listview的使用及自定义baseAdapter

雨点打透心脏的1/2处 2022-10-01 00:39 200阅读 0赞

整个编码步骤如下：

1.首先编写一个main\_activity.xml，在其中加入listview控件；

2.编写listview中子项要展示数据的布局文件item.xml；

3.编写MyTest类（这里为自己根据需求编写需要的类）\{

无参和有参构造函数；

getter和setter方法；

/**
     * Created by Administrator on 2017/3/23.
     */
    
    public class MyTest{
        private String Title;
        private String Context;
        private int icon;
    
        public MyTest(){
    
        }
    
        public MyTest(String Title,String Context,int icon){
            this.Title=Title;
            this.Context=Context;
            this.icon=icon;
        }
    
        public String getTitle() {
            return Title;
        }
    
        public void setTitle(String title) {
            Title = title;
        }
    
        public String getContext() {
            return Context;
        }
    
        public void setContext(String context) {
            Context = context;
        }
    
        public int getIcon() {
            return icon;
        }
    
        public void setIcon(int icon) {
            this.icon = icon;
        }
    }

\};

4.编写MyBaseAdapter类

/**
     * Created by Administrator on 2017/3/23.
     */
    
    public class MyAdapter extends BaseAdapter{
        private LinkedList<MyTest> mData;
        private Context mContext;
    
        public MyAdapter(LinkedList<MyTest> mData, Context mContext) {
            this.mData = mData;
            this.mContext = mContext;
        }
        @Override
        public int getCount() {
            return mData.size();
        }
    
        @Override
        public Object getItem(int i) {
            return null;
        }
    
        @Override
        public long getItemId(int i) {
            return i;
        }
    
        @Override
        public View getView(int i, View view, ViewGroup viewGroup) {
            view = LayoutInflater.from(mContext).inflate(R.layout.item,viewGroup,false);//加载布局管理器，将xml布局转换为view对象
            ImageView img_icon = (ImageView) view.findViewById(R.id.pic);//利用view对象找到布局中的组件
            TextView txt_title = (TextView) view.findViewById(R.id.title);
            TextView txt_context = (TextView) view.findViewById(R.id.context);
            img_icon.setBackgroundResource(mData.get(i).getIcon());
            txt_title.setText(mData.get(i).getTitle());
            txt_context.setText(mData.get(i).getContext());
            return view;
        }
    }

5.编写MainActivity.java

①加载要显示的数据；

②.调用ListView的setAdapter()方法，将构建好的适配器对象传递进去，这样ListView和数据之间关联就建立完成了。

public class MainActivity extends AppCompatActivity {
        private List<MyTest> mData = null;
        private MyAdapter mAdapter = null;
        private ListView listView;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            listView = (ListView) findViewById(R.id.listview);
            mData = new LinkedList<MyTest>();
            mData.add(new MyTest("我是标题1", "我是内容", R.mipmap.ic_launcher));
            mData.add(new MyTest("我是标题2", "我是内容", R.mipmap.ic_launcher));
            mData.add(new MyTest("我是标题3", "我是内容", R.mipmap.ic_launcher));
            mData.add(new MyTest("我是标题4", "我是内容", R.mipmap.ic_launcher));
            mData.add(new MyTest("我是标题5", "我是内容", R.mipmap.ic_launcher));
            mAdapter = new MyAdapter((LinkedList<MyTest>) mData,MainActivity.this);
            listView.setAdapter(mAdapter);
            }
    }

运行结果：

![Center][]

[Center]: /images/20220705/7879c0bb9f344bfebed822011b2637c6.png