Android 文件存储

Android 文件存储

        因 Android1 1谷歌禁止使用requestLegacyExternalStorage ，故将存储方式分为两种方式来进行文件存储。

        存储你的应用打算与其他应用共享的文件，包括媒体、文档和其他文件。在这里咱们将图片保存至图库(共享文件)。

需要存储权限

    private void saveBitmap() {if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {// 检查该权限是否已经获取int i = ContextCompat.checkSelfPermission(FileStorageActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE);// 权限是否已经 授权 GRANTED---授权  DINIED---拒绝if (i != PackageManager.PERMISSION_GRANTED) {// 如果没有授予该权限，就去提示用户请求startRequestPermission();} else {resourceBitmap();}} else {resourceBitmap();}}

保存数据
 

    private void resourceBitmap() {Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.ceshi);boolean isSave = PictureStorageUtils.isSaveImage(this, bitmap, "sccgx");Log.e("File","isSave:"+isSave);}/*** 功能描述：将图片文件保存至本地*/  
public class PictureStorageUtils {public static boolean isSaveImage(Context context, Bitmap bm, String name) {boolean isSave;if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {//大于等于android 10isSave = saveImageQ(context, bm, name);} else {isSave = saveImage(context, bm, name);}return isSave;}private static boolean saveImage(Context context, Bitmap outB, String name) {String imgName = name.isEmpty()?String.valueOf(System.currentTimeMillis()):name;//File.separator就是文件路径String fileName = Environment.getExternalStorageDirectory() + File.separator + "DCIM"+ File.separator + "demo" + File.separator;try {File file = new File(fileName);if (!file.exists()) {file.mkdirs();}Log.e("File","saveAndGetImage:" + file);File filePath = new File(file + "/" + imgName + ".png");Log.e("File","filePath:" + filePath);FileOutputStream out = new FileOutputStream(filePath); //保存到本地，格式为JPEGif (outB.compress(Bitmap.CompressFormat.PNG, 100, out)) {out.flush();out.close();}Log.e("File","saveAndGetImage:END");//刷新图库if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {//高于22版本要手动授权// 检查该权限是否已经获取int i = ContextCompat.checkSelfPermission(context, Manifest.permission.WRITE_EXTERNAL_STORAGE);// 权限是否已经 授权 GRANTED---授权  DINIED---拒绝if (i != PackageManager.PERMISSION_GRANTED) {// 提示用户应该去应用设置界面手动开启权限} else {context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(filePath)));}} else {context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(filePath)));}return true;} catch (FileNotFoundException e) {Log.e("File","FileNotFoundException e.toString: " + e.toString());e.printStackTrace();return false;} catch (IOException e) {Log.e("File","IOException e.toString: " + e.toString());e.printStackTrace();return false;}}//功能描述：Android10及以上保存图片到相册@RequiresApi(api = Build.VERSION_CODES.Q)private static boolean saveImageQ(Context context, Bitmap image, String name) {long mImageTime = System.currentTimeMillis();String mImageFileName = name.isEmpty()?String.valueOf(mImageTime):name;final ContentValues values = new ContentValues();values.put(MediaStore.MediaColumns.RELATIVE_PATH, Environment.DIRECTORY_DCIM+ File.separator + "demo"); //图库(DCIM)中显示的文件夹名。values.put(MediaStore.MediaColumns.DISPLAY_NAME, mImageFileName);values.put(MediaStore.MediaColumns.MIME_TYPE, "image/png");values.put(MediaStore.MediaColumns.DATE_ADDED, mImageTime / 1000);values.put(MediaStore.MediaColumns.DATE_MODIFIED, mImageTime / 1000);values.put(MediaStore.MediaColumns.DATE_EXPIRES, (mImageTime + DateUtils.DAY_IN_MILLIS) / 1000);values.put(MediaStore.MediaColumns.IS_PENDING, 1);Log.e("File",values.get(MediaStore.MediaColumns.RELATIVE_PATH).toString());ContentResolver resolver = context.getContentResolver();final Uri uri = resolver.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);try {//写下我们文件的数据try (OutputStream out = resolver.openOutputStream(uri)) {if (!image.compress(Bitmap.CompressFormat.PNG, 100, out)) {throw new IOException("Failed to compress");}}//一切都很顺利values.clear();values.put(MediaStore.MediaColumns.IS_PENDING, 0);values.putNull(MediaStore.MediaColumns.DATE_EXPIRES);resolver.update(uri, values, null, null);return true;} catch (IOException e) {Log.e("File",e.getMessage());return false;}}
}

测试机：Galaxy A8s

        图片保存路径：Galaxy A8s\Phone\DCIM\demo

测试机：Pixel XL API 31(AS模拟器)

        图片保存路径：/storage/emulated/0/DCIM/demo/sccgx.png