判断页面是否有网络

自己定义一个类/** * Copyright (C) 2013-2014 EaseMob Technologies. All rights reserved. * <p> * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * http://www.apache.org/licenses/LICENSE-2.0 * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package com.example.longfei.videodemo.utils;import android.app.ActivityManager;import android.app.ActivityManager.RunningTaskInfo;import android.content.Context;import android.net.ConnectivityManager;import android.net.NetworkInfo;import java.util.List;public class CommonUtils {    /**     * 检测网络是否可用     *     * @param context     * @return     */    public static boolean isNetWorkConnected(Context context) {        if (context != null) {            ConnectivityManager mConnectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);            NetworkInfo mNetworkInfo = mConnectivityManager.getActiveNetworkInfo();            if (mNetworkInfo != null) {                return mNetworkInfo.isAvailable();            }        }        return false;    }    /**     * 检测Sdcard是否存在     *     * @return     */    public static boolean isExitsSdcard() {        if (android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED))            return true;        else            return false;    }    static String getString(Context context, int resId) {        return context.getResources().getString(resId);    }    public static String getTopActivity(Context context) {        ActivityManager manager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);        List<RunningTaskInfo> runningTaskInfos = manager.getRunningTasks(1);        if (runningTaskInfos != null)            return runningTaskInfos.get(0).topActivity.getClassName();        else            return "";    }}

调用类方法

boolean flag = CommonUtils.isNetWorkConnected(getActivity());//有网if (flag) {    initView(view);} else {    Toast.makeText(getActivity(), "当前无网络连接", Toast.LENGTH_SHORT).show();}