API 13 及以上版本新增 Android 存储权限

Question

我想使用JAVA将图像从ImageView保存到Android中的存储中。我想知道如何授予 API 13 及以上版本的存储权限。

Answer 1

获取所需权限

1. 将这些行添加到 Android Manifest

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_MEDIA_IMAGES" />
<uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE" />

2. 直接在类中的活动中而不是在（onCreate 方法）中

ActivityResultLauncher<String> requestPermission = registerForActivityResult(new ActivityResultContracts.RequestPermission(), isGranted -> {
        if (isGranted) {
            // TODO
        } else {
            // TODO
        }
    });

    ActivityResultLauncher<Intent> android11StoragePermission = registerForActivityResult(new ActivityResultContracts.StartActivityForResult(), result -> {
        if (isPermitted()) {
            // TODO
        } else {
            //TODO
        }
    });

3. 将这两个功能添加到您的活动中

@TargetApi(Build.VERSION_CODES.R)
    private void requestAndroid11StoragePermission() {
        Intent intent = new Intent(Settings.ACTION_MANAGE_APP_ALL_FILES_ACCESS_PERMISSION);
        intent.addCategory("android.intent.category.DEFAULT");
        intent.setData(Uri.parse(String.format("package:%s", getApplicationContext().getPackageName())));
        android11StoragePermission.launch(intent);
    }

    private boolean isPermitted() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
            return Environment.isExternalStorageManager();
        } else {
            return ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED &&
                    ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED;
        }
    }

4. 检查设备API版本并请求权限

if (isPermitted()) {
                //TODO
            } else {
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
                    requestAndroid11StoragePermission();
                } else {
                    requestPermission.launch(Manifest.permission.WRITE_EXTERNAL_STORAGE);
                }
            }

将图像从

ImageView

保存到内部存储器

1. 将此函数添加到您的类中

private void saveImage(Bitmap bitmap) {
        String root = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).toString();
        File myDir = new File(root + "/Cropped Images");

        if (!myDir.exists()) {
            myDir.mkdirs();
        }

        // Generate a unique file name
        String imageName = "Image_" + new Date().getTime() + ".jpg";

        File file = new File(myDir, imageName);
        if (file.exists()) file.delete();

        try {
            // Save the Bitmap to the file
            OutputStream outputStream;
            if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
                outputStream = Files.newOutputStream(file.toPath());
            } else {
                outputStream = new FileOutputStream(file);
            }
            bitmap.compress(Bitmap.CompressFormat.JPEG, 100, outputStream);
            outputStream.flush();
            outputStream.close();

            // Add the image to the MediaStore
            ContentValues values = new ContentValues();
            values.put(MediaStore.Images.Media.DATA, file.getAbsolutePath());
            values.put(MediaStore.Images.Media.MIME_TYPE, "image/jpeg");
            getApplicationContext().getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);

            // Trigger a media scan to update the gallery
            MediaScannerConnection.scanFile(getApplicationContext(), new String[]{file.getAbsolutePath()}, null, null);
        } catch (Exception e) {
            // TODO
        }
    }

2. 将您的 imageview 图像传递给此函数

BitmapDrawable bitmapDrawable = ((BitmapDrawable) imageView.getDrawable());
Bitmap bitmap = bitmapDrawable.getBitmap();
saveImage(bitmap);