我們都知道在Android的設置->應用程序中能夠查看應用程序的相關信息，當中有一個功能是清除緩存。

如圖：

怎么實現這些功能呢，從Android的setting源代碼中能夠得到相關信息。

實現例如以下：

Java代碼：

package com.wang.clearcache;import java.lang.reflect.Method; import android.os.Bundle; import android.os.RemoteException; import android.app.Activity; import android.content.pm.IPackageStatsObserver; import android.content.pm.PackageManager; import android.content.pm.PackageStats;public class MainActivity extends Activity {private PackageManager pm;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);pm = getPackageManager();//反射try {Method method = PackageManager.class.getMethod("getPackageSizeInfo", new Class[]{String.class,IPackageStatsObserver.class});method.invoke(pm, new Object[]{"com.wang.clearcache",new IPackageStatsObserver.Stub() {@Overridepublic void onGetStatsCompleted(PackageStats pStats, boolean succeeded)throws RemoteException {long cachesize = pStats.cacheSize;long codesize = pStats.codeSize;long datasize = pStats.dataSize;System.out.println("cachesize:"+ cachesize);System.out.println("codesize:"+ codesize);System.out.println("datasize"+ datasize);}}});} catch (Exception e) {e.printStackTrace();}} }

由于得到緩存信息須要增加android.permission.GET_PACKAGE_SIZE的權限

Androidmainifest.xml

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"package="com.wang.clearcache"android:versionCode="1"android:versionName="1.0" ><uses-sdkandroid:minSdkVersion="8"android:targetSdkVersion="17" /><uses-permission android:name="android.permission.GET_PACKAGE_SIZE"/><applicationandroid:allowBackup="true"android:icon="@drawable/ic_launcher"android:label="@string/app_name"android:theme="@style/AppTheme" ><activityandroid:name="com.wang.clearcache.MainActivity"android:label="@string/app_name" ><intent-filter><action android:name="android.intent.action.MAIN" /><category android:name="android.intent.category.LAUNCHER" /></intent-filter></activity></application></manifest></pre><pre name="code" class="java">由于使用在代碼中使用了PackageManager的getPackageSizeInfo這個函數。可是這種方法是不正確外公開的函數，全部我們須要使用發射來調用這個函數，在該方法的內部回調了onGetStatsCompleted(PackageStats pStats, boolean succeeded)這種方法，通過該方法的pStats參數能夠得到應用的緩存，數據緩存，代碼容量緩存，在使用的過程中須要用到系統的aidl文件

IPackageStatsObserver：

/* ** ** Copyright 2007, The Android Open Source Project ** ** Licensed under the Apache License, Version 2.0 (the "License"); ** you may not use this file except in compliance with the License. ** You may obtain a copy of the License at ** ** http://www.apache.org/licenses/LICENSE-2.0 ** ** Unless required by applicable law or agreed to in writing, software ** distributed under the License is distributed on an "AS IS" BASIS, ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ** See the License for the specific language governing permissions and ** limitations under the License. */package android.content.pm;import android.content.pm.PackageStats; /*** API for package data change related callbacks from the Package Manager.* Some usage scenarios include deletion of cache directory, generate* statistics related to code, data, cache usage(TODO)* {@hide}*/ oneway interface IPackageStatsObserver {void onGetStatsCompleted(in PackageStats pStats, boolean succeeded); }

PackageStats：

/* //device/java/android/android/view/WindowManager.aidl ** ** Copyright 2007, The Android Open Source Project ** ** Licensed under the Apache License, Version 2.0 (the "License"); ** you may not use this file except in compliance with the License. ** You may obtain a copy of the License at ** ** http://www.apache.org/licenses/LICENSE-2.0 ** ** Unless required by applicable law or agreed to in writing, software ** distributed under the License is distributed on an "AS IS" BASIS, ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ** See the License for the specific language governing permissions and ** limitations under the License. */package android.content.pm;parcelable PackageStats;

最后執行的結果：

源代碼地址下載：

http://download.csdn.net/detail/wangbiaohome/8026535

版權聲明：本文博客原創文章，博客，未經同意，不得轉載。

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