Android新手开发之旅-ListView动态添加删除数据

liu

ListView动态添加删除数据




实现方法就是通过控制数据的增加或者删除，然后刷新适配器即可





举例

activity_main.xml:

[XML] 纯文本查看 复制代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <ListView
        android:id="@+id/lv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <Button
        android:id="@+id/btn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="20dp"
        android:text="添加数据" />
</LinearLayout>

item_listview.xml:

[XML] 纯文本查看 复制代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/tv"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_marginLeft="15dp"
            android:layout_weight="1"
            android:gravity="center_vertical"
            android:textColor="@android:color/black" />

        <Button
            android:id="@+id/btn"
            android:layout_width="wrap_content"
            android:layout_height="40dp"
            android:layout_marginRight="15dp"
            android:background="@color/colorAccent"
            android:text="删除"
            android:textColor="@android:color/white" />
    </LinearLayout>
</LinearLayout>

MyAdapter:

[Java] 纯文本查看 复制代码

package com.company.helloworld.firstapplication;

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

import java.util.List;

/**
 * Created by Administrator on 2018/12/13.
 */

public class MyAdapter extends BaseAdapter {
    private Context context;
    private List<String> list;

    public MyAdapter(Context context, List<String> list) {
        this.context = context;
        this.list = list;
    }

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

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

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

    @Override
    public View getView(final int position, View convertView, ViewGroup viewGroup) {
        ViewHolder holder;
        if (convertView == null) {
            holder = new ViewHolder();
            convertView = LayoutInflater.from(context).inflate(R.layout.item_listview, null);
            holder.tv = convertView.findViewById(R.id.tv);
            holder.btn = convertView.findViewById(R.id.btn);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }
        holder.tv.setText(list.get(position));
        holder.btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //从数据源中把所点击的数据移除
                list.remove(list.get(position));
                //刷新适配器
                MyAdapter.this.notifyDataSetChanged();
            }
        });
        return convertView;
    }

    //用于缓存控件
    public class ViewHolder {
        private TextView tv;
        private Button btn;
    }
}

MainActivity:

[Java] 纯文本查看 复制代码

package com.company.helloworld.firstapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ListView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private Button mButton;
    private ListView mListView;
    private List<String> list;

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

        initData();
        initView();
    }

    private void initData() {
        list = new ArrayList<>();
        for (int i = 1; i < 11; i++) {
            list.add("第" + i + "条数据");
        }
    }

    private void initView() {
        mButton = (Button) findViewById(R.id.btn);
        mListView = (ListView) findViewById(R.id.lv);
        final MyAdapter adapter = new MyAdapter(this, list);
        mListView.setAdapter(adapter);

        mButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //向数据源中添加数据    第一个参数代表添加的位置   想要把数据添加到最后一个位置时可以写成 list.add("数据内容");
                list.add(0, "新添加的数据");
                //刷新适配器
                adapter.notifyDataSetChanged();
            }
        });
    }

}

效果图：
        

站长苏飞

我只是路过打酱油的。

竹林风

感恩无私的分享与奉献

范范

强烈支持楼主ing……

惜

看到这帖子真是高兴！