java - 我的 ListView 不起作用。我在这里错过了一些东西

Question

我转换了这一行:lv1.setOnItemClickListener((OnItemClickListener) this);因为它会创建一条红色的波浪线。我是否正确使用了 onItemClick 函数？

 public class MainActivity extends Activity {

private ListView lv1;
private String lv_arr[] = {
        "Android",
        "iPhone",
        "Blackberry",
        "AndroidPeople"
};


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    lv1 = (ListView) findViewById(R.id.ListView01);
    lv1.setOnItemClickListener((OnItemClickListener) this);
    //by using setAdapter method in ListView, we can add string array in list

    lv1.setAdapter(new ArrayAdapter<String>(
            this, android.R.layout.simple_list_item_1, lv_arr));

}

public void onItemClick(AdapterView arg0, View v, int position, long arg3){

    Toast.makeText(this, "You clicked" + lv_arr[position],       Toast.LENGTH_LONG).show();

}



 }

Answer 1

您的MainActivity没有实现OnItemClickListener ，这就是为什么它给你“红色波浪线”。

您应该将类​​声明更改为:

public class MainActivity extends Activity implements OnItemClickListener {

这意味着您不必转换 MainActivity到OnItemClickListener将其设置为您的 ListView 时