实现 代码如下
package Android.HelloAndroid;import android.app.Activity;import android.app.AlertDialog;import android.content.Context;import android.os.Bundle;import android.widget.TextView;import android.net.ConnectivityManager;import android.net.NetworkInfo;import android.net.NetworkInfo.State;public class Hello extends Activity {/** Called when the activity is first created. */@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);TextView tv = new TextView(this);tv.setText("检测网络状态");setContentView(tv);checkNetworkInfo();goodNet();}public boolean goodNet(){ConnectivityManager manager = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);NetworkInfo networkinfo = manager.getActiveNetworkInfo();if (networkinfo == null || !networkinfo.isAvailable()) {new AlertDialog.Builder(this).setMessage("没有可以使用的网络").setPositiveButton("Ok", null).show();return false;}new AlertDialog.Builder(this).setMessage("网络正常可以使用").setPositiveButton("Ok", null).show();return true;}private void checkNetworkInfo(){ConnectivityManager conMan = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);//mobile 3G Data NetworkState mobile = conMan.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState();new AlertDialog.Builder(this).setMessage(mobile.toString()).setPositiveButton("3G", null).show();//显示3G网络连接状态State wifi = conMan.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState();new AlertDialog.Builder(this).setMessage(wifi.toString()).setPositiveButton("WIFI", null).show();//显示wifi网络连接状态}}
需要注意:
根据Android的安全机制，在使用ConnectivityManager时，必须在AndroidManifest.xml中添加<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> 否则无法获得系统的许可。
