Android列表(ListView)

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mb5fd86caa0a310 2021-08-10 14:37:00

文章标签 Android android ico xml ide 文章分类 代码人生

效果图

Android列表(ListView)_xml

1.activity_main.xml页面

1         <ListView
2             android:layout_width="match_parent"
3             android:layout_height="460dp"
4             android:id="@+id/list_item">
5 
6         </ListView>

2.同级layout目录下创建一个item_list.xml页面，编辑布局

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     xmlns:app="http://schemas.android.com/apk/res-auto"
 4     xmlns:tools="http://schemas.android.com/tools"
 5     android:layout_width="match_parent"
 6     android:layout_height="match_parent"
 7     android:background="#fff"
 8     android:orientation="vertical"
 9     android:padding="10dp"
10    >
11 
12         <LinearLayout
13             android:layout_width="match_parent"
14             android:layout_height="wrap_content"
15             android:gravity="center_vertical"
16             >
17 
18 
19             <LinearLayout
20                 android:layout_width="0dp"
21                 android:layout_height="wrap_content"
22                 android:layout_weight="6"
23                 android:orientation="vertical"
24                 >
25 
26                 <TextView
27                     android:id="@+id/title"
28                     android:layout_width="wrap_content"
29                     android:layout_height="wrap_content"
30                     android:textColor="#000"
31                     android:textSize="18sp" />
32 
33                 <LinearLayout
34                     android:layout_width="wrap_content"
35                     android:layout_height="wrap_content"
36                     android:layout_marginTop="10dp"
37                     android:layout_marginBottom="10dp">
38 
39                     <ImageView
40                         android:id="@+id/icon"
41                         android:layout_width="20dp"
42                         android:layout_height="20dp"/>
43 
44                     <TextView
45                         android:layout_width="wrap_content"
46                         android:layout_height="wrap_content"
47                         android:id="@+id/warning"
48                         android:textColor="#cccc33"
49                         android:textSize="16sp" />
50                 </LinearLayout>
51 
52 
53                 <TextView
54                     android:id="@+id/time"
55                     android:layout_width="wrap_content"
56                     android:layout_height="wrap_content"
57                     android:textColor="#666"
58                     android:textSize="14sp" />
59 
60             </LinearLayout>
61 
62             <Button
63                 android:layout_width="0dp"
64                 android:layout_height="48dp"
65                 android:layout_weight="1"
66                 android:background="@drawable/radius"
67                 android:text="确认" />
68 
69         </LinearLayout>
70 
71 
72 </RelativeLayout>

3.MainActivity.java

 1 package com.rxy.machine.activity;
 2 
 3 import androidx.appcompat.app.AppCompatActivity;
 4 
 5 import android.os.Bundle;
 6 import android.view.View;
 7 import android.view.ViewGroup;
 8 import android.widget.BaseAdapter;
 9 import android.widget.ImageView;
10 import android.widget.ListView;
11 import android.widget.TextView;
12 
13 import com.rxy.machine.R;
14 
15 public class MovingActivity extends AppCompatActivity {
16     private ListView listItem;
17     private ImageView icon ;
18     private TextView title,warning,time;
19 //    1.定义适配器中的数组内容
20     private  int[] icons = {R.drawable.jinggao1,R.drawable.jinggao2,R.drawable.jinggao3};
21     private  String[] titles ={"除湿机通讯失败","温湿度温度高报警","门开"};
22     private  String[] warnings ={"一般报警","次要报警","主要报警"};
23     private  String[] times ={"2021-08-05 09:58:21","2021-08-05 09:58:21","2021-08-05 09:58:21"};
24 
25 
26     @Override
27     protected void onCreate(Bundle savedInstanceState) {
28         super.onCreate(savedInstanceState);
29         setContentView(R.layout.activity_moving);
30         listItem = findViewById(R.id.list_item);
31         MyAdapter md = new MyAdapter();
32         listItem.setAdapter(md);
33     }
34     private class MyAdapter extends BaseAdapter {
35 
36         @Override
37         public int getCount() { // 获取item的数量
38             return titles.length;
39         }
40 
41         @Override
42         public Object getItem(int i) { //记录当前item的序号，从0开始，getItem获取某个item对象
43             return titles[i];
44         }
45 
46         @Override
47         public long getItemId(int i) { //获取到选中的item项的编号
48             return i;
49         }
50 
51         @Override //用于适配listview要加载的内容，包括视图和数据
52         public View getView(int i, View convertView, ViewGroup viewGroup) {
53             // 将item布局文件解析成一个view对象
54 //            View view =View.inflate(MovingActivity.this,R.layout.item_list,null);
55 //            title= view.findViewById(R.id.title);
56 //            warning= view.findViewById(R.id.warning);
57 //            time= view.findViewById(R.id.time);
58 //            icon= view.findViewById(R.id.icon);
59 //
60 //            title.setText(titles[i]);
61 //            warning.setText(warnings[i]);
62 //            time.setText(times[i]);
63 //            icon.setBackgroundResource(icons[i]);
64 
65 //            return view;
66 
67 
68 
69             //优化
70             Object holder =null;
71             // convertView 用于缓存item的对象
72             if(convertView==null){
73                 convertView=View.inflate(MovingActivity.this,R.layout.item_list,null);
74                 holder = new ViewHolder();
75                  ((ViewHolder) holder).title = convertView.findViewById(R.id.title);
76                  ((ViewHolder) holder).warning = convertView.findViewById(R.id.warning);
77                 ((ViewHolder) holder).time = convertView.findViewById(R.id.time);
78                  ((ViewHolder) holder).icon = convertView.findViewById(R.id.icon);
79                 convertView.setTag(holder);
80 
81             }else {
82                 holder = convertView.getTag();
83             }
84             ((ViewHolder) holder).icon.setBackgroundResource(icons[i]);
85             ((ViewHolder) holder).title.setText(titles[i]);
86             ((ViewHolder) holder).warning.setText(warnings[i]);
87             ((ViewHolder) holder).time.setText(times[i]);
88             return convertView;
89         }
90 
91 
92     }
93     static  class ViewHolder{
94         TextView title;
95         TextView time;
96         TextView warning;
97         ImageView icon;
98     }
99 }