Question

我对OnItemClickListener有困难。当我还有一个OnScrollListener时，不会调用onItemClick。我将问题缩小到：

public void onScroll(AbsListView absListView, int firstVisible, int visibleCount, int totalCount)

如果在此过程中我调用adapter.notifyDataSetChanged（），则OnItemClickListener不起作用。任何人有什么建议，或如何解决这个问题？我在onScroll和onScrollStateChanged都有断点，但似乎没有触及它们。

public class ArticleListActivity extends Activity implements AdapterView.OnItemClickListener, AbsListView.OnScrollListener {

    private long categoryId = 0;
    private List<Article> objects;
    private ArticleListAdapter adapter;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.article_list);

        Bundle extras = getIntent().getExtras();
        if(extras != null){
            if(extras.containsKey("categoryId")) categoryId = extras.getLong("categoryId");
        }

        ListView lv = (ListView) findViewById(R.id.article_list_activity);
        iDomsAndroidApp app = ((iDomsAndroidApp) getApplicationContext());

        try {
            objects = app.getDataManager().getArticlesForCategory(categoryId, 15);
            adapter = new ArticleListAdapter(this, R.layout.article_list_cell, objects, categoryId);
            lv.setOnScrollListener(this);
            lv.setOnItemClickListener(this);
            lv.setAdapter(adapter);
        } catch (Exception e){
            Log.e(iDomsAndroidApp.TAG, "Error " + e.getMessage(), e);
        }


    }

    public void onItemClick(AdapterView<?> parent, View view,
                            int position, long id) {
        // When clicked, show a toast with the TextView text
        Toast.makeText(getApplicationContext(), objects.get(position).getTitle(),
                Toast.LENGTH_SHORT).show();


        Intent intent = new Intent(view.getContext(), ArticleActivity.class);
        intent.putExtra("articleId", objects.get(position).getId());
        startActivity(intent);


    }

    public void onScrollStateChanged(AbsListView absListView, int i) {

    }

    public void onScroll(AbsListView absListView, int firstVisible, int visibleCount, int totalCount) {   
        if(totalCount == 0) return;

        // For the moment only add, not remove items out of view. Buffer of 5.
        int buffer = 5;

        if(adapter.getCount() + buffer < firstVisible + visibleCount){
            Log.d(iDomsAndroidApp.TAG, adapter.getCount() + " + " + buffer + " < " + firstVisible + visibleCount);
            // Get next set
            try {
                iDomsAndroidApp app = ((iDomsAndroidApp) adapter.getContext().getApplicationContext());
                List<Article> newObjects = app.getDataManager().getArticlesForCategory(categoryId, adapter.getCount(), totalCount + buffer - adapter.getCount());
                for(Article item : newObjects){
                    adapter.add(item);
                }
            } catch (Exception e){
                Log.e(iDomsAndroidApp.TAG, "Error " + e.getMessage(), e);
            }
        }

        adapter.notifyDataSetChanged();
    }

}

Answer 1

我不知道原因，但是我通过将adapter.notifyDataSetChanged（）移动到更新循环（以及其他一些性能增强）来解决了这个问题。性能方面，无论如何这都是有意义的，否则它将被视图的每次移动调用，这是不必要的。这解决了这个问题。

OnItemClickListener在ListView上不工作icm OnScrollListener

1 个答案: