Android检测网络状态&监听网络变化
网络状态改变、用户信息改变（帐户的钱），第一时间就要想到用观察者模式来实现
广播接收者，简单地把网络的变化通过接口抛出去
package com.qkt.face.et.receiver;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.util.Log;
import com.qkt.face.et.MyApplication;
import com.qkt.face.et.enums.NetworkType;
import com.qkt.face.et.utils.NetworkUtil;
import java.util.ArrayList;
import java.util.List;
public class NetStateChangeReceiver extends BroadcastReceiver {
private static class InstanceHolder {
private static final NetStateChangeReceiver INSTANCE = new NetStateChangeReceiver();
}
private List mObservers = new ArrayList<>();
@Override
public void onReceive(Context context, Intent intent) {
if (ConnectivityManager.CONNECTIVITY_ACTION.equals(intent.getAction())) {
NetworkType networkType = NetworkUtil.getNetworkType(context);
Log.i("NetStateChangeReceiver", networkType.toString());
notifyObservers(networkType);
}
}
public static void registerReceiver(Context context) {
IntentFilter intentFilter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
context.registerReceiver(InstanceHolder.INSTANCE, intentFilter);
}
public static void unRegisterReceiver(Context context) {
context.unregisterReceiver(InstanceHolder.INSTANCE);
}
public static void registerObserver(NetStateChangeObserver observer) {
if (observer == null) {
return;
}
if (!InstanceHolder.INSTANCE.mObservers.contains(observer)) {
InstanceHolder.INSTANCE.mObservers.add(observer);
}
}
public static void unRegisterObserver(NetStateChangeObserver observer) {
if (observer == null) {
return;
}
if (InstanceHolder.INSTANCE.mObservers == null) {
return;
}
InstanceHolder.INSTANCE.mObservers.remove(observer);
}
private void notifyObservers(NetworkType networkType) {
if (networkType == NetworkType.NETWORK_NO) {
for (NetStateChangeObserver observer : mObservers) {
observer.onNetDisconnected();
}
} else {
for (NetStateChangeObserver observer : mObservers) {
observer.onNetConnected(networkType);
}
}
}
}
public enum NetworkType {
NETWORK_WIFI("WiFi"),
NETWORK_4G("4G"),
NETWORK_2G("2G"),
NETWORK_3G("3G"),
NETWORK_UNKNOWN("Unknown"),
NETWORK_NO("No network");
private String desc;
NetworkType(String desc) {
this.desc = desc;
}
@Override
public String toString() {
return desc;
}
}在需要的地方监听网络状态变化(记得销毁时删除监听器)，一般在BaseActivity
public class BaseActivity extends AppCompatActivity implements NetStateChangeObserver {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
NetStateChangeReceiver.registerObserver(this);
registerReceiver();
}
@Override
protected void onDestroy() {
super.onDestroy();
NetStateChangeReceiver.unRegisterObserver(this);
unregisterReceiver();
}
@Override
public void onNetDisconnected() {
ivNet.setImageResource(R.drawable.netError);
}
//设置网络图标
@Override
public void onNetConnected(NetworkType networkType) {
if (networkType.equals(NetworkType.NETWORK_WIFI) ) {
getWifi();
} else {
ivNet.setImageResource(R.drawable.net_eth);
}
}
//获取wifi信号强度
private void getWifi() {
//x心跳包请求成功，获取真实网速，请求失败，网络错误
WifiManager wifi_service = (WifiManager) getContext().getApplicationContext().getSystemService(WIFI_SERVICE);
WifiInfo wifiInfo = wifi_service.getConnectionInfo();
int wStrength = Math.abs(wifiInfo.getRssi());
if (wStrength < 50) {
ivNet.setImageResource(R.drawable.net4);
} else if (49 < wStrength && wStrength < 100) {
ivNet.setImageResource(R.drawable.net3);
} else if (100 < wStrength) {
ivNet.setImageResource(R.drawable.net2);
}
}
}public class NetworkUtil {
private NetworkUtil() {
throw new UnsupportedOperationException("u can't instantiate me...");
}
@RequiresPermission("android.permission.ACCESS_NETWORK_STATE")
private static NetworkInfo getActiveNetworkInfo(Context context) {
ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
return cm.getActiveNetworkInfo();
}
/**
* 获取当前网络类型
* 需添加权限 {@code