Android listview点赞问题分析

2024-03-09 12:03:03 156

最近这段时间一直在看Android，利用Listview去实现点赞功能

基本思路：

进入界面–》获取数据–》
在Listview中显示–》
通过map集合（position,boolean）保存每一行是否被点击–》
利用实体类去保存相应的对象–》
get/set方法进行相应值得改变–》
点击一次，相应的数量加1

只实现了点赞功能，踩和赞基本类似。

具体实现如下：

继承自BaseAdapter

packagecom.gz.test_listview;

importandroid.content.Context;
importandroid.content.DialogInterface;
importandroid.content.Intent;
importandroid.os.Handler;
importandroid.os.Message;
importandroid.util.Log;
importandroid.view.LayoutInflater;
importandroid.view.View;
importandroid.view.ViewGroup;
importandroid.widget.AdapterView;
importandroid.widget.BaseAdapter;
importandroid.widget.Button;
importandroid.widget.ImageView;
importandroid.widget.ListView;
importandroid.widget.TextView;
importandroid.widget.Toast;

importjava.util.ArrayList;
importjava.util.HashMap;
importjava.util.List;
importjava.util.Map;

/**
*Createdbygzon2016/11/9.
*/
publicclassMainActivityAdapterextendsBaseAdapter{
//用来获取界面上的元素
privateViewHolderholder;
privateContextcontext;
//这里的Bean是个测试用的内部类，将点赞数和踩得数存起来，可以定义一个类，
//直接获取数据就好，需要改进下
privateList<Bean>praise_step_num=newArrayList<Bean>();

privateLayoutInflaterinflater;
//保存当前点赞数
List<Map<String,Object>>listItems;
/*
根据position，保存点击的是哪一行数据，默认为false，点击后改为true
*/
privateMap<Integer,Boolean>isExist=newHashMap<Integer,Boolean>();

publicMainActivityAdapter(Contextcontext,List<Map<String,Object>>listItems){
this.context=context;
this.listItems=listItems;
inflater=LayoutInflater.from(context);
Log.i("listItem",listItems.toString());
init();
}

privatevoidinit(){
/*
为相应的数据赋值，所有的数据存储在listItems中
position一一对应每一行数据
*/
for(inti=0;i<listItems.size();i++){
isExist.put(i,false);
Beanb=newBean();
Integerpraise=Integer.parseInt(listItems.get(i).get("praise").toString());
b.setPraise(praise);
Integerstep=Integer.parseInt(listItems.get(i).get("step").toString());
b.setStep(step);
praise_step_num.add(i,b);
Log.i("praise_step",praise_step_num.get(i).getPraise()+"");
}

}

@Override
publicintgetCount(){
returnlistItems.size();
}

@Override
publicObjectgetItem(intposition){
returnposition;
}

@Override
publiclonggetItemId(intposition){
returnposition;
}

@Override
publicViewgetView(finalintposition,ViewconvertView,ViewGroupparent){
//获取赞、踩得值
finalBeanbean=praise_step_num.get(position);

if(convertView==null){
holder=newViewHolder();
convertView=inflater.inflate(R.layout.item_praise,null);
holder.img_praise=(ImageView)convertView.findViewById(R.id.tv_praises_img);
holder.img_step=(ImageView)convertView.findViewById(R.id.tv_step_img);
holder.praise=(TextView)convertView.findViewById(R.id.tv_praises);
holder.step=(TextView)convertView.findViewById(R.id.tv_step);
holder.title=(TextView)convertView.findViewById(R.id.tv_name);


