转自:http://blog.csdn.net/jason0539/article/details/18075293
第一种方法:
遇到一个问题,需要在一个activity中控制另一个acitivity做一些更新,没想到传递handler的方法,通过以下方式解决。
1.在MyAPP中定义属性handler
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package
jason.com;
import
jason.com.MasterActivity.MyHandler;
import
android.app.Application;
/**
* 自己实现Application,实现数据共享
* @author jason
*/
public
class
MyAPP
extends
Application {
// 共享变量
private
MyHandler handler =
null
;
// set方法
public
void
setHandler(MyHandler handler) {
this
.handler = handler;
}
// get方法
public
MyHandler getHandler() {
return
handler;
}
}
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2、在主activity 中给MyAPP的属性handler赋值
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@Override
public
void
onCreate(Bundle savedInstanceState) {
super
.onCreate(savedInstanceState);
setContentView(R.layout.main);
mAPP = (MyAPP) getApplication();
handler =
new
MyHandler();
tv = (TextView) findViewById(R.id.tv);
btn_to = (Button) findViewById(R.id.btn_to);
// 设置监听器
btn_to.setOnClickListener(
new
OnClickListener() {
@Override
public
void
onClick(View v) {
// 设置共享变量
mAPP.setHandler(handler);
// 启动另一个Activity
Intent intent =
new
Intent(MasterActivity.
this
,
ToChangeViewActivity.
class
);
startActivity(intent);
}
});
}
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3、在另一个activity中获取MyAPP中handler进行传值
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protected
void
onCreate(Bundle savedInstanceState) {
super
.onCreate(savedInstanceState);
setContentView(R.layout.show);
mAPP = (MyAPP) getApplication();
// 获得该共享变量实例
mHandler = mAPP.getHandler();
findViewById(R.id.btn_chang).setOnClickListener(
new
OnClickListener() {
@Override
public
void
onClick(View v) {
// 发送消息
mHandler.sendEmptyMessage(CHANGED);
ToChangeViewActivity.
this
.finish();
}
});
}
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第二种方法:
看到作者的这篇文章不错,就转了过来。两个Activity之间可以通过发送广播来控制另外一个activity的UI更新,比如团购APP里:我下了个订单之后,那么我可以通过发送广播通知“我的订单”里面的内容内容自动更新。
再重复一遍我遇到的问题,就是在MainActivity里面打开AnotherActivity去执行一些操作,相应的改变MainActivity里的一些布局或者执行一些动作,最开始想到的就是把MainActivity的Handler直接传给AnotherActivity,好像不可行,就有了这篇和上一篇文章。
上一篇方案一是通过重写application来在两个activity之间共享Handler的,今天这个方案是通过广播机制解决本来想要通过传递handler来实现的功能,算是Activity之间传递Handler问题的变通方案,
其实很简单,就是Broadcast的应用,替换了原来想要通过共享handler解决的思路。
代码如下:
MainActivity:
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package
jason.broadcastinsteadofhanlderdemo;
import
android.app.Activity;
import
android.content.BroadcastReceiver;
import
android.content.Context;
import
android.content.Intent;
import
android.content.IntentFilter;
import
android.os.Bundle;
import
android.view.View;
import
android.view.View.OnClickListener;
import
android.widget.Button;
import
android.widget.TextView;
public
class
MainActivity
extends
Activity {
TextView textView;
Button sButton;
@Override
protected
void
onCreate(Bundle savedInstanceState) {
super
.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = (TextView) findViewById(R.id.show);
sButton = (Button) findViewById(R.id.startAnother);
sButton.setOnClickListener(
new
OnClickListener() {
@Override
public
void
onClick(View v) {
// TODO Auto-generated method stub
startActivity(
new
Intent(MainActivity.
this
,AnotherActivity.
class
));
}
});
IntentFilter filter =
new
IntentFilter(AnotherActivity.action);
registerReceiver(broadcastReceiver, filter);
}
BroadcastReceiver broadcastReceiver =
new
BroadcastReceiver() {
@Override
public
void
onReceive(Context context, Intent intent) {
// TODO Auto-generated method stub
textView.setText(intent.getExtras().getString(
"data"
));
}
};
protected
void
onDestroy() {
unregisterReceiver(broadcastReceiver);
};
}
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AnotherActivity:
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package
jason.broadcastinsteadofhanlderdemo;
import
android.app.Activity;
import
android.content.Intent;
import
android.os.Bundle;
import
android.view.View;
import
android.view.View.OnClickListener;
import
android.widget.Button;
public
class
AnotherActivity
extends
Activity {
public
static
final
String action =
"jason.broadcast.action"
;
Button update;
@Override
protected
void
onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super
.onCreate(savedInstanceState);
setContentView(R.layout.another);
update = (Button) findViewById(R.id.updateMain);
update.setOnClickListener(
new
OnClickListener() {
@Override
public
void
onClick(View v) {
// TODO Auto-generated method stub
Intent intent =
new
Intent(action);
intent.putExtra(
"data"
,
"yes i am data"
);
sendBroadcast(intent);
finish();
}
});
}
}
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