网络判断

package com.bwie.connectivitymanagerdemo;import android.content.Context;import android.content.DialogInterface;import android.net.ConnectivityManager;import android.net.NetworkInfo;import android.os.Bundle;import android.support.v7.app.AlertDialog;import android.support.v7.app.AppCompatActivity;import android.widget.Toast;public class MainActivity extends AppCompatActivity {    private ConnectivityManager connectivityManager;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        //获得网络状态管理器        connectivityManager = (ConnectivityManager) this.getSystemService(Context.CONNECTIVITY_SERVICE);        NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();//得到当前活跃的网络        //boolean isActive = activeNetworkInfo.isAvailable();//得到网络状态        if(activeNetworkInfo != null){//表示有网络            //得到wifi网络的状态            NetworkInfo.State state = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState();            if(NetworkInfo.State.CONNECTED == state){//当前是wifi                Toast.makeText(this,"wifi网络",Toast.LENGTH_SHORT).show();            }else{                Toast.makeText(this,"移动网络",Toast.LENGTH_SHORT).show();            }            //得到移动网络状态            NetworkInfo.State state2 = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState();            if(NetworkInfo.State.CONNECTED == state2){//当前是移动网络                new AlertDialog.Builder(this)                        .setTitle("选择")                        .setIcon(R.mipmap.ic_launcher)                        .setMessage("当前处于移动数据，请在wifi在使用！")                        .setPositiveButton("土豪访问",new AlertDialog.OnClickListener(){                            @Override                            public void onClick(DialogInterface dialog, int which) {                                //编写网络请求代码                            }                        })                        .setNegativeButton("停止访问",null)                        .setNeutralButton("中立按钮",null)                        .show();            }        }else{            Toast.makeText(this,"无网络，请检查",Toast.LENGTH_SHORT).show();        }    }}