activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
tools:context="com.example.first.myapplication.MainActivity">
<ListView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/listview1"/>
</android.support.constraint.ConstraintLayout>
MainActivity.java
package com.example.first.myapplication;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class MainActivity extends Activity {
ListView listView;
ArrayAdapter<String>arradapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = this.findViewById(R.id.listview1);
/*
第一种适配器
1.新建一个适配器
第一个参数是 上下文
第二个参数是 当前listview所加载的每一个列表项所对应的布局文件
第三个参数是 我们所对应的数据源
*/
/*
适配器加载数据源
*/
String[] data1 = {"哈哈哈","呵呵呵","嘿嘿嘿"};
arradapter = new ArrayAdapter<String>(MainActivity.this , R.layout.item , data1);
/*
视图加载适配器
*/
listView.setAdapter(arradapter);
/*
事件监听器
*/
//点击列表项中单个条目的监听器
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
//position 当前点击的位置,也就是当前点击的条目,从0开始
public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
//当前点击的条目的内容
String text = listView.getItemAtPosition(position)+"";
Toast.makeText(MainActivity.this,"position="+position+"text="+text,Toast.LENGTH_SHORT).show();
}
});
//滚动变化时的监听器
listView.setOnScrollListener(new AbsListView.OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView absListView, int i) {
/*
i:滚动状态;
*/
switch (i){
case SCROLL_STATE_FLING:
Toast.makeText(MainActivity.this,"用户手指在离开屏幕之前,由于用力滑了一下,视图仍依靠惯性继续滚动",Toast.LENGTH_SHORT).show();
Map<String,Object>map = new HashMap<String,Object>();
map.put("img1",R.mipmap.ic_launcher);
map.put("txtv1","增加项");
datalist.add(map);
simpleAdapter.notifyDataSetChanged();
break;
case SCROLL_STATE_IDLE:
Toast.makeText(MainActivity.this,"视图已经停止滑动",Toast.LENGTH_SHORT).show();
break;
case SCROLL_STATE_TOUCH_SCROLL:
Toast.makeText(MainActivity.this,"用户手指没有离开屏幕,正在滑动",Toast.LENGTH_SHORT).show();
break;
}
}
@Override
public void onScroll(AbsListView absListView, int i, int i1, int i2) {
}
});
}
}