Question

我正在构建一个由GridView组成的UI，其中包含从API中提取的图像，我正在使用ImageListAdapter和MovieFragment，当我启动应用程序时，我只是得到一个空屏幕。我已经尝试使用预先下载的图像列表，它的工作原理。从API获取数据是在AsyncTask上，我认为问题是时间问题，即gridview.setAdapter（）过早调用的事实。这是代码：

public static void main(String[] args) {

    HashMap<Integer, HashSet<Integer>> 
    map1 = new HashMap<Integer, HashSet<Integer>>(),
    map2 = new HashMap<Integer, HashSet<Integer>>();
    HashSet<Integer> set1=new HashSet<Integer>();
    set1.add(1);
    set1.add(2);
    map1.put(1,set1);
    map2.put(1,set1);
    System.out.println(map1.values()==map2.values());
    System.out.println(map1.values()+" "+map2.values());
}

公共类MovieFragment扩展Fragment {

public class MainActivity extends AppCompatActivity {

private final String LOG_TAG = MainActivity.class.getSimpleName();


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    if (savedInstanceState == null) {
        getFragmentManager()
                .beginTransaction()
                .add(R.id.container, new MovieFragment())
                .commit();
    }
}}

}

Answer 1

我终于解决了它，我使用了BaseAdapter的扩展而不是ArrayAdapter：

public class ImageAdapter extends BaseAdapter {
    private Context mContext;
    private String[] moviePath;

    public ImageAdapter(Context c, String[] path) {

        mContext = c;
        this.moviePath = path;
    }

    public int getCount() {
        return moviePath.length;
    }

    //Needed due to methods being abstract
    public Object getItem(int position) {return null;}
    public long getItemId(int position) {return 0;}

    // create a new ImageView for each item referenced by the Adapter
    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView imageView = (ImageView) convertView;
        if (imageView == null) {
            // if it's not recycled, initialize some attributes
            imageView = new ImageView(mContext);
            imageView.setLayoutParams(new GridView.LayoutParams(500, 500));
            imageView.setPadding(5, 5, 5, 5);
        } else {
            imageView = (ImageView) convertView;
        }

        //imageView.setImageResource(mThumbIds[position]);
        Picasso.with(getActivity())
                .load(moviePath[position])
                .fit()
                .into(imageView);
        return imageView;
    }
}

我还在onPostExecute（）方法中使用了setAdapter（）。

谢谢大家的帮助= D

GridView适配器没有填充？不按时填充？没有在onPostExecute（）中更新？

1 个答案: