以编程方式清除 Android 应用程序中的缓存

Question

以编程方式清除 android 应用程序中的缓存的正确方法是什么。我已经在使用以下代码，但它看起来不适合我

@Override
protected void onDestroy() {
    // TODO Auto-generated method stub
    super.onDestroy();
    clearApplicationData();
}

public void clearApplicationData() {
    File cache = getCacheDir();
    File appDir = new File(cache.getParent());
    if (appDir.exists()) {
        String[] children = appDir.list();
        for (String s : children) {
            if (!s.equals("lib")) {
                deleteDir(new File(appDir, s));
                Log.i("EEEEEERRRRRRROOOOOOORRRR", "**************** File /data/data/APP_PACKAGE/" + s + " DELETED *******************");
            }
        }
    }
}

public static boolean deleteDir(File dir) {
    if (dir != null && dir.isDirectory()) {
        String[] children = dir.list();
        for (int i = 0; i < children.length; i++) {
            boolean success = deleteDir(new File(dir, children[i]));
            if (!success) {
                return false;
            }
        }
    }

    return dir.delete();
}

Answer 1

如果您正在寻找自己应用程序的删除缓存，那么只需删除您的缓存目录即可！

public static void deleteCache(Context context) {
    try {
        File dir = context.getCacheDir();
        deleteDir(dir);
    } catch (Exception e) { e.printStackTrace();}
}

public static boolean deleteDir(File dir) {
    if (dir != null && dir.isDirectory()) {
        String[] children = dir.list();
        for (int i = 0; i < children.length; i++) {
            boolean success = deleteDir(new File(dir, children[i]));
            if (!success) {
                return false;
            }
        }
        return dir.delete();
    } else if(dir!= null && dir.isFile()) {
        return dir.delete();
    } else {
        return false;
    }
}

Answer 2

Kotlin 有一个单行代码

context.cacheDir.deleteRecursively()

Answer 3

来自 dhams 的答案是正确的（经过多次编辑），但是正如对代码的多次编辑所显示的那样，很难编写正确且健壮的代码来自己删除目录（带有子目录）。所以我强烈建议使用Apache Commons IO，或者其他可以为你做这件事的API：

import org.apache.commons.io.FileUtils;

...

// Delete local cache dir (ignoring any errors):
FileUtils.deleteQuietly(context.getCacheDir());

PS：如果你使用 context.getExternalCacheDir() 返回的目录，也要删除它。

为了能够使用 Apache Commons IO，请将其添加到您的 build.gradle 文件中的 dependencies 部分：

compile 'commons-io:commons-io:2.4'

Answer 4

我认为您应该将clearApplicationData() 放在super.OnDestroy(). 之前

您的应用在关闭后无法处理任何方法。

Answer 5

试试这个

@Override
protected void onDestroy() {
    // TODO Auto-generated method stub
    super.onDestroy();
    clearApplicationData();
}

public void clearApplicationData() {
    File cache = getCacheDir();
    File appDir = new File(cache.getParent());
    if (appDir.exists()) {
        String[] children = appDir.list();
        for (String s : children) {
            if (!s.equals("lib")) {
                deleteDir(new File(appDir, s));
                Log.i("EEEEEERRRRRROOOOOOORRRR", "**************** File /data/data/APP_PACKAGE/" + s + " DELETED *******************");
            }
        }
    }
}

public static boolean deleteDir(File dir) {
    if (dir != null && dir.isDirectory()) {
        String[] children = dir.list();
        int i = 0;
        while (i < children.length) {
            boolean success = deleteDir(new File(dir, children[i]));
            if (!success) {
                return false;
            }
            i++;
        }
    }

    assert dir != null;
    return dir.delete();
}

Answer 6

如果你使用的是 kotlin，那么：

context.cacheDir.deleteRecursively()

Answer 7

如果您使用的是 Android Studio 4.4.2

getCacheDir().delete();

Answer 8

我不确定，但我也播下了这段代码。 这条鳕鱼会更快，在我看来它也很简单。 只需获取您的应用程序缓存目录并删除目录中的所有文件

public boolean clearCache() {
    try {

        // create an array object of File type for referencing of cache files   
        File[] files = getBaseContext().getCacheDir().listFiles();

        // use a for etch loop to delete files one by one
        for (File file : files) {

             /* you can use just [ file.delete() ] function of class File
              * or use if for being sure if file deleted
              * here if file dose not delete returns false and condition will
              * will be true and it ends operation of function by return 
              * false then we will find that all files are not delete
              */
             if (!file.delete()) {
                 return false;         // not success
             }
        }

        // if for loop completes and process not ended it returns true   
        return true;      // success of deleting files

    } catch (Exception e) {}

    // try stops deleting cache files
    return false;       // not success 
}

通过getBaseContext().getCacheDir().listFiles()获取File数组中的所有缓存文件 然后通过file.delet()方法循环一个一个地删除

Answer 9

将此代码放入MainActivity的onStop()方法中

@Override
protected void onStop() {
    super.onStop();
    AppUtils.deleteCache(getApplicationContext());
}

public class AppUtils {
    public static void deleteCache(Context context) {
        try {
            File dir = context.getCacheDir();
            deleteDir(dir);
        } catch (Exception e) {}
    }

    public static boolean deleteDir(File dir) {
        if (dir != null && dir.isDirectory()) {
            String[] children = dir.list();
            for (int i = 0; i < children.length; i++) {
                boolean success = deleteDir(new File(dir, children[i]));
                if (!success) {
                    return false;
                }
            }
            return dir.delete();
        } else if(dir!= null && dir.isFile()) {
            return dir.delete();
        } else {
            return false;
        }
    }
}

Answer 10

使用 kotlin: 来删除内容：

for (file:File in context?.cacheDir?.listFiles()!!){
             file.delete()
         }

Answer 11

这段代码帮助了我：

// your code
deleteCache(getContext);
//

public void deleteCache(Context context) {
    try {
        File dir = context.getCacheDir();
        if (dir.list() != null) {
            deleteDir2(dir);
        }
    } catch (Exception e) { e.printStackTrace();}
}

public boolean deleteDir2(File dir) {
    if (dir.isDirectory()) {
        for (File child : dir.listFiles()) {
            boolean success = deleteDir2(child);
            if (!success) {
                return false;
            }
        }
    }
    return dir.delete();
}

Answer 12

此代码将删除应用程序的整个缓存，您可以检查应用程序设置并打开应用程序信息并检查缓存大小。使用此代码后，您的缓存大小将为 0KB 。所以它并享受干净的缓存。

 if (Build.VERSION_CODES.KITKAT <= Build.VERSION.SDK_INT) {
            ((ActivityManager) context.getSystemService(ACTIVITY_SERVICE))
                    .clearApplicationUserData();
            return;
        }