加载类时警报对话框侦听器出错

Question

我正在使用android项目。现在我正在创建一个自定义的覆盖类。在这个课程中，我在警告对话框监听器上遇到了问题。我无法在侦听器中加载任何意图。我该怎么办？这是我的代码..

import java.util.ArrayList;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.drawable.Drawable;
import android.view.MotionEvent;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.ItemizedOverlay;
import com.google.android.maps.MapView;
import com.google.android.maps.OverlayItem;

/**
 * Class used to place marker or any overlay items on Map
 * */
public class AddItemizedOverlay extends ItemizedOverlay<OverlayItem> {

       private ArrayList<OverlayItem> mapOverlays = new ArrayList<OverlayItem>();

       private Context context;

       public AddItemizedOverlay(Drawable defaultMarker) {
            super(boundCenterBottom(defaultMarker));
       }

       public AddItemizedOverlay(Drawable defaultMarker, Context context) {
            this(defaultMarker);
            this.context = context;
       }

       @Override
       public boolean onTouchEvent(MotionEvent event, MapView mapView)
       {   

           if (event.getAction() == 1) {
               GeoPoint geopoint = mapView.getProjection().fromPixels(
                   (int) event.getX(),
                   (int) event.getY());
               // latitude
               double lat = geopoint.getLatitudeE6() / 1E6;
               // longitude
               double lon = geopoint.getLongitudeE6() / 1E6;
               //Toast.makeText(context, "Lat: " + lat + ", Lon: "+lon, Toast.LENGTH_SHORT).show();
           }
           return false;
       } 

       @Override
       protected OverlayItem createItem(int i) {
          return mapOverlays.get(i);
       }

       @Override
       public int size() {
          return mapOverlays.size();
       }

       @Override
       protected boolean onTap(int index) {
         OverlayItem item = mapOverlays.get(index);
         AlertDialog.Builder dialog = new AlertDialog.Builder(this.context);
         dialog.setTitle(item.getTitle());
         dialog.setMessage(item.getSnippet());
         dialog.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {

                startActivity(new Intent(AddItemizedOverlay.this,SinglePlaceActivity.class));
            }
         })
            .setNegativeButton("No",new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog,int id) {
                    // if this button is clicked, just close
                    // the dialog box and do nothing
                    dialog.cancel();
//                  MainActivity.this.finish();
                }
            });
         dialog.show();
         return true;
       }

       public void addOverlay(OverlayItem overlay) {
          mapOverlays.add(overlay);
       }

       public void populateNow(){
           this.populate();
       }

    }

并出现如下错误

Answer 1

使用Context开始活动。

Intent intent = new Intent(context, RosettaActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(intent);

Answer 2

new Intent(Context, Class)“的第一个参数应该是一个上下文对象，是从Context派生的AddItemizedOverlay吗？