Android清除缓存功能来实现
我们都知道在Android的设置->应用程序中能够查看应用程序的相关信息,当中有一个功能是清除缓存。如图:
怎么实现这些功能呢,从Android的setting源代码中能够得到相关信息。
实现例如以下:
Java代码:
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; @Override protected 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() { @Override public 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(); } } }
由于得到缓存信息须要增加android.permission.GET_PACKAGE_SIZE的权限
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-sdk android:minSdkVersion="8" android:targetSdkVersion="17" /> <uses-permission android:name="android.permission.GET_PACKAGE_SIZE"/> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android: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">由于使用在代码中使用了PackageManager的getPackageSizeInfo这个函数。可是这种方法是不正确外公开的函数,全部我们须要使用发射来调用这个函数,在该方法的内部回调了onGetStatsCompleted(PackageStats pStats, boolean succeeded)这种方法,通过该方法的pStats參数能够得到应用的缓存,数据缓存,代码容量缓存,在使用的过程中须要用到系统的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;
最后执行的结果:
源代码地址下载:
http://download.csdn.net/detail/wangbiaohome/8026535
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