Netstateネットワークが接続されているかどうかを確認

package com.wzq.netstatedemo;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        int netType = NetStateUtil.getNetType(MainActivity.this);
        if (netType != -1) {
            initdata();
        }else {
            Toast.makeText(this, "     ", Toast.LENGTH_SHORT).show();
        }


    }

    private void initdata() {
        Toast.makeText(this, "        ", Toast.LENGTH_SHORT).show();
    }
}

package com.wzq.netstatedemo;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;

/**
 * author:Created by WangZhiQiang on 2017-11-01.
 */

class NetStateUtil {

    /**
     *         
     * -1 :   
     *  0 :      ;
     * 1  : wifi  
     * @return
     * @param context      
     */
    public static int getNetType(Context context) {
        int mState = -1;//      
        //  android       ,         ,              
        ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        //NetworkInfo          
        NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
        if(activeNetworkInfo ==null){
            return mState;
        }
        int type = activeNetworkInfo.getType();

        if (type == ConnectivityManager.TYPE_WIFI) {//     wifi  
            mState = 1;
        }else if(type == ConnectivityManager.TYPE_MOBILE ){
            mState = 0;
        }
        return mState;
    }
}