//holder.img_step.setImageResource(R.drawable.bad);



convertView.setTag(holder);
}else{
holder=(ViewHolder)convertView.getTag();
}

holder.praise.setText(bean.getPraise()+"");
holder.step.setText(bean.getStep()+"");
holder.title.setText(listItems.get(position).get("title")+"");
/*
每次会复用convertView,
convertView没有被赋值，就会使用之后赋值的数据，
比如：点击了第一行数据赞的按钮，相应的第一行点赞图片变为红色
当向下滑动页面时，下方的也会有一项数据发生变化，复用
在这里为每次重用赋值
*/
if(bean.getPraise()!=0){
holder.img_praise.setImageResource(R.drawable.good);
}else{
holder.img_praise.setImageResource(R.drawable.good_no);
}
if(bean.getStep()!=0){
holder.img_step.setImageResource(R.drawable.bad);
}else{
holder.img_step.setImageResource(R.drawable.bad_no);
}


holder.img_praise.setOnClickListener(newimgClick(position,bean));

returnconvertView;
}

classimgClickimplementsView.OnClickListener{
privateintposition;
privateBeanbean;

publicimgClick(intposition,Beanbean){
this.position=position;
this.bean=bean;
}
@Override
publicvoidonClick(finalViewv){
Log.i("position",position+"");
if(bean.getPraise()==0){
if(isExist.get(position)==false){
finalHandlerhandler=newHandler(){
@Override
publicvoidhandleMessage(Messagemsg){
super.handleMessage(msg);
switch(msg.what){
case1:
ImageViewbtn=(ImageView)v;
if(v.getId()==btn.getId()){
isExist.put(position,true);
bean.setPraise(bean.getPraise()+1);
btn.setImageResource(R.drawable.good);
AnimationTools.scale(btn);
notifyDataSetChanged();
break;
}
case2:
Toast.makeText(context,"失败",Toast.LENGTH_LONG).show();
break;
}
}
};
newThread(){
@Override
publicvoidrun(){
Messagemsg=newMessage();
msg.what=1;
handler.sendMessage(msg);
}
}.start();
}
}else{
Toast.makeText(context,"已经点击过",Toast.LENGTH_LONG).show();
}
}
}

privatestaticclassViewHolder{
publicImageViewimg_praise;

publicImageViewgetImg_praise(){
returnimg_praise;
}

publicImageViewgetImg_step(){
returnimg_step;
}

publicTextViewgetPraise(){
returnpraise;
}

publicTextViewgetStep(){
returnstep;
}

publicTextViewgetTitle(){
returntitle;
}

privateImageViewimg_step;
publicTextViewpraise;
privateTextViewstep;
privateTextViewtitle;


}

classBean{
publicintgetPraise(){
returnpraise;
}

publicvoidsetPraise(intpraise){
this.praise=praise;
}

publicintgetStep(){
returnstep;
}

publicvoidsetStep(intstep){
this.step=step;
}

privateintpraise;
privateintstep;

}
}

MainActivity

进行Listview值赋值，然后进行和Adapter的绑定

packagecom.gz.test_listview;

importandroid.app.Activity;
importandroid.content.Intent;
importandroid.support.v7.app.AppCompatActivity;
importandroid.os.Bundle;
importandroid.view.View;
importandroid.widget.AdapterView;
importandroid.widget.ListView;

importjava.util.ArrayList;
importjava.util.HashMap;
importjava.util.List;
importjava.util.Map;
importjava.util.Objects;

publicclassMainActivityextendsActivity{

privateListViewlistview;
privateString[]title={"商用","家用","测试","多联","空气能","商用","家用","测试","多联","空气能"};
privateString[]praise={"3","1","0","0","0","3","1","0","0","0"};
privateString[]step={"3","0","0","0","0","3","0","0","0","0"};

privateArrayList<Map<String,Object>>map=newArrayList<Map<String,Object>>();

privateListViewlistView;
@Override
protectedvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listview=(ListView)findViewById(R.id.listview);
for(inti=0;i<title.length;i++){
Map<String,Object>item=newHashMap<String,Object>();
item.put("title",title[i]);
item.put("praise",praise[i]);
item.put("step",step[i]);
map.add(item);
}

