Android仿新浪微博ListView效果

╰半橙微兮° 2022-08-08 06:21 301阅读 0赞

# 效果图： #

![Center][]

ListView中单个Item代码：

<?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        
        <ImageView 
            android:id="@+id/img"
            android:layout_height="60dp"
            android:layout_width="60dp"
            android:background="#000"
            android:layout_marginLeft="10dp"
            android:layout_marginTop="10dp"/>
    
        <TextView
            android:id="@+id/name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_toRightOf="@+id/img"
            android:layout_marginLeft="20dp"
            android:layout_marginTop="15dp"
            android:text="NoLoading"
            android:textSize="25sp" />
    
        <TextView
            android:id="@+id/content"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignLeft="@+id/name"
            android:layout_marginRight="10dp"
            android:layout_marginTop="50dp"
            android:text="ContentContentContentContentContentContentContentContentContentContentContentContentContent" />
    
    </RelativeLayout>

**列表的显示需要三个元素：**  
  
1．ListVeiw 用来展示列表的View。  
  
2．适配器 用来把数据映射到ListView上的中介。  
  
3．数据 具体的将被映射的字符串，图片，或者基本组件。  
  
根据列表的适配器类型，列表分为三种，ArrayAdapter，SimpleAdapter和SimpleCursorAdapter

**其中以ArrayAdapter最为简单，只能展示一行字。SimpleAdapter有最好的扩充性，可以自定义出各种效果。**

**SimpleCursorAdapter可以认为是SimpleAdapter对数据库的简单结合，可以方面的把数据库的内容以列表的形式**

**展示出来。**

**MainActivty.java中代码如下：**

public class MyListView extends ListActivity {
     
     
        private List<Map<String, Object>> mData;
         
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            mData = getData();
            MyAdapter adapter = new MyAdapter(this);
            setListAdapter(adapter);
        }
     
        private List<Map<String, Object>> getData() {
            List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
     
            Map<String, Object> map = new HashMap<String, Object>();
            map.put("title", "仰望星空");
            map.put("info", "好看");
            map.put("img", R.drawable.i1);
            list.add(map);
     
     
            return list;
        }

下面是BaseAdapter：

public class MyAdapter extends BaseAdapter{
     
            private LayoutInflater mInflater;
             
             
            public MyAdapter(Context context){
                this.mInflater = LayoutInflater.from(context);
            }
            @Override
            public int getCount() {
                // TODO Auto-generated method stub
                return mData.size();
            }
     
            @Override
            public Object getItem(int arg0) {
                // TODO Auto-generated method stub
                return null;
            }
     
            @Override
            public long getItemId(int arg0) {
                // TODO Auto-generated method stub
                return 0;
            }
     
            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                 
                ViewHolder holder = null;
                if (convertView == null) {
                     
                    holder=new ViewHolder();  
                     
                    convertView = mInflater.inflate(R.layout.vlist2, null);
                    holder.img = (ImageView)convertView.findViewById(R.id.img);
                    holder.title = (TextView)convertView.findViewById(R.id.title);
                    holder.info = (TextView)convertView.findViewById(R.id.info);
                    holder.viewBtn = (Button)convertView.findViewById(R.id.view_btn);
                    convertView.setTag(holder);
                     
                }else {
                     
                    holder = (ViewHolder)convertView.getTag();
                }
                 
                 
                holder.img.setBackgroundResource((Integer)mData.get(position).get("img"));
                holder.title.setText((String)mData.get(position).get("title"));
                holder.info.setText((String)mData.get(position).get("info"));
                 
                holder.viewBtn.setOnClickListener(new View.OnClickListener() {
                     
                    @Override
                    public void onClick(View v) {
                        showInfo();                 
                    }
                });
                 
                 
                return convertView;
            }
             
        }
    public final class ViewHolder{
            public ImageView img;
            public TextView title;
            public TextView info;
            public Button viewBtn;
        }

[Center]: /images/20220805/8760028790e940098fc5e1e38c503630.png