Java 从AlertDialog按钮切换活动

我正在开发一个基于地图的应用程序。比如说，我有三个类：MapsActivity、MyItemizedOverlay和GetDirectionActivity。在MyItemizeOverlay中，我想在单击肯定对话框按钮后切换到GetDirectionActivity。ActiveDialog被放置在onTap方法下，这样我就可以得到地质点。为此，我所做的： 在ItemizeOverlay类中：

@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 ; 
            }

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

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();
            } 

这里IDE显示我在startActivity（intent）行中有一个错误。 我也试过： 在MyItemizeOverlay类中：

@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 ; 
            }

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

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();
            } 

在MapsActivity类中：

@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 ; 
            }

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

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，我可以使用哪种条件？如果我将其设置为lat>0，则会显示alertdialog，而不点击地图。

---

我知道这很愚蠢，但是因为我在Android和java都是新手，希望你们能考虑一下。请帮忙

在ItemizeOverlay类中的OnTap方法上放置：

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();

---

谢谢你的回复。我刚刚查看了你的个人资料，发现你所问或回答的所有问题都与谷歌地图有关。看起来，您正在开发一个地图应用程序。法希姆。ahmed1988@gmail.com这是我的通讯地址。如果你愿意，可以和我联系。在联系人上有一个地图极客对我来说太棒了。无论如何，谢谢。：-）欢迎！：）当然，为什么不呢如果您需要地图方面的帮助，可以与我联系，否则我会与您联系。：）