MainActivityAdapteradapter=newMainActivityAdapter(this,map);

listview.setAdapter(adapter);
listview.setOnItemClickListener(newAdapterView.OnItemClickListener(){
@Override
publicvoidonItemClick(AdapterView<?>parent,Viewview,intposition,longid){
Intentintent=newIntent(MainActivity.this,DetailActivity.class);
startActivity(intent);
}
});

}
}

跳转界面，测试用

packagecom.gz.test_listview;

importandroid.app.Activity;
importandroid.os.Bundle;
importandroid.widget.ListView;

importjava.util.ArrayList;
importjava.util.HashMap;
importjava.util.Map;

publicclassDetailActivityextendsActivity{


@Override
protectedvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.detail_info);
}
}

简单的动画效果的实现

直接用就好了

packagecom.gz.test_listview;

importandroid.view.View;
importandroid.view.animation.Animation;
importandroid.view.animation.ScaleAnimation;

publicclassAnimationTools{
publicstaticvoidscale(Viewv){
ScaleAnimationanim=newScaleAnimation(1.0f,1.5f,1.0f,1.5f,
Animation.RELATIVE_TO_SELF,0.5f,Animation.RELATIVE_TO_SELF,
0.5f);
anim.setDuration(300);
v.startAnimation(anim);

}
}

界面

<?xmlversion="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:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context="com.gz.test_listview.MainActivity">

<ListView
android:id="@+id/listview"
android:layout_width="match_parent"
android:layout_height="wrap_content">


</ListView>
</RelativeLayout>

Listview子项

<?xmlversion="1.0"encoding="utf-8"?>
<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/lyt_root"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ccc"
android:orientation="vertical"
android:descendantFocusability="blocksDescendants"
>
<FrameLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content">


<ImageView
android:id="@+id/has_exame"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="top|left"
/>

<LinearLayout
android:layout_margin="10dip"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:background="@drawable/corners"
android:layout_weight="1.0"
android:orientation="vertical"
>

<TextView
android:id="@+id/tv_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="14sp"
android:text="商用多联机"
android:textColor="#000"
/>

<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">

<TextView
android:id="@+id/tv_date"
android:layout_marginTop="10dip"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="12sp"
android:text="时间2016-10-10"
android:textColor="#000"
android:visibility="visible"
/>

<TextView
android:id="@+id/tv_downloads"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_weight="1"
android:textColor="#000"
android:textSize="14sp"
android:visibility="gone"/>


</LinearLayout>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:gravity="center|right"
>

<ImageView
android:id="@+id/tv_praises_img"
android:layout_width="30dip"
android:layout_height="30dip"
android:background="@drawable/good_no"
android:layout_marginRight="5dip"
/>
<TextView
android:id="@+id/tv_praises"
android:layout_width="50dip"
android:layout_height="wrap_content"
android:textColor="#000"
android:text="10"
android:textSize="14dip"
android:layout_gravity="center"
/>

<ImageView
android:id="@+id/tv_step_img"
android:layout_width="30dip"
android:layout_height="30dip"
android:background="@drawable/bad_no"
android:layout_marginRight="5dip"

/>
<TextView
android:id="@+id/tv_step"
android:layout_width="50dip"
android:layout_height="wrap_content"
android:textColor="#000"
android:text="10"
android:textSize="14dip"
android:layout_gravity="center"
/>

</LinearLayout>

</LinearLayout>


</FrameLayout>

</LinearLayout>

点击item后进入的界面

<?xmlversion="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:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
android:orientation="vertical"
>

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="111"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="111"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="111"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="111"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="111"
/>


</LinearLayout>

代码中是我对程序的理解，有的地方可能不是很明白，还得完善完善
这篇文章给了我很大帮助，动画效果就是搬过来的，哈哈，很不错，学习了。

参考文章：https://www.nhooo.com/article/97335.htm

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持毛票票。

Android listview点赞问题分析

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