meta-data的使用

在manifest里面我们经常会发现有几个meta-data标签，他们常被用来配置参数常量。

例如：<meta-data android:name="HIAPK_RECDID" android:value="2238872"/>

<meta-data android:name="UMENG_APPKEY" android:value="4dfb66ee431fe371d9000063" />

<meta-data android:name="appkey" android:value="110000" />

这三个标签是写在application下面的。

meta-data还可以出现在activity，receiver，service标签中。

一，在application中

<!-- app -->  

1.         <meta-data android:name="application_name" android:value="application_value" />  

<!-- app --><meta-data android:name="application_name" android:value="application_value" />

 

获取meta-data

ApplicationInfo appInfo = this.getPackageManager().getApplicationInfo(  

1.                     getPackageName(), PackageManager.GET_META_DATA);  
2.             String msg = appInfo.metaData.getString("application_name");  

ApplicationInfo appInfo = this.getPackageManager().getApplicationInfo(getPackageName(), PackageManager.GET_META_DATA);String msg = appInfo.metaData.getString("application_name");

 

二，在activity中

<!-- Activity -->  

1.         <activity android:name=".MyActivity" android:label="@string/app_name">  
2.             <intent-filter>  
3.                 <action android:name="android.intent.action.MAIN" />  
4.                 <category android:name="android.intent.category.LAUNCHER" />  
5.             </intent-filter>  
6.             <meta-data android:name="activity_name" android:value="activity_value" />  
7.         </activity>  

<!-- Activity --><activity android:name=".MyActivity" android:label="@string/app_name"><intent-filter><action android:name="android.intent.action.MAIN" /><category android:name="android.intent.category.LAUNCHER" /></intent-filter><meta-data android:name="activity_name" android:value="activity_value" /></activity>

获取meta-data

ActivityInfo actInfo = mContext.getPackageManager().getActivityInfo(  

1.                     getComponentName(), PackageManager.GET_META_DATA);  
2.             String msg = actInfo.metaData.getString("activity_name");  

ActivityInfo actInfo = mContext.getPackageManager().getActivityInfo(getComponentName(), PackageManager.GET_META_DATA);String msg = actInfo.metaData.getString("activity_name");

三，在service中

1.         <service android:name=".MyService">  
2.             <meta-data android:name="service_name" android:value="service_value" />  
3.         </service>  

<!-- 服务 --><service android:name=".MyService"><meta-data android:name="service_name" android:value="service_value" /></service>

获取meta-data

ComponentName cn = new ComponentName(this, MyService.class);  

1.         try {  
2.             ServiceInfo serInfo = this.getPackageManager().getServiceInfo(cn,  
3.                     PackageManager.GET_META_DATA);  
4.         } catch (NameNotFoundException e) {  
5.             e.printStackTrace();  
6.         }  
7.         String msg = serInfo.metaData.getString("service_name");  

ComponentName cn = new ComponentName(this, MyService.class);try {ServiceInfo serInfo = this.getPackageManager().getServiceInfo(cn,PackageManager.GET_META_DATA);} catch (NameNotFoundException e) {e.printStackTrace();}String msg = serInfo.metaData.getString("service_name");

四，在receiver中，也就是广播接收者（拨打电话的时候会看到toast消息）
<receiver android:name=".MyReceiver">  

1.             <meta-data android:name="receiver_name" android:value="receiver_value" />  
2.             <intent-filter>  
3.                 <action android:name="android.intent.action.PHONE_STATE" />  
4.             </intent-filter>  
5.         </receiver>  

<receiver android:name=".MyReceiver"><meta-data android:name="receiver_name" android:value="receiver_value" /><intent-filter><action android:name="android.intent.action.PHONE_STATE" /></intent-filter></receiver>

获取meta-data

if (TextUtils.equals("android.intent.action.PHONE_STATE", intent  

1.                 .getAction())) {  
2.             ComponentName cn = new ComponentName(context, MyReceiver.class);  
3.             try {  
4.                 ActivityInfo info = context.getPackageManager().getReceiverInfo(cn,  
5.                         PackageManager.GET_META_DATA);  
6.             } catch (NameNotFoundException e) {  
7.                 e.printStackTrace();  
8.             }  
9.             String msg = info.metaData.getString("receiver_name");  
10.             // 打电话测试即可  
11.             Toast.makeText(context, msg, Toast.LENGTH_SHORT).show();  
12.         }