Question

所以我在gridview中放置了一个图像，它在开始时工作正常，并显示20个图像，但是当我试图显示少于它时，它不会更新。当gridview更新时有一个条件，当我加载20个图像时它会更新，但是当我尝试加载更少或零时它不会更新。

我该如何解决这个问题？

这是我在适配器上的代码

 private final Context context;
private List<Movie> urls = new ArrayList<>();

public MovieGridViewAdapter(Context context, List<Movie> urls) {
    this.context = context;
    this.urls = urls;
}

@Override
public int getCount() {
    if (urls.size() == 0){
        return 0;
    }
    return urls.size();
}

@Override
public Movie getItem(int position) {
    return urls.get(position);
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(int position, View view, ViewGroup viewGroup) {
    View gridView = view;
    if (gridView == null) {
        gridView = LayoutInflater.from(context)
                .inflate(R.layout.item_poster, viewGroup, false);
    }
    ImageView posterImageView = (ImageView) gridView.findViewById(R.id.posterImageView);

    // Get the image URL for the current position.
    Movie movie = getItem(position);

    //needed to append the image url
    String imageBaseUrl = "http://image.tmdb.org/t/p/w185";

    Picasso.with(context) //
            .load(imageBaseUrl+movie.getPosterPath()) //
            .placeholder(R.drawable.ic_hourglass_empty_black_24dp) //
            .error(R.drawable.ic_error_black_24dp) //
            .fit() //
            .tag(context) //
            .into(posterImageView);

    Log.v("jalan ji", "jalan");
    return gridView;
}

这是我尝试更新Gridview的地方

List<Favorite> favorites = new ArrayList<>();
    Cursor cursor = getContentResolver().query(MovieContract.MovieEntry.CONTENT_URI,
            null,
            null,
            null,
            MovieContract.MovieEntry.COLUMN_TITLE);
    while(cursor.moveToNext()){
        String id = cursor.getString(cursor.getColumnIndex(MovieContract.MovieEntry.COLUMN_MOVIE_ID));
        String title = cursor.getString(cursor.getColumnIndex(MovieContract.MovieEntry.COLUMN_TITLE));

        try{
            Favorite fav = new Favorite();
            fav.setId(id);
            fav.setTitle(title);
            favorites.add(fav);
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    for(Favorite favorite : favorites){
        Call<MovieSingle> call = movieDbClient.getMovie(favorite.getId(), apiKey);
        setTitle("Favorite Movies");

        call.enqueue(new Callback<MovieSingle>() {
            @Override
            public void onResponse(@NonNull Call<MovieSingle> call, @NonNull Response<MovieSingle> response) {
                Movie mov = new Movie();
                mov.setBackdropPath(response.body().getBackdrop_path());
                mov.setOverview(response.body().getOverview());
                mov.setReleaseDate(response.body().getRelease_date());
                mov.setTitle(response.body().getTitle());
                mov.setVoteAverage(response.body().getVote_average());
                mov.setPosterPath(response.body().getPoster_path());
                movie.add(mov);
                Log.v("berhasil", " "+response.body().getTitle());
            }

            @Override
            public void onFailure(@NonNull Call<MovieSingle> call, @NonNull Throwable t) {
                t.printStackTrace();
                pbar.setVisibility(View.INVISIBLE);
                Log.v("gagal", "berhasil");
                showErrorMessage();
            }
        });
    }

    showGridView();
    pbar.setVisibility(View.INVISIBLE);

    MovieGridViewAdapter movieGridViewAdapter = new MovieGridViewAdapter(getApplicationContext(), movie);
    Log.v("Test", movie.get(2).getTitle());
    Log.v("Test", movie.get(2).getPosterPath());
    movieGridViewAdapter.notifyDataSetChanged();
    gridView.invalidateViews();
    gridView.setAdapter(movieGridViewAdapter);

和布局

<FrameLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/bgdetail">

    <GridView android:id="@+id/movieitem_grid"
              android:layout_marginTop="50dp"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:columnWidth="165dp"

              android:scrollbarStyle="insideOverlay"
              android:scrollbars="none"
              android:listSelector="@null"
              android:numColumns="auto_fit"/>
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/tv_error"
        android:layout_gravity="center"
        android:textAlignment="center"
        android:textColor="@color/textColor"
        android:text="@string/error_msg"
        android:visibility="invisible"
        android:textSize="22sp"/>
    <ProgressBar
        android:layout_width="68dp"
        android:layout_height="68dp"
        android:layout_gravity="center"
        android:id="@+id/progressbar"
        android:visibility="invisible"/>

</FrameLayout>

Answer 1

解决了，我必须将setAdapter方法放在循环中并创建list的新变量并使其成为final，不能使用全局变量。所以最终的代码看起来应该是这样的

List<Favorite> favorites = new ArrayList<>();
    final List<Movie> movie1 = new ArrayList<>();
    Cursor cursor = getContentResolver().query(MovieContract.MovieEntry.CONTENT_URI,
            null,
            null,
            null,
            MovieContract.MovieEntry.COLUMN_TITLE);
    while(cursor.moveToNext()){
        String id = cursor.getString(cursor.getColumnIndex(MovieContract.MovieEntry.COLUMN_MOVIE_ID));
        String title = cursor.getString(cursor.getColumnIndex(MovieContract.MovieEntry.COLUMN_TITLE));

        try{
            Favorite fav = new Favorite();
            fav.setId(id);
            fav.setTitle(title);
            favorites.add(fav);
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    for(Favorite favorite : favorites){
        Call<MovieSingle> call = movieDbClient.getMovie(favorite.getId(), apiKey);
        setTitle("Favorite Movies");

        call.enqueue(new Callback<MovieSingle>() {
            @Override
            public void onResponse(@NonNull Call<MovieSingle> call, @NonNull Response<MovieSingle> response) {
                Movie mov = new Movie();
                mov.setBackdropPath(response.body().getBackdrop_path());
                mov.setOverview(response.body().getOverview());
                mov.setReleaseDate(response.body().getRelease_date());
                mov.setTitle(response.body().getTitle());
                mov.setVoteAverage(response.body().getVote_average());
                mov.setPosterPath(response.body().getPoster_path());
                movie1.add(mov);
                showGridView();
                pbar.setVisibility(View.INVISIBLE);
                MovieGridViewAdapter movieGridViewAdapter = new MovieGridViewAdapter(getApplicationContext(), movie1);
                movieGridViewAdapter.notifyDataSetChanged();
                gridView.setAdapter(movieGridViewAdapter);
                Log.v("berhasil", " "+movie1.get(0).getTitle());
            }

            @Override
            public void onFailure(@NonNull Call<MovieSingle> call, @NonNull Throwable t) {
                t.printStackTrace();
                pbar.setVisibility(View.INVISIBLE);
                Log.v("gagal", "berhasil");
                showErrorMessage();
            }
        });
    }

Gridview无法更新Android

1 个答案: