第六章自定义有序广播的发送、终止传达和修改广播内容 1.3

1. SendOrderBroadcastActivity:

 1 package com.example.broadcastdemo;
 2 
 3 import android.app.Activity;
 4 import android.content.Intent;
 5 import android.content.IntentFilter;
 6 import android.os.Bundle;
 7 import android.view.View;
 8 
 9 import androidx.annotation.Nullable;
10 
11 public class SendOrderBroadcastActivity extends Activity {
12 
13     private HighLevelReceiver mHighLevelReceiver;
14     private DefaultLevelReceiver mDefaultLevelReceiver;
15     private LowLevelReceiver mLowLevelReceiver;
16 
17     @Override
18     protected void onCreate(@Nullable Bundle savedInstanceState) {
19         super.onCreate(savedInstanceState);
20         setContentView(R.layout.activity_send_order_broadcast);
21 
22         registerBroadcastReceiver();
23     }
24 
25     /**
26      *
27      * @param view
28      */
29     public void sendOrderBroadcast(View view){
30 
31         Intent intent = new Intent();
32         intent.setAction(Constants.ACTION_ORDER_BROADCAST);
33         sendOrderedBroadcast(intent, null);
34     }
35 
36     /**
37      * 注册动态广播
38      */
39     public void registerBroadcastReceiver(){
40         // 分别定义各自的意图过滤器
41         IntentFilter intentFilterHigh = new IntentFilter();
42         IntentFilter intentFilterDefault = new IntentFilter();
43         IntentFilter intentFilterLow = new IntentFilter();
44         intentFilterHigh.addAction(Constants.ACTION_ORDER_BROADCAST);
45         intentFilterDefault.addAction(Constants.ACTION_ORDER_BROADCAST);
46         intentFilterLow.addAction(Constants.ACTION_ORDER_BROADCAST);
47         // 初始化各个广播接收者
48         mHighLevelReceiver = new HighLevelReceiver();
49         mDefaultLevelReceiver = new DefaultLevelReceiver();
50         mLowLevelReceiver = new LowLevelReceiver();
51         // 设置有序等级，范围是-1000~1000，默认是0
52         intentFilterHigh.setPriority(1000);
53         intentFilterDefault.setPriority(0);
54         intentFilterLow.setPriority(-1000);
55         // 注册对应接收者的广播
56         this.registerReceiver(mHighLevelReceiver, intentFilterHigh);
57         this.registerReceiver(mDefaultLevelReceiver, intentFilterDefault);
58         this.registerReceiver(mLowLevelReceiver, intentFilterLow);
59     }
60 }

2. HighLevelReceiver（高级接收者）:

 1 package com.example.broadcastdemo;
 2 
 3 import android.content.BroadcastReceiver;
 4 import android.content.Context;
 5 import android.content.Intent;
 6 import android.util.Log;
 7 
 8 public class HighLevelReceiver extends BroadcastReceiver {
 9     private static final String TAG = "HighLevelReceiver";
10 
11     @Override
12     public void onReceive(Context context, Intent intent) {
13         Log.d(TAG, "high action is -- " + intent.getAction());
14     }
15 }

3. DefaultLevelReceiver(默认接收者，优先值默认为0）:

 1 package com.example.broadcastdemo;
 2 
 3 import android.content.BroadcastReceiver;
 4 import android.content.Context;
 5 import android.content.Intent;
 6 import android.util.Log;
 7 
 8 public class DefaultLevelReceiver extends BroadcastReceiver {
 9 
10     private static final String TAG = "DefaultLevelReceiver";
11 
12     @Override
13     public void onReceive(Context context, Intent intent) {
14         Log.d(TAG, "default action is -- " + intent.getAction());
15     }
16 }

4. LowLevelReceiver:

 1 package com.example.broadcastdemo;
 2 
 3 import android.content.BroadcastReceiver;
 4 import android.content.Context;
 5 import android.content.Intent;
 6 import android.util.Log;
 7 
 8 public class LowLevelReceiver extends BroadcastReceiver {
 9     private static final String TAG = "LowLevelReceiver";
10 
11     @Override
12     public void onReceive(Context context, Intent intent) {
13         Log.d(TAG, "low action is -- " + intent.getAction());
14     }
15 }

5. Constants（存放自定义的常量）:

1 package com.example.broadcastdemo;
2 
3 public class Constants {
4     // 自定义action的名字
5     public static final String ACTION_SEND_MSG = "com.example.broadcastdemo.SEND_MSG";
6     public static final String ACTION_ORDER_BROADCAST = "com.example.broadcastdemo.ORDER_BROADCAST";
7     public static final String KEY_CONTENT = "content";
8 }

