简单的Andr​​oid广播不显示敬酒 [英] Simple Android Broadcast does not show toast

问题描述

我只是想创造机器人的活动简单的广播，但它不工作。

I'm just trying to create a simple broadcast in Androids activity but its not working.

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    Intent i = new Intent("android.intent.action.UMS_CONNECTED"); 

    IntentFilter filter = new IntentFilter();
    filter.addAction("android.intent.action.UMS_CONNECTED");

    receiver = new BroadcastReceiver() {
      @Override
      public void onReceive(Context context, Intent intent) {
          Toast.makeText(getApplicationContext(), "connected", Toast.LENGTH_LONG).show();
      }
    };

    registerReceiver(receiver, filter);


        }
    }

中的XML

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="usb.usbd"
      android:versionCode="1"
      android:versionName="1.0">
       <uses-feature android:name="android.hardware.usb.host" />
    <uses-sdk android:minSdkVersion="12" />    

    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".UsbddActivity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
             <intent-filter>
      <action android:name="android.intent.action.UMS_CONNECTED" />
      <action android:name="android.intent.action.UMS_DISCONNECTED" />
                        </intent-filter>
        </activity>

    </application>
</manifest>

的屏幕显示我的Xoom的，但敬酒不显示。 Xoom的是通过USB连接的，所以应该显示敬酒/

The screen shows on my Xoom but the toast does not display. The Xoom is connected through the USB so it should display the toast/

推荐答案

您无法启动对话框（且不应推出吐司）从在 广播接收器。相反，有广播接收器启动该做了另一个组件（活动/服务等）。要显示吐司只是让另一个活动并调用它，或作出方法上的电流活动显示它并调用。接收器的整个想法是，你做的尽可能少的内部的onReceive 和摆脱，它的接线，它不是你做的工作。

You can't launch a dialog (and shouldn't launch a toast) from within a BroadcastReceiver. Instead have the BroadcastReceiver launch another component (Activity/Service, etc) that does something. TO show a Toast just make another Activity and invoke it, or make a method on your current Activity that shows it and call that. The entire idea of a receiver is that you do as little as possible inside onReceive and get out, it's wiring, it's not where you do work.

<一个href=\"http://developer.android.com/reference/android/content/BroadcastReceiver.html#onReceive%28android.content.Context,%20android.content.Intent%29\"相对=nofollow>广播接收器的JavaDoc

的当广播接收器接收一个​​Intent广播时调用此方法。在此期间，您可以使用广播接收器的其他方法来查看/修改当前结果值。该功能通常被称为它的进程的主线程中，所以你永远不应该在它执行长时间运行的操作（有10秒的超时，系统考虑要阻挡的接收器和一个候选人被杀害之前允许的话） 。你不能在你的实现的onReceive（）的启动弹出式对话框。的

您不能在执行的onReceive的推出弹出式对话框（）

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