Android5.0以上SDCard文件删除问题

最近接触到一个功能，要删除SDCard的文件。结果失败了。

下面是正确的方法：

1. 向用户申请权限。调用下面的代码，会弹出一个文件预览Activity， 选择SDCard的文件目录。所以在UI上一定要先提示用户选择SDCard根目录。

final Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE);
startActivityForResult(intent, SDCARD_PERMISSION_REQUEST);

    private void checkSDCardPermission() {
        if (!DeviceStorageUtil.hasSDCard()) {
            return;
        }

        CustomDialog dialog = new CustomDialog.Builder()
                .setContext(this)
                .setTitle(getString(R.string.cleanup_clean_sdcard_garbage))
                .setMessage(getString(R.string.cleanup_clean_sdcard_permission_hint))
                .setPositive(getString(R.string.cleanup_select_sd_card), new CustomDialog.onContinueClickListener() {
                    @Override
                    public void onContinueClick() {
                        final Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE);
                        startActivityForResult(intent, SDCARD_PERMISSION_REQUEST);
                    }
                })
                .build();
        dialog.show();
    }

2. 保存SDCard目录对应的URI，并且打开权限。

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == SDCARD_PERMISSION_REQUEST && resultCode == RESULT_OK) {
            Uri url = data.getData();
            if (url != null) {
                getContentResolver().takePersistableUriPermission(url, Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
                DeviceStorageUtil.setSDCardPermissionUri(url);
            }
        }
    }

 

3. 删除文件。

SDCARD_PERMISSION_URI就是上面一步取得的URI, SDCARD_UUID 就是SDCARD的识别码，类似于：“123-456：”

    public static boolean deleteSDCardFile(File file) {
        if (file != null) {

            try {
                Uri uri = DocumentsContract.buildDocumentUriUsingTree(SDCARD_PERMISSION_URI, SDCARD_UUID + file.getPath().replace(getSDCardRoot(), ""));
                return DocumentsContract.deleteDocument(BaseApplication.getInstance().getApplicationContext().getContentResolver(), uri);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
                return false;
            }
        }

        return false;
    }

    public static String getSDCardRoot() {
        if (!TextUtils.isEmpty(SDCARD_ROOT_FOLDER))
            return SDCARD_ROOT_FOLDER;

        String[] paths = null;
        try {
            StorageManager sm = (StorageManager) BaseApplication.getInstance().getApplicationContext().getSystemService(Context.STORAGE_SERVICE);
            paths = (String[]) sm.getClass().getMethod("getVolumePaths").invoke(sm);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        if (paths != null) {
            String external = Environment.getExternalStorageDirectory().getAbsolutePath();
            for (String path : paths) {
                if (!TextUtils.equals(path, external)) {
                    SDCARD_ROOT_FOLDER = path;
                    return path;
                }
            }
        }

        SDCARD_ROOT_FOLDER = null;
        return null;
    }

 

本文地址：https://blog.csdn.net/zjuter/article/details/112611293