初识ImageSwither

imageswitcher继承自viewswitcher，使用ImageSwither只需要两步：

1.为ImageSwither提供一个ViewFactory，该ViewFactory生成的View必须是ImageView.

2.需要切换图片时，只要调用ImageSwither的setImageResource，setImageDrawable，setImageURI方法更换图片即可。

下面是一个gallery，上面是个imageSwither，在gallery里每选择一张图片就会显示到Swither上，并有渐入渐出动画效果。

ImageSwitcher + GridView

 1 import android.app.Activity;
 2 import android.os.Bundle;
 3 import android.view.View;
 4 import android.view.ViewGroup;
 5 import android.widget.AdapterView;
 6 import android.widget.AdapterView.OnItemClickListener;
 7 import android.widget.BaseAdapter;
 8 import android.widget.FrameLayout.LayoutParams;
 9 import android.widget.GridView;
10 import android.widget.ImageSwitcher;
11 import android.widget.ImageView;
12 import android.widget.ViewSwitcher.ViewFactory;
13 
14 public class ImageSwitcherTest extends Activity {
15     private GridView gridView;
16     private ImageSwitcher switcher;
17 
18     private int[] mImage = new int[] { R.drawable.p0, R.drawable.p13,
19             R.drawable.p16, R.drawable.p2, R.drawable.p4, R.drawable.p8 };
20 
21     @Override
22     protected void onCreate(Bundle savedInstanceState) {
23         // TODO Auto-generated method stub
24         super.onCreate(savedInstanceState);
25         setContentView(R.layout.layout_imageswitcher);
26         switcher = (ImageSwitcher) findViewById(R.id.imageSwitcher2);
27 
28         switcher.setFactory(new ViewFactory() {
29 
30             @Override
31             public View makeView() {
32                 // TODO Auto-generated method stub
33 
34                 ImageView imageView = new ImageView(ImageSwitcherTest.this);
35                 imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
36                 /*imageView.setLayoutParams(new ImageSwitcher.LayoutParams(
37                         LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));*/
38                 return imageView;
39             }
40         });
41         
42         ImageAdapter adapter = new ImageAdapter();
43         gridView = (GridView) findViewById(R.id.gridView2);    
44         gridView.setAdapter(adapter);
45         
46         gridView.setOnItemClickListener(new OnItemClickListener() {
47 
48             @Override
49             public void onItemClick(AdapterView<?> parent, View view,
50                     int position, long id) {
51                 // TODO Auto-generated method stub
52                 switcher.setImageResource(mImage[position]);
53             }
54         });
55         
56     }
57 
58     class ImageAdapter extends BaseAdapter {
59 
60         @Override
61         public int getCount() {
62             // TODO Auto-generated method stub
63             return mImage.length;
64         }
65 
66         @Override
67         public Object getItem(int position) {
68             // TODO Auto-generated method stub
69             return mImage[position];
70         }
71 
72         @Override
73         public long getItemId(int position) {
74             // TODO Auto-generated method stub
75             return position;
76         }
77 
78         @Override
79         public View getView(int position, View convertView, ViewGroup parent) {
80             // TODO Auto-generated method stub
81             ImageView imageView = new ImageView(ImageSwitcherTest.this);
82             imageView.setImageResource(mImage[position]);
83             return imageView;
84         }
85 
86     }
87 }

 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     <GridView
 8         android:id="@+id/gridView2"
 9         android:layout_width="match_parent"
10         android:layout_height="254dp"
11         android:numColumns="3"
12         android:horizontalSpacing="pt"
13         android:verticalSpacing="2pt"
14         android:gravity="center"
15          >
16     </GridView>
17 
18     <ImageSwitcher
19         android:id="@+id/imageSwitcher2"
20         android:layout_width="match_parent"
21         android:layout_height="wrap_content"
22         android:layout_weight="0.94"
23         android:layout_gravity="center_horizontal"
24         android:inAnimation="@android:anim/fade_in"
25         android:outAnimation="@android:anim/fade_out" 
26         >
27     </ImageSwitcher>
28 
29 </LinearLayout>