StorageClient

路径

...\sdk\samples\android-23\content\StorageClient

描述

Storage Access Framework（SAF），Android 4.4 (API level 19) 后引入的一个功能，可以打开一个类似文件选择器的界面，通过setType()来设置需要选择什么类型的文件。此次示例打开的是图片选择器

知识点

/**     * Fires an intent to spin up the "file chooser" UI and select an image.     */    public void performFileSearch() {        // BEGIN_INCLUDE (use_open_document_intent)        // ACTION_OPEN_DOCUMENT is the intent to choose a file via the system's file browser.        Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);        // Filter to only show results that can be "opened", such as a file (as opposed to a list        // of contacts or timezones)        intent.addCategory(Intent.CATEGORY_OPENABLE);        // Filter to show only images, using the image MIME data type.        // If one wanted to search for ogg vorbis files, the type would be "audio/ogg".        // To search for all documents available via installed storage providers, it would be        // "*/*".        intent.setType("image/*");        startActivityForResult(intent, READ_REQUEST_CODE);        // END_INCLUDE (use_open_document_intent)    }

通过Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
创建一个Intent，再添加intent.addCategory(Intent.CATEGORY_OPENABLE);，最后设置打开类型intent.setType("image/*");
如果要过滤文本可以设置
intent.setType("text/*");
不过滤

intent.setType("*/*");

使用startActivityForResult(intent, READ_REQUEST_CODE);来启动。

在onActivityResult中接收返回的结果

@Override    public void onActivityResult(int requestCode, int resultCode, Intent resultData) {        Log.i(TAG, "Received an \"Activity Result\"");        // BEGIN_INCLUDE (parse_open_document_response)        // The ACTION_OPEN_DOCUMENT intent was sent with the request code READ_REQUEST_CODE.        // If the request code seen here doesn't match, it's the response to some other intent,        // and the below code shouldn't run at all.        if (requestCode == READ_REQUEST_CODE && resultCode == Activity.RESULT_OK) {            // The document selected by the user won't be returned in the intent.            // Instead, a URI to that document will be contained in the return intent            // provided to this method as a parameter.  Pull that uri using "resultData.getData()"            Uri uri = null;            if (resultData != null) {                uri = resultData.getData();                Log.i(TAG, "Uri: " + uri.toString());                showImage(uri);            }            // END_INCLUDE (parse_open_document_response)        }    }

如果返回结果不为空，展示这张图片

if (resultData != null) {                uri = resultData.getData();                Log.i(TAG, "Uri: " + uri.toString());                showImage(uri);}/**     * Given the URI of an image, shows it on the screen using a DialogFragment.     *     * @param uri the Uri of the image to display.     */    public void showImage(Uri uri) {        // BEGIN_INCLUDE (create_show_image_dialog)        if (uri != null) {            // Since the URI is to an image, create and show a DialogFragment to display the            // image to the user.            FragmentManager fm = getActivity().getSupportFragmentManager();            ImageDialogFragment imageDialog = new ImageDialogFragment();            Bundle fragmentArguments = new Bundle();            fragmentArguments.putParcelable("URI", uri);            imageDialog.setArguments(fragmentArguments);            imageDialog.show(fm, "image_dialog");        }        // END_INCLUDE (create_show_image_dialog)    }

这里使用了DialogFragment。