在我的应用程序中显示来自设备的所有图像

Question

我正在使用下面的代码从 DCIM 内的 Camera 文件夹中获取所有图像并显示在我的应用程序中。但我想在我的应用程序中显示设备上的所有图像，无论它们存储在设备上的什么位置。我该怎么做？

 String ExternalStorageDirectoryPath = Environment
                .getExternalStorageDirectory()
                .getAbsolutePath();
        String targetPath = ExternalStorageDirectoryPath + "/DCIM/Camera";
        images=new ArrayList<String>();
        File targetDirector = new File(targetPath);

        File[] files = targetDirector.listFiles();
        for (File file : files) {

            images.add(file.getAbsolutePath());
        }
        gallerylist=new CameraGalleryAdapter(getActivity().getApplicationContext(),R.layout.giphy_grid,images);
        gridview.setAdapter(gallerylist);

Answer 1

首先检查是否授予了所需的权限：

if (ActivityCompat.checkSelfPermission(CurrentActivity.this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
     ActivityCompat.requestPermissions(CurrentActivity.this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE}, PICK_FROM_GALLERY)
}

然后你必须检查SD卡是否可用：

Boolean isSDPresent = android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);

如果存在 SD 卡，则使用此卡：

final String[] columns = { MediaStore.Images.Media.DATA, MediaStore.Images.Media._ID };
final String orderBy = MediaStore.Images.Media._ID;
//Stores all the images from the gallery in Cursor
Cursor cursor = getContentResolver().query(
        MediaStore.Images.Media.EXTERNAL_CONTENT_URI, columns, null,
        null, orderBy);
//Total number of images
int count = cursor.getCount();

//Create an array to store path to all the images
String[] arrPath = new String[count];

for (int i = 0; i < count; i++) {
    cursor.moveToPosition(i);
    int dataColumnIndex = cursor.getColumnIndex(MediaStore.Images.Media.DATA);
    //Store the path of the image
    arrPath[i]= cursor.getString(dataColumnIndex);
    Log.i("PATH", arrPath[i]);
}
// The cursor should be freed up after use with close()
cursor.close();

上面的代码将列出所有来自 SD 卡的图像，如果要从内存中获取图像，只需替换

MediaStore.Images.Media.EXTERNAL_CONTENT_URI

与

MediaStore.Images.Media.INTERNAL_CONTENT_URI

使用相同的 sn-p 代码。