如何在片段中从图库中获取图像(jetpack导航组件)

Question

我使用导航组件jetpak，在片段中需要从库中获取图像。我使用这个代码：

ActivityResultLauncher<String> mGetContent = registerForActivityResult(new ActivityResultContracts.GetContent(),
new ActivityResultCallback<Uri>() {
@Override
public void onActivityResult(Uri uri) {
Constants.toast("return!");
imageFile = new File(getRealPathFromURI(uri));
binding.menuFragmentCircularProfileImageview.setImageURI(uri);
}
});

并且在片段附加调用mGetContent 之后

binding.menuFragmentCircularProfileImageview.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
mGetContent.launch("image/*");
//     fromGallery();
}
});

到目前为止一切都很好，美术馆开得很好。但是。。。

但是所选图像不会返回。该应用程序实际上已关闭。我哪里做错了？或者还有其他解决方案吗？

已更新。。。

这是我的片段：

public class MenuFragment extends Fragment implements LogoutDialog.Listener {
private FragmentMenuBinding binding;
private NavController navController = null;
private UserData userData;
private File imageFile;
private final androidx.activity.result.ActivityResultLauncher<String> getContent = registerForActivityResult(new ActivityResultContracts.GetContent(),
new ActivityResultCallback<Uri>() {
@Override
public void onActivityResult(Uri uri) {
Bitmap bitmap = null;
try {
bitmap = MediaStore.Images.Media.getBitmap(requireActivity().getContentResolver(), uri);
} catch (IOException e) {
e.printStackTrace();
}
binding.menuFragmentCircularProfileImageview.setImageBitmap(bitmap);
}
});
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
navController = Navigation.findNavController(requireActivity(), R.id.main_activity_nav_host_fragment);
binding = DataBindingUtil.inflate(inflater , R.layout.fragment_menu, container, false);
return binding.getRoot();
}
@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
assert getArguments() != null;
userData=MenuFragmentArgs.fromBundle(getArguments()).getUserdata();
operation();
}

private void operation(){
binding.menuFragmentCircularProfileImageview.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
getContent.launch("image/*");
}
});
}
}

Answer 1

尝试使用以下代码：

private ActivityResultLauncher startForResultFromGallery = registerForActivityResult(new ActivityResultContracts.StartActivityForResult(), new ActivityResultCallback<ActivityResult>() {
@Override
public void onActivityResult(ActivityResult result) {
if (result.getResultCode() == Activity.RESULT_OK){
try {
if (result.getData() != null){
Uri selectedImageUri = result.getData().getData();
Bitmap bitmap = BitmapFactory.decodeStream(getBaseContext().getContentResolver().openInputStream(selectedImageUri));
// set bitmap to image view here........
binding.menuFragmentCircularProfileImageview.setImageBitmap(bitmap)
}
}catch (Exception exception){
Log.d("TAG",""+exception.getLocalizedMessage());
}
}
}
});

然后在上面的按钮内点击：

Intent intent = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startForResultFromGallery.launch(intent);

Answer 2

您可以在onActivityResult中使用它来获得file

InputStream inputStream = requireActivity().contentResolver().openInputStream(uri)
String fileType = MimeTypeMap.getSingleton().getExtensionFromMimeType(requireContext().contentResolver().getType(uri))
imageFile = File.createTempFile(UUID.randomUUID().toString(), "." + fileType)
inputStream.copyStreamToFile(file)

我从Kotlin移植了这段代码，让我知道是否有语法错误。

Answer 3

我相信你的AndroidManifest.xml中有android:noHistory="true"，请删除它，你应该会收到结果。我相信这个问题与Jetpack导航无关。