android 监听GPS是否打开跳转到设置GPS

监听GPS
权限：
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

主程序代码以及注释：

<span style="white-space:pre"> </span>/**
     * 监听GPS
     */
    private void initGPS() {
        LocationManager locationManager = (LocationManager) this
                .getSystemService(Context.LOCATION_SERVICE);
        // 判断GPS模块是否开启，如果没有则开启
        if (!locationManager
                .isProviderEnabled(android.location.LocationManager.GPS_PROVIDER)) {
            Toast.makeText(TrainDetailsActivity.this, "请打开GPS",
                    Toast.LENGTH_SHORT).show();
            AlertDialog.Builder dialog = new AlertDialog.Builder(this);
            dialog.setMessage("请打开GPS");
            dialog.setPositiveButton("确定",
                    new android.content.DialogInterface.OnClickListener() {

                        @Override
                        public void onClick(DialogInterface arg0, int arg1) {

                            // 转到手机设置界面，用户设置GPS
                            Intent intent = new Intent(
                                    Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                            startActivityForResult(intent, 0); // 设置完成后返回到原来的界面

                        }
                    });
            dialog.setNeutralButton("取消", new android.content.DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface arg0, int arg1) {
                    arg0.dismiss();
                }
            } );
            dialog.show();
        } else {
            // 弹出Toast
//          Toast.makeText(TrainDetailsActivity.this, "GPS is ready",
//                  Toast.LENGTH_LONG).show();
//          // 弹出对话框
//          new AlertDialog.Builder(this).setMessage("GPS is ready")
//                  .setPositiveButton("OK", null).show();
        }
    }