof(MapWithMyZoomControl), typeof(MapWithMyZoomControlRenderer))]

现在，您可以更改按钮样式和位置。

Answer 2

namespace WD.EMP.APP.Droid.Renderer {
    public class GEMapRenderer: MapRenderer {
        protected override void OnMapReady(Android.Gms.Maps.GoogleMap googleMap) {
            base.OnMapReady(googleMap);
            NativeMap.SetPadding(0, 0, 0, 500);
        }
    }
}

NativeMap.SetPadding(0,0,0,500 );  

通过设置填充谷歌地图可以解决你的问题，在onmapready函数的渲染器文件中放置NativeMap.SetPadding(0,0,0,500 );

Answer 3

您可以只使用padding属性。

<maps:Map
    Padding="0, 0, 0, 20">