Android ListView

listview的三种适配器

arrayadapter 支持list集合，只能展现一行文字

simpleadapter 具有扩展性，可以自定义多种效果

baseadapter 抽象类，继承这个类并且重写相关方法

常用属性

android:divider 设置分割线的颜色或图片

android:divider 分割线

android:scrollbars="none" 不显示滚动条

android:fadingedge="none" 去掉上边和下边黑色的阴影

android:fastscrollenable="true" 设置快速滚动

android:drawselectorontop="true" 设置长按试背景色高亮

android:stackfrombottom="true" 显示列表在最下面

android:cachecolorhint=“#000000” 设置背景时消除拖动的黑色阴影

android:headerdividersenabled=“false” 不会在页眉画分割线

android:footerdividersenabled=“false” 不会在页脚画分割线

android:descendantfocusability="blocksdescendants" 给子view设置，取消子控件的焦点

arrayadapter

1.系统自带布局

simple_list_item_1 : 单独一行的文本框，常用

simple_list_item_2 : 两个文本框组成

simple_list_item_checked : 每项都是由一个已选中的列表项 慎用

imple_list_item_multiple_choice : 都带有一个复选框 慎用

simple_list_item_single_choice : 都带有一个单选钮 慎用

setchoicemode(listview.choice_mode_multiple_modal) 设置多选状态 慎用

2.实例

listview.setadapter(new arrayadapter<string>(this,
                android.r.layout.simple_list_item_multiple_choice,new string[]{"元旦","清明","劳动节","端午节","中秋节"}));

 simpleadapter

list<map<string, object>> mlist = new arraylist<map<string, object>>();
for (int i = 0; i < idcard.length; i++) {
        map<string, object> map = new hashmap<string, object>();
        map.put("name", idcard[i]);
        map.put("sex",  "sex"+i);
        map.put("number","number"+i);
        list.add(map);
}


simpleadapter adapter = new simpleadapter(this, mlist,
                       r.layout.item_listview, new string[] { "name", "sex","number" }, 
　　　　　　　　　　　　 　newint[] {r.id.listview_item_name,r.id.listview_item_sex,r.id.listview_item_number });

自定义baseadapter模板

class myadapter extends baseadapter {
    private context context = null;
    public myadapter(context context) {
            this.context = context;
    }
    @override
    public int getcount() {
            return list.size();
    }
    @override
    public object getitem(int position) {
            return list.get(position);
    }
    @override
    public long getitemid(int position) {
            return position;
    }
    @override
    public view getview(int position, view convertview, viewgroup parent) {
            viewholder mholder;
            if (convertview == null) {
                    mholder = new viewholder();
                    layoutinflater inflater = layoutinflater.from(context);
                    convertview = inflater.inflate(r.layout.item_listview, null, true);
                    mholder.text_item_listview_username = (textview) convertview.findviewbyid(r.id.listview_item_name);
                    mholder.text_item_listview_email = (textview) convertview.findviewbyid(r.id.listview_item_sex);
                    mholder.imageview_item_listview_headpic = (imageview) convertview.findviewbyid(r.id.listview_item_number);
                    convertview.settag(mholder);
            } else {
                    mholder = (viewholder) convertview.gettag();
            }
            string name = list.get(position).get("name").tostring();
            string sex = list.get(position).get("sex").tostring();
            string number = list.get(position).get("number").tostring();

　　　　　　　mholder.listview_item_name.settext(name);
            mholder.listview_item_sex.settext(sex);
            mholder.listview_item_number.settext(number);
            return convertview;
    }

    class viewholder {
            private textview listview_item_name;
            private textview listview_item_sex;
            private textview listview_item_number;
    }
}

实现上拉刷新功能的listview

1.自定义adapter

public class mylistview extends listview implements onscrolllistener{
    
    private footlayout flayout;
    private scroller scroller;
    private listviewlistener lvlistener;
    private float mlasty;
    private int itemconut=-1;
    private int pull_load_more_delta=150;
    private int scroll_duration=400;
    public mylistview(context context) {
        super(context);
        initview(context);
        // todo auto-generated constructor stub
    }
    public mylistview(context context, attributeset attrs) {
        super(context, attrs);
        initview(context);
        // todo auto-generated constructor stub
    }
    public mylistview(context context, attributeset attrs, int defstyle) {
        super(context, attrs, defstyle);
        initview(context);
        // todo auto-generated constructor stub
    }
    public void initview(context context){
        super.setonscrolllistener(this);
        scroller=new scroller(context, new decelerateinterpolator());
        flayout= new footlayout(context);
        flayout.setstate(footlayout.state_no);
        flayout.setonclicklistener(new onclicklistener() {
            @override
            public void onclick(view arg0) {
                // todo auto-generated method stub
                statrview();
            }
        });
    }
    @override
    public void setadapter(listadapter adapter) {
        // todo auto-generated method stub
        addfooterview(flayout);
        super.setadapter(adapter);
    }
    public void statrview(){
        flayout.setstate(footlayout.state_loading);
        if(lvlistener!=null){
            lvlistener.onloadmore();
        }
    }
    public void stopview(){
        flayout.setstate(footlayout.state_no);
    }
    @override
    public boolean ontouchevent(motionevent ev) {
        // todo auto-generated method stub
        switch (ev.getaction()) {
            case motionevent.action_down:
                mlasty=ev.getrawy();
                break;
            case motionevent.action_move:
                final float deltay=ev.getrawy()-mlasty;
                mlasty=ev.getrawy();
                if(getlastvisibleposition()==itemconut-1){
                    updatefooterheight(-deltay);
                }
                break;
            default:
                if (getlastvisibleposition() == itemconut - 1) {
                    
