Android ListView控件的使用

Posted 2020-09-14 高山流水

     如何做出下面的效果：

       

 一、 先看下主界面的布局activity_main.xml：toolbar + ListView

<?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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.ahcc08.ahcc08.listviewdemo.MainActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_height="wrap_content"
        android:layout_width="match_parent"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay" />
    </android.support.design.widget.AppBarLayout>
    <ListView
        android:id="@+id/listview"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1">
    </ListView>
</LinearLayout>

二、新建一个用于显示ListView的Item布局：list_item.xml

<?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">
    <RelativeLayout
        android:id="@+id/ral_p1"
        android:layout_width="match_parent"
        android:layout_height="60dp" >
        <ImageView
            android:id="@+id/iv_p1"
            android:layout_width="35dp"
            android:layout_height="29dp"
            android:layout_centerVertical="true"
            android:layout_marginLeft="3dp"
            android:src="@drawable/hot" />

        <TextView
            android:id="@+id/title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:layout_marginLeft="13dp"
            android:layout_toRightOf="@+id/iv_p1"
            android:text="listitem"
            android:textSize="16sp" />

        <ImageView
            android:layout_width="12dp"
            android:layout_height="14.5dp"
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true"
            android:layout_marginRight="15dp"
            android:src="@drawable/info_go" />

        <View
            android:layout_width="match_parent"
            android:layout_height="1dp"
            android:layout_alignParentBottom="true"
            android:background="#ff00c0ff" />
    </RelativeLayout>
</LinearLayout>

三、主界面实现：MainActivity.java

package com.ahcc08.ahcc08.listviewdemo;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;

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

public class MainActivity extends AppCompatActivity {

    List<String> myList = new ArrayList<String>();

    ListView listview;
    MyListAdapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        initList();

        // 取得ListView控件
        listview = (ListView) findViewById(R.id.listview);
        // 新建一个适配器
        adapter = new MyListAdapter(MainActivity.this, myList);
        listview.setAdapter(adapter);
        listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                                    int position, long id) {
                String text = myList.get(position);
                Toast.makeText(MainActivity.this, text, Toast.LENGTH_SHORT).show();
            }
        });
    }

    private void initList() {
        myList.clear();
        for (int i = 0; i < 10; i++) {
            myList.add("item " + i);
        }
    }
}

四、适配器的实现：MyListAdapter.java

package com.ahcc08.ahcc08.listviewdemo;

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

import java.util.List;

public class MyListAdapter extends BaseAdapter {

    LayoutInflater inflater=null;
    List<String> mListData;

    public MyListAdapter(Context context , List<String> mListData) {
        super();
        inflater = LayoutInflater.from(context);
        this.mListData = mListData;
    }

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

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

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder vh = null;
        if (convertView == null){
            convertView = inflater.inflate(R.layout.list_item,parent,false);
            vh = new ViewHolder();
            vh.tv_title = (TextView) convertView.findViewById(R.id.title);
            convertView.setTag(vh);
        }else{
            vh = (ViewHolder) convertView.getTag();
        }

        String sInfo = (String) getItem(position);
        vh.tv_title.setText(sInfo);
        return convertView;
    }

    public void addAll(List<String> list,boolean isClear){
        if(isClear){
            mListData.clear();
            mListData.addAll(list);
        }else{
            mListData.addAll(list);
        }
        notifyDataSetChanged();
    }

    public void add(String t){
        mListData.add(t);
        notifyDataSetChanged();
    }

    public void remove(String t){
        mListData.remove(t);
        notifyDataSetChanged();
    }

    public void clear(){
        mListData.clear();
        notifyDataSetChanged();
    }

    class ViewHolder{
        TextView tv_title;
    }
}

代码比较简单吧。