问题描述
我有一个扩展 BroadcastReceiver
的类。收到短信后,我想将信息传递到我的主要活动班级中,以在框中显示文本(附加,如果已经存在文本,则显示文本)。
I have a class which extends BroadcastReceiver
. On receiving a SMS, I would like to pass information to my main activity class to display the text in a box (Append, if already text is present).
public class SmsReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent)
{
Intent i = new Intent(context, MainActivity.class);
i.putExtra("updatedString","Hello");
context.startActivity(i);
}
}
MainActivity.java
MainActivity.java
public class MainActivity extends Activity{
private TextView results;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Bundle extras = getIntent().getExtras();
if(extras!=null){
results = (TextView) findViewById(R.id.results);
results.setVisibility(View.VISIBLE);
results.append(extras.getString("updatedString"));
}
}
我只有一个活动班级( MainActivity.java
)。但是,当我这样做时,我得到一个异常,无法暂停活动。
I have only one activity class (MainActivity.java
). However When i do this I get an exception Unable to pause Activity.
推荐答案
您有以下三种方式:
1)您可以在 MainActivity
中定义广播,如下所示:
在 onCreate()
You have three ways:
1) You can define your broadcast inside your MainActivity
like this:
in onCreate()
registerReceiver(smsReceiver, new IntentFilter(SMS_RECIEVED));
并在
MainActivity
and define smsReciver in
MainActivity
private BroadcastReceiver smsReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
//you can update textBox here
handler.postDelayed(sendUpdatesToUI, 10);
}
};
定义一个可运行的界面来更新UI
define a runnable to update UI
private Runnable sendUpdatesToUI = new Runnable() {
public void run() {
update();
}
};
和更新方法
private void update(String text) {
textView.setText(textView.getText().toString() + text);
}
2)在您的Activity和BroadCastReceiver之间注册接收器
2) Register a receiver between your Activity and BroadCastReceiver
3)使用新的Intent启动您的活动以更新当前打开的活动
3) Start your Activity with new Intent to update current open Activity
Intent intent = new Intent(context, MainActivity.class);
intent.putExtra("Key", "text");
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(intent);
更新:
解释方法2
MainActivity.class
UPDATE :
explain method 2
MainActivity.class
在
onResume()
registerReceiver(broadcastReceiver, new IntentFilter(SmsReceiver.BROADCAST_ACTION));
在
onDestroy()
unregisterReceiver(broadcastReceiver);
本地broadCast(broadcastReceiver,在MainActivity.class中)
local broadCast (broadcastReceiver, in MainActivity.class)
private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
updateUI(intent);
}
};
private void updateUI(Intent intent) {
String text = intent.getStringExtra("key");
textView.setText(textView.getText().toString() + text);
}
SmsReceiver.class
全局属性
SmsReceiver.class
global attribute
public static final String BROADCAST_ACTION = "your.package.name.displayevent";
private final Handler handler = new Handler();
Intent intent;
Context context;
在
onReceive()
handler.removeCallbacks(sendUpdatesToUI);
handler.postDelayed(sendUpdatesToUI, 10);
this.context = context;//you can retrieve context from onReceive argument
this.intent = new Intent(BROADCAST_ACTION);
定义两种方法
private Runnable sendUpdatesToUI = new Runnable() {
public void run() {
display();
}
};
private void display() {
intent.putExtra("key", text);
context.sendBroadcast(intent);
}
这篇关于将Intent从BroadcastReceiver类发送到当前正在运行的活动的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!