从AlertDialog按钮切换活动

Question

我正在研究基于地图的应用程序。比方说，我有三个类：MapsActivity，MyItemizedOverlay & GetDirectionActivity。在MyItemizedOverlay中，我想在单击肯定对话框按钮后切换到GetDirectionActivity。 ActiveDialog放在onTap方法下，这样我就可以得到GeoPoint。对于这一点，我做了什么： 在ItemizedOverlay类：

@Override 
public boolean onTap(GeoPoint p, MapView mapView) { 
    // TODO Auto-generated method stub 
    int lat = p.getLatitudeE6(); 
    int lot = p.getLongitudeE6(); 
    AlertDialog.Builder dialog = new AlertDialog.Builder(mContext); 
    dialog.setTitle("Confirmation"); 
    dialog.setMessage("Confirm this as end point ?"); 
    dialog.setPositiveButton("Yes", new DialogInterface.OnClickListener() { 

     @Override 
     public void onClick(DialogInterface dialog, int arg1) { 
      // TODO Auto-generated method stub 
      Intent intent = new Intent(mContext, GetDestination.class); 
      startActivity(intent); 
     } 
    }); 
    dialog.setNegativeButton("No", null); 
    dialog.show(); 
    return true ; 
      } 

这里IDE显示，我在startActivity（意向）线错误。 我已经试过了也： 在MyItemizedOverlay类：

@Override 
public boolean onTap(GeoPoint p, MapView mapView) { 
      return super.onTap(p, mapView); } 

在MapsActivity类：

GeoPoint point2 = null ; 
      confirmationOverlay.onTap(point2, mapView) ; 
      int latt = point.getLatitudeE6() ; 
      int longt = point.getLongitudeE6(); 
      final int endpointArray [] = {latt , longt}; 
      if(some condition to show the alert dialog after tapping) 
      { 
       AlertDialog.Builder dialog = new AlertDialog.Builder(MapsActivity.this); 
       dialog.setTitle("Confirmation"); 
       dialog.setMessage("Confirm this location as end point ?"); 
       dialog.setPositiveButton("Yes", new DialogInterface.OnClickListener() { 

        @Override 
        public void onClick(DialogInterface dialog, int arg1) { 
         // TODO Auto-generated method stub 
         Intent intent = new Intent(MapsActivity.this,GetDestination.class); 
         intent.putExtra("geopoint" , endpointArray); 
         startActivity(intent); 
        } 
       }); 
       dialog.setNegativeButton("No", new DialogInterface.OnClickListener() { 
        @Override 
        public void onClick(DialogInterface dialog, int arg1) { 

        } 
       }); 
       dialog.show(); 
      } 

对于if语句什么样的条件下可以使用吗？如果我将它设置为lat> 0，则alertdialog不会在地图上点击而出现。 我知道这是非常愚蠢的，但因为我是新的都在Android & java，我希望你们会考虑它。请帮忙 ！

Answer 1

论ItemizedOverlay类把你的OnTap中的方法：

AlertDialog dialog = new AlertDialog.Builder(MapsActivity.context).create(); 
      dialog.setTitle("Confirmation"); 
      dialog.setMessage("Confirm this location as end point ?"); 

    dialog.setButton(DialogInterface.BUTTON_POSITIVE,"Yes", new DialogInterface.OnClickListener() { 
     public void onClick(DialogInterface dialog, int which) { 
         // TODO Auto-generated method stub 

    Intent intent = new Intent(MapsActivity.context, GetDestination.class); 
         //you must put your map activity  
          MapsActivity.context.startActivity(intent); 


         } 
        }); 


       dialog.show();