Android GridView的使用方法

Android的GridView控件用于把一系列的空间组织成一个二维的网格显示出来 应用的比较多的就是组合图片显示 下面我就详细讲一个例子

首先写一个类继承BaseAdapter

[java] view plaincopy

1. public class ImageList extends BaseAdapter {  

2.       

3.         public Bitmap[] image;  

4.         Activity activity;  

5.           

6.         // construct  

7.         public ImageList(Activity a) {  

8.             activity = a;  

9.         }  

10.         @Override  

11.         public int getCount() {  

12.             // TODO Auto-generated method stub  

13.             return image.length;  

14.         }  

15.         @Override  

16.         public Object getItem(int position) {  

17.             // TODO Auto-generated method stub  

18.             return image[position];  

19.         }  

20.         @Override  

21.         public long getItemId(int position) {  

22.             // TODO Auto-generated method stub  

23.             return position;  

24.         }  

25.         public View getView(int position, View convertView, ViewGroup parent) {  

26.             // TODO Auto-generated method stub  

27.             ImageView imageView;  

28.             if (convertView == null) {  

29.                 imageView = new ImageView(activity);  

30.                 imageView.setLayoutParams(new GridView.LayoutParams(50, 50));// 设置ImageView宽高  

31.                 imageView.setAdjustViewBounds(false);  

32.                 imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);  

33.                   

34.             } else {  

35.                 imageView = (ImageView) convertView;  

36.             }  

37.             imageView.setImageBitmap(image[position]);  

38.               

39.             return imageView;  

40.         }  

41.         public static Bitmap drawableToBitmap(Drawable drawable) {    

42.                 

43.             Bitmap bitmap = Bitmap    

44.                             .createBitmap(    

45.                                             drawable.getIntrinsicWidth(),    

46.                                             drawable.getIntrinsicHeight(),    

47.                                             drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888    

48.                                                             : Bitmap.Config.RGB_565);    

49.             Canvas canvas = new Canvas(bitmap);    

50.             drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());    

51.             drawable.draw(canvas);    

52.             return bitmap;    

53.     }    

54.     }  

然后在主程序里

[c-sharp] view plaincopy

1. final GridView gv = (GridView) findViewById(R.id.grid);  

2.                 ImageList adapter = new ImageList(available.this);  

3.                 Resources res=getResources();    

4.                 Bitmap bmp=BitmapFactory.decodeResource(res, R.drawable.logo);    

5.                 adapter.image=new Bitmap[20];  

6.                 for(int i=0;i<=19;i++)  

7.                 {  

8.                     adapter.image[i]=bmp;  

9.                 }  

10. gv.setAdapter(adapter);  

11.                 gv.setOnItemClickListener(new OnItemClickListener() {  

12.                     @Override  

13.                     public void onItemClick(AdapterView<?> arg0, View arg1,  

14.                             int arg2, long arg3) {  

15.                         // TODO Auto-generated method stub  

16.                         Log.i("phb", arg2 + "");  

17.                         Log.i("phbsel",gv.isFocused()+"");  

18.                         Intent i=new Intent(available.this, com.mobile.links.shop.mycx.shopcart.class);  

19.                         startActivity(i);  

20.                     }  

21.                 });  

22.                gv.setOnItemSelectedListener(new OnItemSelectedListener(){  

23.                 @Override  

24.                 public void onItemSelected(AdapterView<?> arg0, View arg1,  

25.                         int arg2, long arg3) {  

26.                     // TODO Auto-generated method stub  

27.                     Log.i("selected",arg2+"");  

28.                     tv.setText(arg2+":detail");  

29.                 }  

30.                 @Override  

31.                 public void onNothingSelected(AdapterView<?> arg0) {  

32.                     // TODO Auto-generated method stub  

33.                       

34.                 }  

35.                      

36.                });  

37.                   

其中onClick函数是判断被点击

而onSelect函数是判断被选中 也就是获得焦点的imageview

这样我们就可以基于gridview来做一些应用了。

构建gridview的xml代码

[c-sharp] view plaincopy

1. <?xml version="1.0" encoding="utf-8"?>  

2. <LinearLayout  

3. android:id="@+id/relativelayout"  

4. android:layout_width="fill_parent"  

5. android:layout_height="fill_parent"  

6. xmlns:android="http://schemas.android.com/apk/res/android"  

7. android:orientation="vertical"  

8. >  

9. <GridView android:id="@+id/availgrid"   

10.   android:layout_width="fill_parent"   

11.   android:layout_height="wrap_content"   

12.   android:numColumns="4"   

13.   android:verticalSpacing="30dp"   

14.   android:layout_centerHorizontal = "true"  

15.     

16.   />   

17.    

18.    

19. </LinearLayout>