android中判断网络是否连接

在android中，如何监测网络的状态呢，这个有的时候也是十分重要的，方法如下：

public class ConnectionDetector {
	
	private Context _context;
	
	public ConnectionDetector(Context context){
		this._context = context;
	}

	public boolean isConnectingToInternet(){
		ConnectivityManager connectivity = (ConnectivityManager) _context.getSystemService(Context.CONNECTIVITY_SERVICE);
		  if (connectivity != null) 
		  {
			  NetworkInfo[] info = connectivity.getAllNetworkInfo();
			  if (info != null) 
				  for (int i = 0; i < info.length; i++) 
					  if (info[i].getState() == NetworkInfo.State.CONNECTED)
					  {
						  return true;
					  }

		  }
		  return false;
	}

调用：

ConnectionDetector cd = new ConnectionDetector(getApplicationContext()); 
  
Boolean isInternetPresent = cd.isConnectingToInternet(); //