TabHost页和子Activity之间的通讯-阿里云开发者社区

TabHost页和子Activity之间的通讯

2016-05-10 1533

简介：

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TabHost的各个Tab页，都是由activity组成。
现在，某个子Activity中处理数据后，要自动跳转到另外一个Tab页中。这样，需要有个TabHost页和子Activity之间的通讯的机制。

子Activity通知TabHost：
1、通过广播方式
1）在TabHost中定义广播
定义变量
protected MessageBroadcastReceiver myReceiver = null;

在onCreate中注册：
加入receiveBroadcast();

private void receiveBroadcast() {
myReceiver = new MessageBroadcastReceiver();
//Log.d(LOG_TAG, "receiveBroadcast() ::::: " + myReceiver.hashCode());
IntentFilter intentFilter = new IntentFilter("android.intent.action.MAIN");
registerReceiver(myReceiver, intentFilter);
}

在onDestroy中释放广播

if (myReceiver != null)
unregisterReceiver(myReceiver);

MessageBroadcastReceiver类定义:
public class MessageBroadcastReceiver extends BroadcastReceiver {

@Override
public void onReceive(Context context, Intent intent) {
try {
String action = intent.getAction();
if (action.equals("android.intent.action.MAIN")) {
switch (intent.getIntExtra("msg", 0)) {
case Constant.BROADCAST_KEY_TABHOST_CHANGE: {
int tabIndex = intent.getIntExtra("tabIndex", 0);
animateChangeTab(tabIndex);
}
}
}
} catch (Exception e) {
e.printStackTrace();
Log.v(LOG_TAG, e.getMessage());
}
}
}

2）在子Activity中调用
Intent intent = new Intent("android.intent.action.MAIN");
intent.putExtra("msg", Constant.BROADCAST_KEY_TABHOST_CHANGE);
intent.putExtra("tabIndex", 0);
sendBroadcast(intent);


2、通过handler接收消息
1）在TabHost中定义Handler

// 得到主线程的Looper对象
Looper looper = Looper.myLooper();
// 这个myHandler由主线程创建所以它与主线程关联
public MessageHandler msgHandler = new MessageHandler(looper);


private void showMessage(String message) {

// 发送本次信息
msgHandler.removeMessages(0);
Message m = msgHandler.obtainMessage(1, 1, 1, message); // 构造要传递的消息
msgHandler.sendMessage(m); // 发送消息: 系统会自动调用handleMessage 方法来处理消息
}


public class MessageHandler extends Handler {
public MessageHandler(Looper looper) {
super(looper);
}

@Override
public void handleMessage(Message msg) { // 处理消息
switch (msg.what) {
case Constant.BROADCAST_KEY_TABHOST_CHANGE:
int tabIndex = (Integer) msg.obj;
animateChangeTab(tabIndex);
break;
default:
Toast.makeText(getApplicationContext(), msg.obj.toString(),
Toast.LENGTH_SHORT).show();
break;
}
}
}

2）在子Activity中调用

BasketballMainActivity t= (BasketballMainActivity) getParent();
Message message = new Message();
message.what = Constant.BROADCAST_KEY_TABHOST_CHANGE;
message.obj = 0;
t.msgHandler.sendMessage(message);

TabHost通知子Activity：
1、子Activity是活动的
在TabHost中增加
Activity currentActivity = getCurrentActivity();

if (currentActivity instanceof A) {
((A) currentActivity).处理方法XXX;

}

2、子Activity是不是活动的
在子Activity的
@Override
protected void onResume() {
//添加逻辑即可
}