java - Android 自定义 ListView 适配器在数据被删除时行为异常

Question

基本上，这是 MainActivity 类的相关代码块:

private ListView listView;
private ArrayList<String> tasks = new ArrayList<String>();

private CustomListViewAdapter customListViewAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    tasks.add("Hfrfello");
    tasks.add("Heefrefllo");
    tasks.add("Hellefrefo");
    tasks.add("Helggglo");
    tasks.add("Helggglo");
    tasks.add("aaHello");
    tasks.add("aaaaaaHelaaalo");
    tasks.add("Hfrfello");
    tasks.add("Heefrefllo");
    tasks.add("Hellefrefo");
    tasks.add("Helggglo");
    tasks.add("Helggglo");
    tasks.add("aaHello");
    tasks.add("aaaaaaHelaaalo");

    this.listView = (ListView) findViewById(R.id.tasks);

    this.customListViewAdapter = new CustomListViewAdapter(getApplicationContext(), this.tasks);

    this.listView.setAdapter(this.customListViewAdapter);

    this.listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            //deleteTask(position);

            customListViewAdapter.remove(position);
            //tasks.remove(position);
            customListViewAdapter.notifyDataSetChanged();
        }
    });
}

这是我的 CustomListViewAdapter 类:

package com.hassanalthaf.dailytaskmanager;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.ArrayList;

public class CustomListViewAdapter extends BaseAdapter {
    private Context context;
    private ArrayList<String> tasks;
    private static LayoutInflater inflater = null;

    public CustomListViewAdapter(Context context, ArrayList<String> data) {
        this.context = context;
        this.tasks = data;
        this.inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    @Override
    public int getCount() {
        return this.tasks.size();
    }

    @Override
    public Object getItem(int position) {
        return position;
    }

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

    public void remove(int position) {
        this.tasks.remove(position);
        System.out.println(this.tasks);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View view = convertView;

        if (convertView == null) {
            view = this.inflater.inflate(R.layout.list_row, null);

            TextView taskName = (TextView) view.findViewById(R.id.taskName);
            ImageView image = (ImageView) view.findViewById(R.id.deleteButton);

            String task = this.tasks.get(position);

            taskName.setText(task);
        }

        return view;
    }
}

我的问题:当我单击图形用户界面时，它确实删除并更新了 ListView，但是更新错误。它的作用是，当我单击前 3 个元素(应该删除它们)时，它会从 ArrayList 中删除它们，并且在删除它们后我会得到正确的输出。但是，在用户界面中，它并没有删除我单击的内容，而是仅删除底部的项目，而不触及顶部的项目。我该如何解决这个问题？

Answer 1

您的 getView() 未设置回收的 convertView 对象的状态，因此它们继续显示旧状态。试试这个:

@Override 
public View getView(int position, View convertView, ViewGroup parent) {
    View view = convertView;

    if (convertView == null) {
        view = this.inflater.inflate(R.layout.list_row, null);
    }

    TextView taskName = (TextView) view.findViewById(R.id.taskName);
    String task = this.tasks.get(position);
    taskName.setText(task);

    return view;
}