安卓开发实现画廊效果

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:orientation="vertical" >
 6 
 7 
 8 
 9     <Gallery  
10         android:id="@+id/gallery"  
11         android:spacing="5px"          //设置列表项之间的间距为5像素
12         android:unselectedAlpha="0.5"  //设置未被选中的列表项的透明度
13         android:layout_width="match_parent"  
14         android:layout_height="wrap_content" />
15 
16    
17 </LinearLayout>

 1 package xqx;
 2 
 3 import com.example.xqx_lianxi.R;
 4 
 5 import android.app.Activity;
 6 import android.content.res.TypedArray;
 7 import android.os.Bundle;
 8 import android.view.View;
 9 import android.view.ViewGroup;
10 import android.widget.AdapterView;
11 import android.widget.AdapterView.OnItemClickListener;
12 import android.widget.BaseAdapter;
13 import android.widget.Gallery;
14 import android.widget.ImageView;
15 import android.widget.Toast;
16 
17 public class MainGallery extends Activity{
18      //设置画廊图片
19     private int[] imageId = new int[] { R.drawable.ic_launcher,R.drawable.ic_launcher,R.drawable.ic_launcher,R.drawable.ic_launcher,R.drawable.ic_launcher,R.drawable.ic_launcher};
20     @Override
21     protected void onCreate(Bundle savedInstanceState) {
22         // TODO Auto-generated method stub
23         super.onCreate(savedInstanceState);
24         setContentView(R.layout.main_gallery);
25         //获取Gallery组件
26         Gallery gallery = (Gallery) findViewById(R.id.gallery);
27         BaseAdapter adapter = new BaseAdapter() {       
28                //获取当前选项ID
29                @Override  
30                public long getItemId(int position) {  
31                    return position;  
32                }  
33                //获取当前选项值
34                @Override  
35                public Object getItem(int position) {  
36                    return position;  
37                }  
38                //获取数量
39                @Override  
40                public int getCount() {  
41                    return imageId.length;  
42                }
43                
44             @Override
45             public View getView(int position, View convertView, ViewGroup parent) {  
46                 ImageView imageview;   //声明ImageView的对象  
47                 if (convertView == null) {  
48                     imageview = new ImageView(MainGallery.this); //创建ImageView的对象  
49                     imageview.setScaleType(ImageView.ScaleType.FIT_XY);  //设置缩放方式
50                     imageview.setLayoutParams(new Gallery.LayoutParams(500, 400));  
51                     TypedArray typedArray = obtainStyledAttributes(R.styleable.Gallery);  
52                     imageview.setBackgroundResource(typedArray.getResourceId(  
53                             R.styleable.Gallery_android_galleryItemBackground,  
54                             0));  
55                     imageview.setPadding(5, 0, 5, 0);  //设置imageview的内边距
56                 } 
57                 else 
58                 {  
59                     imageview = (ImageView) convertView;  
60                 }  
61                 imageview.setImageResource(imageId[position]);  
62                 return imageview;  
63             }  
64               
65         };
66            //将适配器与Gallery关联
67            gallery.setAdapter(adapter);  
68            gallery.setSelection(imageId.length / 2); //默认显示的图片的id  
69            //画廊图片的点击事件
70            gallery.setOnItemClickListener(new OnItemClickListener() {  
71                @Override  
72                public void onItemClick(AdapterView<?> parent, View view,  
73                        int position, long id) {
74                
75                    Toast.makeText(MainGallery.this,  
76                            "第" + String.valueOf(position+1) + "张图片被选中",  
77                            Toast.LENGTH_SHORT).show();  
78                }  
79            });  
80     
81 }
82 }

1 <declare-styleable name="Gallery">  
2         <attr name="android:galleryItemBackground" />  
3     </declare-styleable>

 gallery.setSelection(imageId.length / 2); //默认显示的图片的id