6. 输出结果如下：

　　com.example.broadcastdemo D/HighLevelReceiver: high action is -- com.example.broadcastdemo.ORDER_BROADCAST

　　com.example.broadcastdemo D/DefaultLevelReceiver: default action is -- com.example.broadcastdemo.ORDER_BROADCAST

　　com.example.broadcastdemo D/LowLevelReceiver: low action is -- com.example.broadcastdemo.ORDER_BROADCAST

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

7. 终止向下传达与修改传达的内容并下发

　　在上文的基础上，对sendOrderBroadcast增加数据的传输：

 1 /**
 2      * 当按钮被按时，触发该函数以发送广播
 3      * @param view
 4      */
 5     public void sendOrderBroadcast(View view){
 6 
 7         Intent intent = new Intent();
 8         intent.setAction(Constants.ACTION_ORDER_BROADCAST);
 9         // 通过bundle封装数据
10         Bundle bundle = new Bundle();
11         bundle.putCharSequence("content", "我是被发送的广播内容...");
12         /*
13          * @param intent The Intent to broadcast; all receivers matching this
14          * Intent will receive the broadcast.
15          *
16          * @param receiverPermission String naming a permissions that
17          * a receiver must hold in order to receive your broadcast.
18          * If null, no permission is required.
19          *
20          * @param resultReceiver Your own BroadcastReceiver to treat as the final
21          * receiver of the broadcast.
22          *
23          * @param scheduler A custom Handler with which to schedule the
24          * resultReceiver callback; if null it will be scheduled in the Context 's main thread.
25          *
26          * @param initialCode An initial value for the result code.  Often
27          * Activity.RESULT_OK.
28          *
29          * @param initialData An initial value for the result data.  Often
30          * null.
31          *
32          * @param initialExtras An initial value for the result extras.  Often
33          * null.
34          * 有关使用bundle传值和intent的putExtra传值的区别:https://www.cnblogs.com/66it/p/10486029.html
35          */
36         sendOrderedBroadcast(intent, null, null, null, Activity.RESULT_OK, null, bundle );
37 
38     }

　　接着，对HighLevelReceiver添加终止传达或者修改传达内容的代码：

 1 package com.example.broadcastdemo;
 2 
 3 import android.content.BroadcastReceiver;
 4 import android.content.Context;
 5 import android.content.Intent;
 6 import android.os.Bundle;
 7 import android.util.Log;
 8 
 9 public class HighLevelReceiver extends BroadcastReceiver {
10     private static final String TAG = "HighLevelReceiver";
11 
12     @Override
13     public void onReceive(Context context, Intent intent) {
14         Log.d(TAG, "high action is -- " + intent.getAction());
15         // 终止向下传达
16 //        abortBroadcast();
17         // 获取到传入的bundle
18         Bundle resultExtras = getResultExtras(true);
19         // 通过键值来获取内容
20         String content = resultExtras.getCharSequence("content").toString();
21         Log.d(TAG, "content -- " + content);
22         // 修改广播内容
23         resultExtras.putCharSequence("content", "我是被high修改过的广播内容...");
24         // 把修改过的bundle再传到下一个接收者中
25         setResultExtras(resultExtras);
26     }
27 }

　　对于其他的，也要定义变量来接收上一级接收者的广播（DefaultLevelReceiver或者LowLevelReceiver）：

 1 package com.example.broadcastdemo;
 2 
 3 import android.content.BroadcastReceiver;
 4 import android.content.Context;
 5 import android.content.Intent;
 6 import android.os.Bundle;
 7 import android.util.Log;
 8 
 9 public class DefaultLevelReceiver extends BroadcastReceiver {
10 
11     private static final String TAG = "DefaultLevelReceiver";
12 
13     @Override
14     public void onReceive(Context context, Intent intent) {
15         Log.d(TAG, "default action is -- " + intent.getAction());
16         Bundle resultExtras = getResultExtras(true);
17         String content = resultExtras.getCharSequence("content").toString();
18         Log.d(TAG, "content -- " + content);
19     }
20 }

　　运行结果如下：

　　com.example.broadcastdemo D/HighLevelReceiver: high action is -- com.example.broadcastdemo.ORDER_BROADCAST

　　com.example.broadcastdemo D/HighLevelReceiver: content -- 我是被发送的广播内容...

　　com.example.broadcastdemo D/DefaultLevelReceiver: default action is -- com.example.broadcastdemo.ORDER_BROADCAST

　　com.example.broadcastdemo D/DefaultLevelReceiver: content -- 我是被high修改过的广播内容...

　　com.example.broadcastdemo D/LowLevelReceiver: low action is -- com.example.broadcastdemo.ORDER_BROADCAST

　　com.example.broadcastdemo D/LowLevelReceiver: content -- 我是被high修改过的广播内容...

posted on 2021-10-09 14:41 EndlessShw 阅读(123) 评论(0) 编辑收藏举报

第六章 自定义有序广播的发送、终止传达和修改广播内容 1.3

第六章自定义有序广播的发送、终止传达和修改广播内容 1.3