Question

我正在尝试将数据从SQLite数据库填充到列表视图，但我的列表视图没有显示任何内容。当我将项目 list_collections 填充数据时这是我的示例代码。

public class Collection_List_Activity extends ActionBarActivity {
private DB_Nabege_helper nabege_db = new DB_Nabege_helper(this);
private ListView list_collections;
private Button btn_Go_to_add_collection;
private int[] id_tbl_collection;
private String[] name_collection_tbl_collection;
private EditText word_search_collection;
private Cursor cur_collection;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_collection__list_);
    // =================================================================

    list_collections = (ListView) findViewById(R.id.listView_collections);
    TextView textViwempty = (TextView) findViewById(R.id.textview_no_subject);
    list_collections.setEmptyView(textViwempty); 
    // =================================================================
    go_to_add_collection();
    fill_listView("");
    word_search_collection = (EditText) findViewById(R.id.txt_search_collection);

    list_collections.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
            Intent goTo_SubjectsActivity = new Intent(Collection_List_Activity.this, Subjects_Activity.class);
            goTo_SubjectsActivity.putExtra("id_collection", id_tbl_collection[arg2]);
            startActivity(goTo_SubjectsActivity);
        }
    });

    word_search_collection.addTextChangedListener(new TextWatcher() {

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            if (s.length() > 2) {
                fill_listView(word_search_collection.toString());
            }
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                    }

        @Override
        public void afterTextChanged(Editable s) {

        }
    });
}


private void go_to_add_collection() {
    btn_Go_to_add_collection = (Button) findViewById(R.id.btn_new_collection);
    btn_Go_to_add_collection.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View arg0) {
            Intent goToHelpActivity = new Intent(Collection_List_Activity.this, AddCollectionActivity.class);
            startActivity(goToHelpActivity);
        }
    });
}


private void fill_listView(String word) {
    int count_tbl_collection = nabege_db.count_collection(word);
    id_tbl_collection = new int[count_tbl_collection];
    name_collection_tbl_collection = new String[count_tbl_collection];
    nabege_db.open();
    cur_collection = nabege_db.display_collection(word);
    try {
        if (cur_collection != null)
            for (int i = 0; i < count_tbl_collection; i++) {
                cur_collection.moveToPosition(i);
                id_tbl_collection[i] = cur_collection.getInt(0);
                name_collection_tbl_collection[i] = cur_collection.getString(1);
            }
    } catch (Exception e) {
        Toast.makeText(getApplicationContext(), e.toString(), Toast.LENGTH_LONG).show();
        Log.d("mylog", e.toString());
    }
    list_collections.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, name_collection_tbl_collection));
    nabege_db.close();
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.collection__list_, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

@Override
protected void onResume() {
    super.onResume();
    fill_listView(word_search_collection.toString());
}

// end class

}

我再次尝试通过新数组填充数据。我改变了这一行

list_collections.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, name_collection_tbl_collection));

像这样：

list_collections.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,new String[]{"5","4","3","2","1"}));

列表视图显示所有数据。我不明白问题，因为logcat没有错误。请给我提示或建议。

Answer 1

更改

fill_listView(word_search_collection.toString());

到

fill_listView(word_search_collection.getText().toString());

这会将正确的字符串分配给word变量，您的程序将正常工作感谢

为什么列表视图不显示Android应用程序中的数据数组？

1 个答案: