调用从 main activity 到片段的异步任务

Question

我有一个异步任务需要在我的 bottomsheet 片段中单击按钮时启动。但是，当我使用

从我的底片片段调用该方法时

  private async void _navigationButton_Click(object sender, EventArgs e)
   {          
       await ((MainActivity)Activity).Routing();
   }

我收到错误：

CS7036 There is no argument given that corresponds to the required formal parameter 'p' of 'MainActivity.Routing(MapPoint)' Maps.

下面的代码是我在主活动中单击地图上的地图点时获取路线的方法。

try
{
    _textToSpeech = new TextToSpeech(this, this, "com.google.android.tts");

    Stop stop0 = new Stop(_startPoint) { Name = "Starting Point" };
    // Stop stop1 = new Stop(_endPoint) { Name = "EndPoint" };

    if (_endPoint == null)
    {
        await _geocoder.ReverseGeocodeAsync(p);
        _endPoint = p;
        RouteTask routeTask = await RouteTask.CreateAsync(_routingUri);
        RouteParameters routingParameters = await routeTask.CreateDefaultParametersAsync();
        List<Stop> stops = new List<Stop> { new Stop(_startPoint), new Stop(_endPoint) };
        routingParameters.SetStops(stops);
        RouteResult result = await routeTask.SolveRouteAsync(routingParameters);

        Route firstRoute = result.Routes.First();

        _routeAheadGraphic = new Graphic(firstRoute.RouteGeometry) { Symbol = new SimpleLineSymbol(SimpleLineSymbolStyle.Solid, System.Drawing.Color.Blue, 4) };

        SimpleLineSymbol(SimpleLineSymbolStyle.Dash, System.Drawing.Color.Red, 2) }; _myMapView.GraphicsOverlays[0].Graphics.Add(_routeAheadGraphic);

        await _myMapView.SetViewpointGeometryAsync(firstRoute.RouteGeometry, 100);

        return;
}

Answer 1

如果Fragment中没有mappoint，可以先在Mainactivity中定义一个public方法，在该方法中调用Routing(mapPoint)。

主要Activity

 public void MyMethod(){
     Routing(mapPoint);
 }

片段

private async void _navigationButton_Click(object sender, EventArgs e)
{          
    await ((MainActivity)Activity).MyMethod();
}

调用从 main activity 到片段的异步任务

Call on an Async Task from main activity to a fragment

c#

xamarin.android

arcgis-runtime

主要Activity

片段