列表视图ListView

依然是一个listView的Java文件

public class ListViewActivity extends Activity {
    private ListView lv1;
    @Override
    protected void onCreate(@Nullable Bundle savedInstenceState) {

        super.onCreate(savedInstenceState);
        setContentView(R.layout.activity_listview);
        lv1=findViewById(R.id.lv_1);
        lv1.setAdapter(new MylistAdapter(ListViewActivity.this));
        lv1.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                Toast.makeText(ListViewActivity.this, "点击pos:"+i, Toast.LENGTH_SHORT).show();
            }
        });
        lv1.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClick(AdapterView<?> adapterView, View view, int i, long l) {
                Toast.makeText(ListViewActivity.this, "长按pos:"+i, Toast.LENGTH_SHORT).show();
                return true;//这里如果返回false的话，处理完长按事件后还会处理点击事件，也就是说会弹出两个提示框，为了让他只显示一个对话框改为true
            }
        });
    }
}

 

对应的activity_listview.xml文件

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ListView
        android:id="@+id/lv_1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:listSelector="@drawable/list_item"/>
        <!-- 这里listSelector设置的是点击样式，效果-->

</LinearLayout>

其中设置的点击效果xml文件为

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true" android:drawable="@color/purple_200"/>
    <item android:drawable="@color/touming"/>
</selector>

这里面state_pressed和state_checked是不一样的，checked是选中的意思，pressed是按压时候的效果，注意区分。

然后layout_list_item.xml文件是设置list中每一个元素的样式结构的文件

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    android:padding="10dp">
    <ImageView
        android:id="@+id/imv"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:scaleType="centerCrop"
        android:background="#000"/>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:paddingLeft="10dp">
        <TextView
            android:id="@+id/tv_title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="你好你好"
            android:textColor="@color/black"
            android:textSize="20sp"/>
        <TextView
            android:id="@+id/tv_time"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="2022-01-28"
            android:textColor="@color/greydrak"
            android:paddingTop="10dp"
            android:textSize="17sp"/>
        <TextView
            android:id="@+id/tv_content"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="你好，我是内容"
            android:textColor="@color/greydrak"
            android:paddingTop="10dp"
            android:textSize="17sp"/>
    </LinearLayout>
</LinearLayout>

然后建立MyListAdapter的Java文件来定义列表中每个元素的具体结构的值：

public class MylistAdapter extends BaseAdapter {
    private Context context;
    private LayoutInflater layoutInflater;
    public MylistAdapter(Context context){
        this.context=context;
        layoutInflater=LayoutInflater.from(context);
    }
    @Override
    public int getCount() {
        return 10;
    }//列表长度

    @Override
    public Object getItem(int i) {
        return null;
    }//不怎么用

    @Override
    public long getItemId(int i) {
        return 0;
    }//不怎么用

    static class ViewHolder{
        public ImageView imageview;
        public TextView tvTitle,tvTime,tvContent;
    }

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        ViewHolder holder=null;
        if(view==null){
            view=layoutInflater.inflate(R.layout.layout_list_item,null);
            holder=new ViewHolder();
            holder.imageview=view.findViewById(R.id.imv);
            holder.tvTitle=view.findViewById(R.id.tv_title);
            holder.tvContent=view.findViewById(R.id.tv_content);
            holder.tvTime=view.findViewById(R.id.tv_time);
            view.setTag(holder);
        }else{
            holder= (ViewHolder) view.getTag();
        }
        //给控件赋值
        holder.tvTitle.setText("我是大标题");
        holder.tvTime.setText("2066-06-6");
        holder.tvContent.setText("说点啥呢啥呢");
        Glide.with(context).load("https://www.baidu.com/img/PCtm_d9c8750bed0b3c7d089fa7d55720d6cf.png").into(holder.imageview);
        return view;
    }
}