来自android内部存储的file.delete()返回false

Question

我有一种方法从url下载图像并将其保存在内部存储的文件夹中

 public void saveDynamicImage(String url,String fileName, String folderName) {

    InputStream iStream;

    BufferedInputStream buffInputStream;
    ByteArrayBuffer byteArray = null;

    try {
        HttpGet httpGet = new HttpGet(url);
        HttpClient httpClient = new DefaultHttpClient();
        HttpResponse httpResponse = httpClient.execute(httpGet);
        iStream = httpResponse.getEntity().getContent();

        buffInputStream = new BufferedInputStream(iStream, 8 * 1024);
        byteArray = new ByteArrayBuffer(50);
        int current = 0;
        while ((current = buffInputStream.read()) != -1) {
            byteArray.append((byte) current);
        } 

    } catch (ClientProtocolException e1) {
    } catch (IOException e1) {
    }

    File dynamicImageDir = context.getDir(AppConstants.DYNAMIC_IMAGE, Context.MODE_PRIVATE);
    File appNamefileDir = new File(dynamicImageDir, BaseActivity.appDataStore.getAppName());
    appNamefileDir.mkdirs();
    File controlNameDir = new File(appNamefileDir, folderName);
    controlNameDir.mkdirs();
    File file = new File(controlNameDir, fileName);

    try {
        FileOutputStream outputStream = new FileOutputStream(file);
        outputStream.write(byteArray.toByteArray());
        outputStream.close();
        System.out.println("DynamicImage saving over!..");
    } catch (FileNotFoundException e) {
    } catch (IOException e) {
    }
}

我想在一个时间点删除整个目录.我删除整个目录的方法是

public void deleteDynamicImage() throws NullPointerException,FileNotFoundException {
    File rootDirectory = context.getDir(AppConstants.DYNAMIC_IMAGE, Context.MODE_WORLD_WRITEABLE);
    boolean status = rootDirectory.delete();
    Log.e("", "delete : "+status);

}

我的状态为"假".文件已创建且工作正常.只有删除的问题.有什么我想念的吗？

Answer 1

你的文件是目录吗？

如果是,则需要先删除此文件夹中的文件,
此代码才能正常工作

public void deleteDirectory(File file) {
    if( file.exists() ) {
        if (file.isDirectory()) {
            File[] files = file.listFiles();
            for(int i=0; i<files.length; i++) {
                if(files[i].isDirectory()) {
                    deleteDirectory(files[i]);
                }
                else {
                    files[i].delete();
                }
            }
        }
            file.delete();
    }
}

Answer 2

删除目录使用此:

public void DeleteRecursive(File fileOrDirectory) {
    if (fileOrDirectory.isDirectory()) for (File child : fileOrDirectory.listFiles())
    DeleteRecursive(child);
    fileOrDirectory.delete();
}