Android listview点赞问题分析

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

package com.gz.test_listview;

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

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Created by gz on 2016/11/9.
 */
public class MainActivityAdapter extends BaseAdapter{
//用来获取界面上的元素
  private ViewHolder holder;
  private Context context;
  //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
  private List<Bean> praise_step_num = new ArrayList<Bean>();

  private LayoutInflater inflater;
  //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
  */
  private Map<Integer, Boolean> isExist = new HashMap<Integer, Boolean>();

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

  private void init() {
    /*
    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 (int i = 0;i<listItems.size();i++){
      isExist.put(i,false);
      Bean b = new Bean();
      Integer praise = Integer.parseInt(listItems.get(i).get("praise").toString());
      b.setPraise(praise);
      Integer step = 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
  public int getCount() {
    return listItems.size() ;
  }

  @Override
  public Object getItem(int position) {
    return position;
  }

  @Override
  public long getItemId(int position) {
    return position;
  }

  @Override
  public View getView(final int position, View convertView, ViewGroup parent) {
    //获取赞、踩得值
    final Bean bean = praise_step_num.get(position);

    if(convertView == null){
      holder = new ViewHolder();
      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(new imgClick(position,bean));

    return convertView;
  }

  class imgClick implements View.OnClickListener {
    private int position;
    private Bean bean;

    public imgClick(int position,Bean bean){
      this.position = position;
      this.bean = bean;
    }
    @Override
    public void onClick(final View v) {
      Log.i("position",position+"");
      if(bean.getPraise()==0){
        if(isExist.get(position) == false){
          final Handler handler = new Handler() {
            @Override
            public void handleMessage(Message msg) {
              super.handleMessage(msg);
              switch (msg.what){
                case 1:
                  ImageView btn = (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;
                  }
                case 2:
                  Toast.makeText(context, "失败", Toast.LENGTH_LONG).show();
                  break;
              }
            }
          };
          new Thread(){
            @Override
            public void run() {
              Message msg = new Message();
              msg.what=1;
              handler.sendMessage(msg);
            }
          }.start();
        }
      }else{
        Toast.makeText(context, "已经点击过", Toast.LENGTH_LONG).show();
      }
    }
  }

  private static class ViewHolder{
    public ImageView img_praise;

    public ImageView getImg_praise() {
      return img_praise;
    }

    public ImageView getImg_step() {
      return img_step;
    }

    public TextView getPraise() {
      return praise;
    }

    public TextView getStep() {
      return step;
    }

    public TextView getTitle() {
      return title;
    }

    private ImageView img_step;
    public TextView praise;
    private TextView step;
    private TextView title;

  }

  class Bean{
    public int getPraise() {
      return praise;
    }

    public void setPraise(int praise) {
      this.praise = praise;
    }

    public int getStep() {
      return step;
    }

    public void setStep(int step) {
      this.step = step;
    }

    private int praise;
    private int step;

  }
}

MainActivity

进行Listview值赋值，然后进行和Adapter的绑定

package com.gz.test_listview;

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

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;

public class MainActivity extends Activity {

  private ListView listview;
  private String[] title = {"商用","家用","测试","多联","空气能","商用","家用","测试","多联","空气能"};
  private String[] praise = {"3","1","0","0","0","3","1","0","0","0"};
  private String[] step = {"3","0","0","0","0","3","0","0","0","0"};

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

  private ListView listView;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    listview = (ListView) findViewById(R.id.listview);
    for(int i=0;i<title.length;i++){
      Map<String,Object> item = new HashMap<String,Object>();
      item.put("title",title[i]);
      item.put("praise",praise[i]);
      item.put("step",step[i]);
      map.add(item);
    }

    MainActivityAdapter adapter = new MainActivityAdapter(this,map);

    listview.setAdapter(adapter);
    listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
      @Override
      public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        Intent intent = new Intent(MainActivity.this,DetailActivity.class);
        startActivity(intent);
      }
    });

  }
}

跳转界面，测试用

package com.gz.test_listview;

import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

public class DetailActivity extends Activity {

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

简单的动画效果的实现

直接用就好了

package com.gz.test_listview;

import android.view.View;
import android.view.animation.Animation;
import android.view.animation.ScaleAnimation;

public class AnimationTools {
  public static void scale(View v) {
    ScaleAnimation anim = new ScaleAnimation(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

<?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: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

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns: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

<?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: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：http://www.jb51.net/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我们。