Android判断设备网络连接状态及判断连接方式的方法

/** * 检测网络是否连接 * @return */ private boolean checkNetworkState() {   boolean flag = false;   //得到网络连接信息   manager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);    //去进行判断网络是否连接   if (manager.getActiveNetworkInfo() != null) {     flag = manager.getActiveNetworkInfo().isAvailable();   }   if (!flag) {     setNetwork();   } else {     isNetworkAvailable();   }   return flag;}/*** 网络未连接时，调用设置方法*/private void setNetwork(){   Toast.makeText(this, "wifi is closed!", Toast.LENGTH_SHORT).show();   AlertDialog.Builder builder = new AlertDialog.Builder(this);   builder.setIcon(R.drawable.ic_launcher);   builder.setTitle("网络提示信息");   builder.setMessage("网络不可用，如果继续，请先设置网络！");   builder.setPositiveButton("设置", new OnClickListener() {     @Override     public void onClick(DialogInterface dialog, int which) {       Intent intent = null;       /**       * 判断手机系统的版本！如果API大于10 就是3.0+       * 因为3.0以上的版本的设置和3.0以下的设置不一样，调用的方法不同       */       if (android.os.Build.VERSION.SDK_INT > 10) {         intent = new Intent(android.provider.Settings.ACTION_WIFI_SETTINGS);       } else {         intent = new Intent();         ComponentName component = new ComponentName(             "com.android.settings",             "com.android.settings.WirelessSettings");         intent.setComponent(component);         intent.setAction("android.intent.action.VIEW");       }       startActivity(intent);     }   });   builder.setNegativeButton("取消", new OnClickListener() {     @Override     public void onClick(DialogInterface dialog, int which) {     }   });   builder.create();   builder.show();}/*** 网络已经连接，然后去判断是wifi连接还是GPRS连接* 设置一些自己的逻辑调用*/private void isNetworkAvailable(){   State gprs = manager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState();  State wifi = manager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState();  if(gprs == State.CONNECTED || gprs == State.CONNECTING){    Toast.makeText(this, "wifi is open! gprs", Toast.LENGTH_SHORT).show();  }  //判断为wifi状态下才加载广告，如果是GPRS手机网络则不加载！  if(wifi == State.CONNECTED || wifi == State.CONNECTING){    Toast.makeText(this, "wifi is open! wifi", Toast.LENGTH_SHORT).show();    loadAdmob();  }}