本文将带你了解Android应用开发Android 8.0的缓存大小和缓存清理接口方法，希望本文对大家学Android有所帮助。

获取缓存大小接口

主要这里的方法已经和7.0不兼容了。

import android.app.usage.UsageStats;

import android.app.usage.UsageStatsManager;

import android.content.Context;

import android.content.pm.PackageManager;

import android.os.Process;

import android.os.storage.StorageManager;

import java.io.IOException;

import java.util.ArrayList;

import java.util.Map;

import android.app.usage.StorageStats;

import android.app.usage.StorageStatsManager;

public static long getCacheSizeByAndroidO(Context mContext, String mPackageName)   {

StorageManager storageManager =   (StorageManager)   mContext.getSystemService(Context.STORAGE_SERVICE);

StorageStatsManager storageStatsManager =   (StorageStatsManager)   mContext.getSystemService(Context.STORAGE_STATS_SERVICE);

try {

StorageStats

storageStats =

storageStatsManager.queryStatsForPackage(StorageManager.UUID_DEFAULT,

mPackageName, Process.myUserHandle());

return storageStats.getCacheBytes();

} catch (PackageManager.NameNotFoundException e)   {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

}

return 0L;

}

清除缓存接口

这里的接口和7.0保持一致

PackageManager mPm =   mContext.getPackageManager();

//   need android.permission.DELETE_CACHE_FILES

mPm.deleteApplicationCacheFiles(cacheItem.packageName,   new   IPackageDataObserver.Stub()   {

@Override

public void onRemoveCompleted(final String packageName, final boolean succeeded) throws RemoteException {

///

}

}

});

Andorid   8.0 Setting   模块的源码参考

源码的缓存大小

import com.android.internal.util.Preconditions;

import com.android.settings.utils.AsyncLoader;

import com.android.settingslib.applications.StorageStatsSource;

import com.android.settingslib.applications.StorageStatsSource.AppStorageStats;

import java.io.IOException;

/**

* Fetches the storage stats using the   StorageStatsManager for a given package and user   tuple.

*/

public class FetchPackageStorageAsyncLoader extends AsyncLoader   {

private static final String TAG = "FetchPackageStorage";

private final StorageStatsSource mSource;

private final ApplicationInfo mInfo;

private final   UserHandle   mUser;

@Override

public AppStorageStats loadInBackground()   {

AppStorageStats result =   null;

try {

result =   mSource.getStatsForPackage(mInfo.volumeUuid, mInfo.packageName,   mUser);

} catch (NameNotFoundException | IOException e)   {

Log.w(TAG, "Package may have been removed during   query, failing gracefully", e);

}

return result;

}

========================================================================================

package com.android.settings.applications;

public class AppStorageSettings extends AppInfoWithHeader

@Override

public void onLoadFinished(Loader loader,   AppStorageStats result) {

mSizeController.setResult(result);

updateUiWithSize(result);

}

private void updateUiWithSize(AppStorageStats result)   {

} else {

long codeSize =   result.getCodeBytes();

long cacheSize =   result.getCacheBytes();

long dataSize = result.getDataBytes() - cacheSize;

源码的清理缓存接口

mPm.deleteApplicationCacheFiles

package com.android.settings.applications;

public class AppStorageSettings extends AppInfoWithHeader

implements OnClickListener, Callbacks,   DialogInterface.OnClickListener,

LoaderManager.LoaderCallbacks   {

private static final String TAG = AppStorageSettings.class.getSimpleName();

private ClearCacheObserver   mClearCacheObserver;

@Override

public void onClick(View v) {

// 清理缓存按钮

if (v == mClearCacheButton) {

if (mAppsControlDisallowedAdmin != null && !mAppsControlDisallowedBySystem)   {

RestrictedLockUtils.sendShowAdminSupportDetailsIntent(

getActivity(),   mAppsControlDisallowedAdmin);

return;

} else if (mClearCacheObserver == null)   { // Lazy   initialization of observer

mClearCacheObserver = new ClearCacheObserver();

}

mMetricsFeatureProvider.action(getContext(),

MetricsEvent.ACTION_SETTINGS_CLEAR_APP_CACHE);

// 清理缓存

mPm.deleteApplicationCacheFiles(mPackageName,   mClearCacheObserver);

class ClearCacheObserver extends IPackageDataObserver.Stub {

public void onRemoveCompleted(final String packageName, final boolean succeeded) {

final Message msg =   mHandler.obtainMessage(MSG_CLEAR_CACHE);

msg.arg1 = succeeded ? OP_SUCCESSFUL :   OP_FAILED;

mHandler.sendMessage(msg);

}

}

Android   7.0 的缓存大小接口

PackageManager mPm =   mContext.getPackageManager();

mPm.getPackageSizeInfo(mPackageName, new IPackageStatsObserver.Stub() {

@Override

public void onGetStatsCompleted(PackageStats pStats, boolean succeeded) throws RemoteException {

cacheTotalSize = pStats.cacheSize +   pStats.externalCacheSize;

}

}

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