Question

我正在引用这个很好的例子：See here

我收到以下错误，但找不到解决方法。请帮忙！将触发NoSuchElementException。在MainActivity中，我按照描述进行操作。在我的Android-Manifest中，我还包括

<uses-library android:name="com.google.android.maps" />

启动应用程序后，很快会出现mapview（灰色图案），然后突然出现强制关闭对话框。

我的 MainActivity ：

public class MainActivity extends MapActivity {



@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    MapView mapView = (MapView) findViewById(R.id.mapview); //or you can declare it directly with the API key
    Route route = directions(new GeoPoint((int)(26.2*1E6),(int)(50.6*1E6)), new GeoPoint((int)(26.3*1E6),(int)(50.7*1E6)));
    RouteOverlay routeOverlay = new RouteOverlay(route, Color.BLUE);
    mapView.getOverlays().add(routeOverlay);

}

private Route directions(final GeoPoint start, final GeoPoint dest) {
    Parser parser;
    String jsonURL = "http://maps.google.com/maps/api/directions/json?";
    final StringBuffer sBuf = new StringBuffer(jsonURL);
    sBuf.append("origin=");
    sBuf.append(start.getLatitudeE6()/1E6);
    sBuf.append(',');
    sBuf.append(start.getLongitudeE6()/1E6);
    sBuf.append("&destination=");
    sBuf.append(dest.getLatitudeE6()/1E6);
    sBuf.append(',');
    sBuf.append(dest.getLongitudeE6()/1E6);
    sBuf.append("&sensor=true&mode=driving");
    parser = new GoogleParser(sBuf.toString());
    Route r =  parser.parse();
    return r;
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}

@Override
protected boolean isRouteDisplayed() {
    // TODO Auto-generated method stub
    return false;
}
}

我的activity_main.xml：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<com.google.android.maps.MapView
    android:id="@+id/mapview" android:layout_width="fill_parent"
    android:layout_height="fill_parent" android:clickable="true"
    android:apiKey="..........................................." />

</RelativeLayout>

Errolog ：

11-19 11:22:17.782: I/MapActivity(10703): Handling network change notification:CONNECTED
11-19 11:22:17.782: E/MapActivity(10703): Couldn't get connection factory client
11-19 11:22:17.822: D/AndroidRuntime(10703): Shutting down VM
11-19 11:22:17.822: W/dalvikvm(10703): threadid=1: thread exiting with uncaught exception (group=0x4001d5a0)
11-19 11:22:17.872: E/AndroidRuntime(10703): FATAL EXCEPTION: main
11-19 11:22:17.872: E/AndroidRuntime(10703): java.util.NoSuchElementException
11-19 11:22:17.872: E/AndroidRuntime(10703):    at java.util.ArrayList$ArrayListIterator.next(ArrayList.java:579)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at com.example.testjsongooglemap.RouteOverlay.redrawPath(RouteOverlay.java:90)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at com.example.testjsongooglemap.RouteOverlay.draw(RouteOverlay.java:60)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at com.google.android.maps.Overlay.draw(Overlay.java:179)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at com.google.android.maps.OverlayBundle.draw(OverlayBundle.java:42)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at com.google.android.maps.MapView.onDraw(MapView.java:530)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.view.View.draw(View.java:7014)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.view.ViewGroup.drawChild(ViewGroup.java:1732)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1459)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.view.ViewGroup.drawChild(ViewGroup.java:1730)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1459)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.view.View.draw(View.java:7017)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.widget.FrameLayout.draw(FrameLayout.java:357)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.view.ViewGroup.drawChild(ViewGroup.java:1732)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1459)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.view.ViewGroup.drawChild(ViewGroup.java:1730)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1459)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.view.View.draw(View.java:7017)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.widget.FrameLayout.draw(FrameLayout.java:357)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:2054)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.view.ViewRoot.draw(ViewRoot.java:1632)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.view.ViewRoot.performTraversals(ViewRoot.java:1335)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.view.ViewRoot.handleMessage(ViewRoot.java:1991)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.os.Handler.dispatchMessage(Handler.java:99)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.os.Looper.loop(Looper.java:150)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at android.app.ActivityThread.main(ActivityThread.java:4385)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at java.lang.reflect.Method.invokeNative(Native Method)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at java.lang.reflect.Method.invoke(Method.java:507)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:849)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:607)
11-19 11:22:17.872: E/AndroidRuntime(10703):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

您要做的是使用directions()将方法AsyncTask放在另一个线程中，因为您无法在UI线程上运行网络方法。另外，使用mapView.invalidate()来刷新（重绘覆盖图）MapView并在绘制后查看路线。

Answer 2

我相信第Route r = parser.parse();行返回一条空路线（即内部没有点）。

要确认，请尝试在上述行之后添加以下内容：

Lod.d("MyApp", "Route size: " + r.getPoints().size());

可能你会得到尺寸0。

如果是这种情况，您需要解释为什么解析器无法处理路径点。

问候。

Answer 3

以下是它的样子：

public class MainActivity extends MapActivity {

MapView mapView = null;
MapController mapController;
double long1 = 50.123*1E6;
double lati1 = 13.123*1E6;
double long2 = 50.221*1E6;
double lati2 = 13.221*1E6;
GeoPoint start, dest;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
     mapView = (MapView) findViewById(R.id.mapview);


     DirectionsTask getDirectionsTask = new DirectionsTask();
     getDirectionsTask.execute(new GeoPoint((int)(long1),(int)(lati1)), new GeoPoint((int)(long2),(int)(lati2)));



}

private class DirectionsTask extends AsyncTask<GeoPoint, Void, Route> {

    protected Route doInBackground(GeoPoint...geoPoints) {
        start = geoPoints[0];
        dest =  geoPoints[1];

           Parser parser;
            String jsonURL = "http://maps.google.com/maps/api/directions/json?";
            final StringBuffer sBuf = new StringBuffer(jsonURL);
            sBuf.append("origin=");
            sBuf.append(start.getLatitudeE6()/1E6);
            sBuf.append(',');
            sBuf.append(start.getLongitudeE6()/1E6);
            sBuf.append("&destination=");
            sBuf.append(dest.getLatitudeE6()/1E6);
            sBuf.append(',');
            sBuf.append(dest.getLongitudeE6()/1E6);
            sBuf.append("&sensor=true&mode=driving");
            Log.v("I came in URL", sBuf.toString());
            parser = new GoogleParser(sBuf.toString());
            Route r =  parser.parse();
            return r;
    }




protected void onPostExecute(Route route) {
    RouteOverlay routeOverlay = new RouteOverlay(route, Color.BLUE);
     mapView.getOverlays().add(routeOverlay);
     mapView.invalidate();
     mapController = mapView.getController();
     mapController.setZoom(14); // Zoom 1 is world view
     mapView.getMapCenter();


}

}

使用Json在Google Maps Mapview中绘制路径

3 个答案: