AN GridView 横向分页，适合TV等有按键需求的android系统

结果展示：

关键分析：根据屏幕比例算出每一页放多少个Item，然后把每一页的Item push进工作数组中，然后传给adapter，利用adapter的notifyDataSetChanged更新即可；

注意：getCount返回的是工作数组的size，这样的话最后一页才不会出错（往往是抛出空指针）

关键代码：

MainActivity.java

public void onCreate(Bundle savedInstanceState){ 
    	
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.activity_main); 
        gridView = (GridView) findViewById(R.id.gridview); 
        
        initView(); 
        
        InputStream input = getResources().openRawResource(R.drawable.android);
        BitmapDrawable android = new BitmapDrawable(input);
        Bitmap bitmap = android.getBitmap();
        
        for(int i=0;i<30;i++){
        	Picture tmp = new Picture();
        	tmp.setImage(bitmap);
        	tmp.setTitle("Name "+String.valueOf(i));
        	pictureInfo.add(tmp);
        }
        
        cl = new Button.OnClickListener() {
			public void onClick(View v) {
				// TODO Auto-generated method stub
				switch (v.getId()) {
				case R.id.btnLeft:
					leftView();
					break;
				case R.id.btnRight:
					rightView();
					break;
				}
			}
		};
		btnLeft.setOnClickListener(cl);
		btnRight.setOnClickListener(cl);
		checkButton();
		initWorkArray();
        
        
        gridView.setOnItemClickListener(new OnItemClickListener() 
            { 
                public void onItemClick(AdapterView<?> parent, View v, int position, long id) 
                { 
                    Toast.makeText(MainActivity.this, "pic" + (position+1), Toast.LENGTH_SHORT).show(); 
                } 
            }); 
        
    } 
    public void initWorkArray(){
    	workArray = new ArrayList<Picture>();
    	
    	for(int i=0;i<VIEW_COUNT;i++){
    		Picture tmp = new Picture();
    		tmp.setImage(pictureInfo.get(i).getImage());
    		tmp.setTitle(pictureInfo.get(i).getTitle());
    		
    		
    		workArray.add(tmp);
    		
    		
    	}
    	
    	
    	for(int i=0;i<VIEW_COUNT;i++){
    		
    		System.out.print("1-----"+workArray.get(i).getTitle());
    		
    		
    	}
    	adapter = new PictureAdapter( this,workArray); 
        gridView.setAdapter(adapter); 
        
        
    }
    
    public void undateWorkArray(){
    	workArray = new ArrayList<Picture>();
    	
    	int begin=(index-1)*VIEW_COUNT;
    	int end=index*VIEW_COUNT;
    	if(pictureInfo.size()<index * VIEW_COUNT)
    		end=pictureInfo.size();
    	
    	for(int i=begin;i<end;i++){
    		Picture tmp = new Picture();
    		tmp.setImage(pictureInfo.get(i).getImage());
    		tmp.setTitle(pictureInfo.get(i).getTitle());
    		workArray.add(tmp);
    	}
    	adapter.updateMusicInfoBean(workArray);
    	
    }
    public void initView() {
		
		btnLeft = (Button) findViewById(R.id.btnLeft);
		btnRight = (Button) findViewById(R.id.btnRight);
	}
    
    public void leftView() {
		index--;
		undateWorkArray();
		adapter.notifyDataSetChanged();
		checkButton();
	}

	public void rightView() {
		index++;
		undateWorkArray();
		adapter.notifyDataSetChanged();
		checkButton();
	}

	public void checkButton() {
		if(index<=1){
			btnLeft.setEnabled(false);
			System.out.println("----btnLeft.setEnabled(false)---");
		}
			
		else{
			btnLeft.setEnabled(true);
			System.out.println("----btnLeft.setEnabled(true)---");
		}
			
		if(pictureInfo.size()<index * VIEW_COUNT){
			System.out.println("----btnRight.setEnabled(false)---");
			btnRight.setEnabled(false);
		}
			
