从事安卓有两年多了，对广播的认识却非常少，平时用到广播最多的莫过于监听系统的网络变化，我在本文中主要是讲解自己对于广播应用的一种思想，如果对于广播还不是很熟悉的童鞋们可以参考以下这个链http://www.cnblogs.com/trinea/archive/2012/11/09/2763182.html
下面就以网络监听为例子进行讲解。
1、自定义广播
这里在onReceive里面进行回调处理，通过NetworkCallback回调给注册监听的页面。
ANDROID_NET_CHANGE_ACTION：广播IntentFilter的action
ObjectsHolder:内部用ArrayList实现的多对象持有管理类(详情见下)
public class NetworkReceiver extends BroadcastReceiver
{
private final static String ANDROID_NET_CHANGE_ACTION = "com.king.CONNECTIVITY_CHANGE";
private static BroadcastReceiver sReceiver;
private static IObjectsHolder sObjectsHolder = new ObjectsHolder<>();
@Override
public void onReceive(Context context, Intent intent)
{
sReceiver = this;
String action = intent.getAction();
if (ConnectivityManager.CONNECTIVITY_ACTION.equals(action) || ANDROID_NET_CHANGE_ACTION.equals(action))
{
final NetworkType type = getNetworkType(context);
sObjectsHolder.foreach(new IterateCallback()
{
@Override
public boolean next(int i, NetworkCallback item, Iterator it)
{
item.onNetworkChanged(type);
return false;
}
});
}
}
public static BroadcastReceiver getReceiver()
{
if (sReceiver == null)
{
sReceiver = new NetworkReceiver();
}
return sReceiver;
}
/**
* 发送网络检测广播
*
* @param context
*/
public static void sendBroadcast(Context context)
{
Intent intent = new Intent();
intent.setAction(ANDROID_NET_CHANGE_ACTION);
context.sendBroadcast(intent);
}
/**
* 注册广播
*
* @param context
*/
public static void registerReceiver(Context context)
{
IntentFilter filter = new IntentFilter();
filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
filter.addAction(ANDROID_NET_CHANGE_ACTION);
context.getApplicationContext().registerReceiver(getReceiver(), filter);
}
/**
* 取消注册广播
*
* @param context
*/
public static void unregisterReceiver(Context context)
{
if (sReceiver != null)
{
try
{
context.getApplicationContext().unregisterReceiver(sReceiver);
} catch (Exception e)
{
}
}
}
/**
* 添加回调
*
* @param callback
*/
public static void addCallback(NetworkCallback callback)
{
sObjectsHolder.add(callback);
}
/**
* 移除回调
*
* @param callback
*/
public static void removeCallback(NetworkCallback callback)
{
sObjectsHolder.remove(callback);
}
/**
* 获得ConnectivityManager对象
*
* @param context
* @return
*/
public static ConnectivityManager getConnectivityManager(Context context)
{
ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
return manager;
}
/**
* 网络是否可用
*
* @param context
* @return
*/
public static boolean isNetworkConnected(Context context)
{
ConnectivityManager manager = getConnectivityManager(context);
NetworkInfo info = manager.getActiveNetworkInfo();
if (info != null)
{
return info.isConnected();
} else
{
return false;
}
}
/**
* wifi是否可用
*
* @param context
* @return
*/
public static boolean isWifiConnected(Context context)
{
ConnectivityManager manager = getConnectivityManager(context);
NetworkInfo networkInfo = manager.getActiveNetworkInfo();
if (networkInfo == null)
{
return false;
} else
{
return ConnectivityManager.TYPE_WIFI == networkInfo.getType();
}
}
/**
* 获得网络类型
*
* @param context
* @return
*/
public static NetworkType getNetworkType(Context context)
{
ConnectivityManager manager = getConnectivityManager(context);
NetworkInfo networkInfo = manager.getActiveNetworkInfo();
if (networkInfo == null)
{
return NetworkType.None;
} else
{
int type = networkInfo.getType();
if (type == ConnectivityManager.TYPE_MOBILE)
