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
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;
}
}
2、在主activity 中给MyAPP的属性handler赋值
@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);
}
});
}
3、在另一个activity中获取MyAPP中handler进行传值
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();
}
});
}
第二种方法
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。
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:
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);
};
}
AnotherActivity:
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();
}
});
}
}