android 判断网络状态

首先需要添加权限：

代码：

package com.test;


import android.app.Activity;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.widget.Toast;


public class NetStateActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

if(isConnectedInternet()){
Toast.makeText(NetStateActivity.this, "Connected", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(NetStateActivity.this, "Disconnected", Toast.LENGTH_SHORT).show();
}
}

private boolean isConnectedInternet(){
ConnectivityManager conManager = (ConnectivityManager)getSystemService(CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = conManager.getActiveNetworkInfo();
if(networkInfo != null){
return networkInfo.isAvailable();
}
return false;
}
}