                    // 调用加载更多
                    if (flayout.getbottommargin() > pull_load_more_delta) {
                        statrview();// 如果底部视图高度大于可以加载高度，那么就开始加载
                    }
                    resetfooterheight();// 重置加载更多视图高度
                }
                break;
        }
        return super.ontouchevent(ev);
    }
    private void updatefooterheight(float arg0){
        int height=flayout.getbottommargin()+(int)arg0;
            if (height > pull_load_more_delta) { 
                flayout.setstate(footlayout.state_ready);
            } else {
                flayout.setstate(footlayout.state_no);
            }
        flayout.setbottommargin(height);
    }
    private void resetfooterheight() {
        int bottommargin = flayout.getbottommargin();
        if (bottommargin > 0) {
            scroller.startscroll(0, bottommargin, 0, -bottommargin,
                    scroll_duration);
            invalidate();
        }
    }
    @override
    public void computescroll() {
        if (scroller.computescrolloffset()) {
            flayout.setbottommargin(scroller.getcurry());
            postinvalidate();
        }
        super.computescroll();
    }
    public interface listviewlistener {
        public void onloadmore();
    }
    public void setlistviewlistener(listviewlistener l) {
        lvlistener=l;
    }
    @override
    public void onscroll(abslistview arg0, int arg1, int arg2, int arg3) {
        // todo auto-generated method stub
        itemconut=arg3;
    }
    @override
    public void onscrollstatechanged(abslistview arg0, int arg1) {
        // todo auto-generated method stub
    }
    
}

2.底部footlayout

public class footlayout extends linearlayout{
    static int state_ready=0,state_loading=1,state_no=2;
    private relativelayout rlayout;
    private textview tv;
    private progressbar pb;
    public footlayout(context context, attributeset attrs, int defstyle) {
        super(context, attrs, defstyle);
        // todo auto-generated constructor stub
        initview(context);
    }
    public footlayout(context context) {
        super(context);
        // todo auto-generated constructor stub
        initview(context);
    }
    public void initview(context context){
        linearlayout layout=(linearlayout) layoutinflater.from(context).inflate(r.layout.foot_view, null);
        addview(layout);
        layout.setlayoutparams(new linearlayout.layoutparams(layoutparams.match_parent, 
            layoutparams.wrap_content));
        rlayout=(relativelayout) layout.findviewbyid(r.id.foot_rlayout);
        tv=(textview) layout.findviewbyid(r.id.foot_text);
        pb=(progressbar) layout.findviewbyid(r.id.foot_progressbar);
    }
    public void hide(){
        rlayout.setvisibility(view.visible);
    }
    public void show(){
        rlayout.setvisibility(view.invisible);
    }
    public void setstate(int state){
        tv.setvisibility(view.invisible);
        pb.setvisibility(view.invisible);
        if(state==state_ready){
            tv.setvisibility(view.visible);
            tv.settext("松开显示更多");
        }else if(state==state_loading){
            pb.setvisibility(view.visible);
        }else{
            tv.setvisibility(view.visible);
            tv.settext("加载更多");
        }
    }
    public void setbottommargin(int height) {
        if (height < 0)
            return;
        linearlayout.layoutparams lp = (linearlayout.layoutparams) rlayout
                .getlayoutparams();
        lp.bottommargin = height;
        rlayout.setlayoutparams(lp);
    }

    public int getbottommargin() {
        linearlayout.layoutparams lp = (linearlayout.layoutparams) rlayout
                .getlayoutparams();
        return lp.bottommargin;
    }
}

3.底部footlayout的布局

<?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/foot_rlayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        >
        <textview 
            android:id="@+id/foot_text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="加载更多"
            android:layout_centerinparent="true"
            />
        <progressbar 
            android:id="@+id/foot_progressbar"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerinparent="true"
            android:verticalscrollbarposition="defaultposition"
            android:visibility="invisible"
            />
        
        
    </relativelayout>

</linearlayout>

4.使用mylistview

public class mainactivity extends activity implements ixlistviewlistener{
    private listviews mylists;
    private simpleadapter madapter;
    private list<map<string,object>> mlist;
    private handler mhandler;   
    @override  
    protected void oncreate(bundle savedinstancestate) {
        super.oncreate(savedinstancestate);
        setcontentview(r.layout.activity_main);  
        mylists =(listviews) findviewbyid(r.id.mylistview);
        mlist=new arraylist<map<string,object>>();
        madapter = new simpleadapter(mainactivity.this, getdata(),
                r.layout.list_item, new string[] { "name", "img", "content" },
                new int[] { r.id.title, r.id.mimage, r.id.content });
        mylists.setadapter(madapter);
        mylists.setpullloadenable(true);
        mylists.setxlistviewlistener(this);
        mhandler = new handler();
    }
    string data[] = new string[] { "勇士", "火箭", "湖人",
            "凯尔特人", "雷霆" };
    string data1[] = new string[] { "汤普森", "哈登", "詹姆斯",
            "塔图姆", "维斯布鲁克" };

    private list<map<string, object>> getdata() {
        for (int i = 0; i < data.length; i++) {
            map<string, object> map = new hashmap<string, object>();
            map.put("name", data[i]);
            map.put("content", data1[i]);
            map.put("img", r.drawable.ic_launcher);
            mlist.add(map);
        }
        return mlist;
    }  
        // 加载更多
        @override
        public void onloadmore() {
            mhandler.postdelayed(new runnable() {
                @override
                public void run() {
                    getdata();
                    madapter.notifydatasetchanged();
                    onload();
                }
            }, 1500);  
        }
        private void onload() {
            mylists.stoploadmore();
        }
}