android 实现ListView嵌套Checkbox实现真正的多选、全选、反选、取消

android 实现listview嵌套checkbox实现真正的多选、全选、反选、取消

我们在开发app的时候，很多情况下会使用到listview嵌套checkbox的情况，例如购物车选择商品的情况，其实很多人要说这个其实很简单了，并没有那么复杂，事实上并非如此，我们在使用listview嵌套checkbox复选框的时候会出现很多问题，接下来我将用一篇博客来说明这些问题，给大家一些参照，解决listview嵌套checkbox解决复用问题。

????? ? 效果图如下：

首先，我们先看mainactivity中的布局,

接下来看mainactivity的代码如下：

package com.example.cx.listviewdemo;

import android.os.bundle;
import android.support.v7.app.appcompatactivity;
import android.view.view;
import android.widget.adapterview;
import android.widget.button;
import android.widget.listview;
import android.widget.toast;
import java.util.arraylist;
import java.util.list;

public class mainactivity extends appcompatactivity implements view.onclicklistener {

    private listview mlv;
    private button mbtnselectall, mbtnunselectall, mbtndelete, mbtncancel;
    //数据源
    private list mdatalist;

    //与条目对应的选中状态
    private list mcheckedlist;
    private myadapter madapter;
    
    
    @override
    protected void oncreate(bundle savedinstancestate) {
        super.oncreate(savedinstancestate);
        setcontentview(r.layout.activity_main);
        initview();
        mdatalist = new arraylist();
        mcheckedlist = new arraylist();

        for (int i = 0; i < 50; i++) {
            mdatalist.add("数据" + i);
            mcheckedlist.add(false);
        }
        madapter = new myadapter(mainactivity.this, mdatalist);
        madapter.setdata(mdatalist, mcheckedlist);
        mlv.setadapter(madapter);


        mlv.setonitemclicklistener(new adapterview.onitemclicklistener() {
            @override
            public void onitemclick(adapterview parent, view view, int position, long id) {
                toast.maketext(mainactivity.this, "条目" + position + "被点击了", toast.length_short).show();

                mcheckedlist.set(position, !mcheckedlist.get(position));
                madapter.setdata(mdatalist, mcheckedlist);
                madapter.notifydatasetchanged();

            }
        });
    }

    private void initview() {
        mlv = (listview) findviewbyid(r.id.lv);
        mbtnselectall = findviewbyid(r.id.btn_all_select);
        mbtnunselectall = findviewbyid(r.id.btn_all_unselect);
        mbtndelete = findviewbyid(r.id.btn_delete);
        mbtncancel = findviewbyid(r.id.btn_cancel);

        mbtnselectall.setonclicklistener(this);
        mbtnunselectall.setonclicklistener(this);
        mbtndelete.setonclicklistener(this);
        mbtncancel.setonclicklistener(this);
    }
    
    @override
    public void onclick(view v) {
        switch (v.getid()) {
            //全选
            case r.id.btn_all_select:
                select_all();
                break;

            //反选
            case r.id.btn_all_unselect:
                unselect_all();
                break;
                
            //删除
            case r.id.btn_delete:
                delete();
                break;

            //取消
            case r.id.btn_cancel:
                cancel();
                break;
        }
    }

    // 全选
    private void select_all() {
        for (int i = 0; i < mcheckedlist.size(); i++) {
            mcheckedlist.set(i, true);
        }
        madapter.setdata(mdatalist, mcheckedlist);
        madapter.notifydatasetchanged();
    }


    //取消
    private void cancel() {
        for (int i = 0; i < mcheckedlist.size(); i++) {
            mcheckedlist.set(i, false);
        }
        madapter.setdata(mdatalist, mcheckedlist);
        madapter.notifydatasetchanged();

    }

    //删除
    private void delete() {
        for (int i = 0; i < mcheckedlist.size(); i++) {
            if (mcheckedlist.get(i)) {
                mcheckedlist.remove(i);
                mdatalist.remove(i);
                i--;
            }
        }
        madapter.setdata(mdatalist, mcheckedlist);
        madapter.notifydatasetchanged();
    }

    //反选
    private void unselect_all() {
        for (int i = 0; i < mcheckedlist.size(); i++) {
            mcheckedlist.set(i, !mcheckedlist.get(i));
        }
        madapter.setdata(mdatalist, mcheckedlist);
        madapter.notifydatasetchanged();
    }
}

主要是adapter 的代码，里面解决了listview 嵌套checkbox的问题。比如，当选中item中的checkbox时然后上下滑动，这时你会发现item会被复用，什么意思呢？就是当你上下滑动listview时，选中的checkbox会被取消，这个问题跟listview加载图片时会错位一样，都是事件分发机制造成的，具体解决接下来看操作：

package com.example.cx.listviewdemo;

import android.content.context;
import android.content.sharedpreferences;
import android.view.view;
import android.view.viewgroup;
import android.widget.baseadapter;
import android.widget.checkbox;
import android.widget.compoundbutton;
import android.widget.textview;
import java.util.list;


public class myadapter extends baseadapter {
    private context mcontext;
    private list mdatalist;
    private list mcheckedlist;
    private sharedpreferences msp;

    public myadapter(context context, list mdatalist) {
        this.mcontext = context;
        this.mdatalist = mdatalist;
        msp = mcontext.getsharedpreferences("config", context.mode_private);
    }


    //会被多次调用(只要listview条目个数发生变化的时候)
    public void setdata(list datalist, list checkedlist) {
        this.mdatalist = datalist;
        this.mcheckedlist = checkedlist;
    }

    @override
    public int getcount() {
        return mdatalist.size();
    }

    @override
    public object getitem(int position) {
        return mdatalist.get(position);
    }

    @override
    public long getitemid(int position) {
        return position;
    }



    //图片错位： 给加载的图片设计tag(url)标记，复用之后再次滑动当前条目，判断当前图片url和这个tag标记是否一致，如果一致就显示，如果不一致就不显示

    @override
    public view getview(final int position, view convertview, viewgroup parent) {
        viewholder viewholder = null;
        if (viewholder == null) {
            viewholder = new viewholder();
            convertview = view.inflate(mcontext, r.layout.layout_list_item, null);
            viewholder.mtv = convertview.findviewbyid(r.id.item_tv);
            viewholder.mcb = convertview.findviewbyid(r.id.item_cb);
            convertview.settag(viewholder);

        } else {
            viewholder = (viewholder) convertview.gettag();
        }

        viewholder.mtv.settext(mdatalist.get(position));
        viewholder.mcb.setchecked(mcheckedlist.get(position));

        viewholder.mcb.setoncheckedchangelistener(new compoundbutton.oncheckedchangelistener() {
            @override
            public void oncheckedchanged(compoundbutton buttonview, boolean ischecked) {
                mcheckedlist.set(position, ischecked);
                notifydatasetchanged();
            }
        });

        return convertview;
    }


    public static class viewholder {
        textview mtv;
        checkbox mcb;
    }
}

这是适配器布局代码：

这样我们就实现了listview嵌套checkbox实现真正的多选、全选、反选、取消。