从firebase检索碎片中回收者视图的图像时出错

Question

我想在片段

中检索回收者视图的图像MovieActivity代码:

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
Intent intent = new Intent(this, LoadingActivity.class);
startActivity(intent);
setupViewFragment();
}
setupToolbar();
setupBottomNavigation();
}
private void setupViewFragment() {
// show discover movies fragment by default
DiscoverMoviesFragment discoverMoviesFragment = DiscoverMoviesFragment.newInstance();
ActivityUtils.replaceFragmentInActivity(
getSupportFragmentManager(), discoverMoviesFragment, R.id.fragment_container);
}
private void setupBottomNavigation() {
BottomNavigationView bottomNav = findViewById(R.id.bottom_navigation);
bottomNav.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
switch (menuItem.getItemId()) {
case R.id.action_home:
ActivityUtils.replaceFragmentInActivity(
getSupportFragmentManager(), HomeFragment.newInstance(),
R.id.fragment_container);
//startActivity(new Intent(getApplicationContext()
//,HomeActivity.class));
return true;
case R.id.action_discover:
ActivityUtils.replaceFragmentInActivity(
getSupportFragmentManager(), DiscoverMoviesFragment.newInstance(),
R.id.fragment_container);
return true;
case R.id.action_favorites:
ActivityUtils.replaceFragmentInActivity(
getSupportFragmentManager(), FavoritesFragment.newInstance(),
R.id.fragment_container);
return true;
}
return false;
}
});
}
private void setupToolbar() {
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
}

}'

HomeFragment代码:

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
Intent intent = new Intent(this, LoadingActivity.class);
startActivity(intent);
setupViewFragment();
}
setupToolbar();
setupBottomNavigation();
}
private void setupViewFragment() {
// show discover movies fragment by default
DiscoverMoviesFragment discoverMoviesFragment = DiscoverMoviesFragment.newInstance();
ActivityUtils.replaceFragmentInActivity(
getSupportFragmentManager(), discoverMoviesFragment, R.id.fragment_container);
}
private void setupBottomNavigation() {
BottomNavigationView bottomNav = findViewById(R.id.bottom_navigation);
bottomNav.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
switch (menuItem.getItemId()) {
case R.id.action_home:
ActivityUtils.replaceFragmentInActivity(
getSupportFragmentManager(), HomeFragment.newInstance(),
R.id.fragment_container);
//startActivity(new Intent(getApplicationContext()
//,HomeActivity.class));
return true;
case R.id.action_discover:
ActivityUtils.replaceFragmentInActivity(
getSupportFragmentManager(), DiscoverMoviesFragment.newInstance(),
R.id.fragment_container);
return true;
case R.id.action_favorites:
ActivityUtils.replaceFragmentInActivity(
getSupportFragmentManager(), FavoritesFragment.newInstance(),
R.id.fragment_container);
return true;
}
return false;
}
});
}
private void setupToolbar() {
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
}

}

HomeAdapter代码:

public class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.ImageViewHolder> {
private Context mContext;
private List<Upload> mUploads;
private OnItemClickListener mListener;
public HomeAdapter(Context context, List<Upload> uploads) {
mContext = context;
mUploads = uploads;
}
@Override
public ImageViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(mContext).inflate(R.layout.image_item, parent, false);
return new ImageViewHolder(v);
}
@Override
public void onBindViewHolder(ImageViewHolder holder, int position) {
Upload uploadCurrent = mUploads.get(position);
holder.textViewName.setText(uploadCurrent.getName());
Picasso.get()
.load(uploadCurrent.getImageUrl())
.placeholder(R.mipmap.ic_launcher)
.centerInside()
.fit()
.into(holder.imageView);
}
@Override
public int getItemCount() {
return mUploads.size();
}
public class ImageViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener,
View.OnCreateContextMenuListener, MenuItem.OnMenuItemClickListener {
public TextView textViewName;
public ImageView imageView;
public ImageViewHolder(View itemView) {
super(itemView);
textViewName = itemView.findViewById(R.id.text_view_name);
imageView = itemView.findViewById(R.id.image_view_upload);
itemView.setOnClickListener(this);
itemView.setOnCreateContextMenuListener(this);
}
@Override
public void onClick(View v) {
if (mListener != null) {
int position = getAdapterPosition();
if (position != RecyclerView.NO_POSITION) {
mListener.onItemClick(position);
}
}
}
@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
menu.setHeaderTitle("Select Action");
MenuItem doWhatever = menu.add(Menu.NONE, 1, 1, "Do whatever");
MenuItem delete = menu.add(Menu.NONE, 2, 2, "Delete");
doWhatever.setOnMenuItemClickListener(this);
delete.setOnMenuItemClickListener(this);
}
@Override
public boolean onMenuItemClick(MenuItem item) {
if (mListener != null) {
int position = getAdapterPosition();
if (position != RecyclerView.NO_POSITION) {
switch (item.getItemId()) {
case 1:
mListener.onWhatEverClick(position);
return true;
case 2:
mListener.onDeleteClick(position);
return true;
}
}
}
return false;
}
}
public interface OnItemClickListener {
void onItemClick(int position);
void onWhatEverClick(int position);
void onDeleteClick(int position);
}
public void setOnItemClickListener(OnItemClickListener listener) {
mListener = listener;
}

}

这是错误:

' C:UsersUserDesktopPopularMoviesappsrcmainjavacomajdiyassin PopularMovies uimovieslisthomeHomeFragment.java:65:错误:不兼容的类型:HomeFragment无法转换为Context

mAdapter = new HomeAdapter(HomeFragment.this, mUploads);`

Answer 1

使用getApplicationContext(),因为HomeFragment.this在你的HomeAdapter构造函数中，你传递了Context.

替换:

mAdapter = new HomeAdapter(HomeFragment.this, mUploads);

:

mAdapter = new HomeAdapter(getApplicationContext(), mUploads);