{
return NetworkType.Mobile;
} else if (type == ConnectivityManager.TYPE_WIFI)
{
return NetworkType.Wifi;
} else
{
return NetworkType.None;
}
}
}
public enum NetworkType
{
/**
* wifi网络
*/
Wifi,
/**
* 移动数据网络
*/
Mobile,
/**
* 无网络
*/
None
}
public interface NetworkCallback
{
/**
* 网络变化监听
*
* @param type
*/
void onNetworkChanged(NetworkType type);
}
}
2、创建接口和ObjectsHolder类
一个内部用ArrayList实现的多对象持有管理类
public interface IObjectsHolder
{
/**
* @Description 添加对象
* @param object
*/
void add(T object);
/**
* @Description 移除对象
* @param object
*/
boolean remove(T object);
/**
*
* @Description 是否已经包含了该对象
* @param object
*/
boolean contains(T object);
/**
* @Description 对象个数
*/
int size();
/**
* @Description 清空对象
*/
void clear();
/**
* @Description 遍历对象
*/
boolean foreach(IterateCallback callback);
/**
* @Description 倒序遍历对象
*/
boolean foreachReverse(IterateCallback callback);
}
public class ObjectsHolder implements IObjectsHolder
{
private List mListObject = new ArrayList<>();
@Override
public void add(T object)
{
if (object == null)
{
return;
}
if (!mListObject.contains(object))
{
mListObject.add(object);
}
}
@Override
public boolean remove(T object)
{
if (object == null)
{
return false;
}
return mListObject.remove(object);
}
@Override
public boolean contains(T object)
{
if (object == null)
{
return false;
}
return mListObject.contains(object);
}
@Override
public int size()
{
return mListObject.size();
}
@Override
public void clear()
{
mListObject.clear();
}
@Override
public boolean foreach(IterateCallback callback)
{
return CollectionUtil.foreach(mListObject,callback);
}
@Override
public boolean foreachReverse(IterateCallback callback)
{
return CollectionUtil.foreachReverse(mListObject,callback);
}
}
3、在程序入口处进行注册
public class App extends Application
{
private static App sInstance;
public static App getApplication()
{
return sInstance;
}
@Override
public void onCreate()
{
super.onCreate();
sInstance = this;
init();
}
private void init()
{
NetworkReceiver.registerReceiver(this);
}
@Override
public void onTerminate()
{
NetworkReceiver.unregisterReceiver(this);
super.onTerminate();
}
}
4、在BaseActivity实现接口并提供方法给子类调用
public class BaseActivity extends AppCompatActivity implements NetworkReceiver.NetworkCallback
{
@Override
protected void onCreate(@Nullable Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
init();
}
private void init()
{
NetworkReceiver.addCallback(this);
}
@Override
protected void onDestroy()
{
NetworkReceiver.removeCallback(this);
super.onDestroy();
}
@Override
public void onNetworkChanged(NetworkReceiver.NetworkType type)
{
}
public class MainActivity extends BaseActivity
{
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
public void onNetworkChanged(NetworkReceiver.NetworkType type)
{
//此处因为为测试机没有SIM卡，如在开发中可以改成mobil
if (type == NetworkReceiver.NetworkType.Wifi)
{
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage("当前处于数据网络下，会耗费较多流量，是否继续？");
builder.setCancelable(false);
builder.setNegativeButton("取消", new DialogInterface.OnClickListener()
{
@Override
public void onClick(DialogInterface dialog, int which)
{
}
});
builder.setPositiveButton("确定", new DialogInterface.OnClickListener()
{
@Override
public void onClick(DialogInterface dialog, int which)
{
}
});
builder.show();
}
super.onNetworkChanged(type);
}
}
具体的demo请查看https://github.com/BingoKingCoding/NetworkMonitor。
谢谢支持。