		else{
			System.out.println("----btnRight.setEnabled(true)---");
			btnRight.setEnabled(true);
		}
	}

adapter的设计

public class PictureAdapter extends BaseAdapter{ 
	private final static String TAG="MainActivity";
	private Context context;//上下文
	private ArrayList<Picture> pictureInfo;//音乐信息集合
    private LayoutInflater inflater; 
    
    public static int printTimes=0;
    public PictureAdapter(Context context,ArrayList<Picture> pictureInfo) 
    { 
        super(); 
        this.context = context;
		this.pictureInfo = pictureInfo;
		//实例化LayoutInflater
		inflater = LayoutInflater.from(context);
    } 
    public void updateMusicInfoBean(ArrayList<Picture> pictureInfo){
		this.pictureInfo = pictureInfo;
	}
    @Override
    public int getCount() 
    { 
        if (null != pictureInfo) 
        { 
            return pictureInfo.size();
        	//return 8;
        } else
        { 
            return 0; 
        } 
    } 
 
    @Override
    public Object getItem(int position) 
    { 
        return pictureInfo.get(position); 
    } 
 
    @Override
    public long getItemId(int position) 
    { 
        return position; 
    } 
 
    @Override
    public View getView(int position, View convertView, ViewGroup parent) 
    { 
        printTimes++;
        System.out.print("the result:----------------------------------------------------------");
        System.out.println(printTimes);
        Log.i(TAG, "the getview is called at "+String.valueOf(printTimes)+" time ");
        
    	ViewHolder viewHolder; 
        if (convertView == null) 
        { 
            convertView = inflater.inflate(R.layout.grid_item, null); 
            viewHolder = new ViewHolder(); 
            viewHolder.title = (TextView) convertView.findViewById(R.id.title); 
            viewHolder.image = (ImageView) convertView.findViewById(R.id.image); 
            convertView.setTag(viewHolder); 
        } else
        { 
            viewHolder = (ViewHolder) convertView.getTag(); 
        }
        
        viewHolder.title.setText(pictureInfo.get(position).getTitle()); 
        viewHolder.image.setImageBitmap(pictureInfo.get(position).getImage()); 
        return convertView; 
    } 
 
} 

picture类

public class Picture 
{ 
    private String title; 
    private Bitmap image; 
 
    public Picture() 
    { 
        super(); 
    } 
 
    public Picture(String title, Bitmap image) 
    { 
        super(); 
        this.title = title; 
        this.image = image; 
    } 
 
    public String getTitle() 
    { 
        return title; 
    } 
 
    public void setTitle(String title) 
    { 
        this.title = title; 
    } 
 
    public Bitmap getImage() 
    { 
        return image; 
    } 
 
    public void setImage(Bitmap image) 
    { 
        this.image = image; 
    } 
} 

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >
        <Button 
            android:layout_height="wrap_content"
            android:layout_width="wrap_content"
            android:id="@+id/btnLeft"
            android:text="lastPage" />
        <Button 
            android:layout_height="wrap_content"
            android:layout_width="wrap_content"
            android:id="@+id/btnRight"
            android:text="nextPage" />
    </LinearLayout>

    <GridView
        android:id="@+id/gridview"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:columnWidth="70dp"
        android:descendantFocusability="blocksDescendants"
        android:gravity="center"
        android:horizontalSpacing="10dp"
        android:listSelector="@drawable/list_selector"
        android:numColumns="auto_fit"
        android:stretchMode="columnWidth"
        android:verticalSpacing="10dp" />

</LinearLayout>

grid_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/root"
    android:orientation="vertical"  
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"  
    android:layout_marginTop="5dp"
    >
    <ImageView  
        android:id="@+id/image"
        android:layout_width="100dp"
        android:layout_height="100dp"  
        android:layout_gravity="center"
        android:scaleType="fitXY"
        android:padding="4dp"
        
        
       />
    <TextView  
        android:id="@+id/title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"  
        android:layout_gravity="center"
        android:gravity="center_horizontal"
        
        />
</LinearLayout>