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Android SimpleAdapter应用介绍,代码+解释 ListView使用+滚动监听用scoll

2016-07-01 16:26 483 查看
MainActivity的文件代码:

package com.example.myapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
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;
import java.util.Objects;

public class MainActivity extends AppCompatActivity implements AdapterView.OnItemClickListener, AbsListView.OnScrollListener {
private ListView listView;
private SimpleAdapter simpleAdapter;
private List<Map<String,Object>> dataList;

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

dataList = new ArrayList<Map<String, Object>>();

listView = (ListView) findViewById(R.id.listView);
simpleAdapter = new SimpleAdapter(this,getData(),R.layout.tem,new String[]{"pic","text"},new int[]{R.id.pic,R.id.text});

listView.setAdapter(simpleAdapter);
listView.setOnItemClickListener(this);
listView.setOnScrollListener(this);
}
private List<Map<String,Object>> getData()
{
for(int i = 0;i<20;i++)
{
Map<String,Object> map = new HashMap<String,Object>();
map.put("pic",R.mipmap.ic_launcher);
map.put("text","慕课网"+i);
dataList.add(map);
}
return dataList;
}

@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
String text = listView.getItemAtPosition(i)+"";
Toast.makeText(this,"position = " + i +"text" + text,Toast.LENGTH_SHORT).show();
}

@Override
public void onScrollStateChanged(AbsListView absListView, int i) {

switch (i)
{
case SCROLL_STATE_FLING:
Log.i("Main", "用户在手指离开屏幕之前,由于用力滑了一下,师徒扔依靠惯性继续滑动: ");
Map<String,Object> map = new HashMap<String,Object>();
map.put("pic",R.mipmap.ic_launcher);
map.put("text","增加项");
dataList.add(map);
simpleAdapter.notifyDataSetChanged();
break;
case SCROLL_STATE_IDLE:
Log.i("Main", "视图已经停止滑动");
break;
case SCROLL_STATE_TOUCH_SCROLL:
Log.i("Main", "手指没有离开屏幕,视图正在滑动");
break;
}
}

@Override
public void onScroll(AbsListView absListView, int i, int i1, int i2) {

}
}


activity_main的代码:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.myapplication.MainActivity">

<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/listView"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
</RelativeLayout>


最后建立,listview的子项目布局:

命名为tem:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:orientation="horizontal"
android:layout_height="match_parent">
<ImageView
android:id="@+id/pic"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@mipmap/ic_launcher"/>
<TextView
android:id="@+id/text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="慕课网"/>

</LinearLayout>
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