Question

我在我的项目中使用了一个画廊，其中我添加了四个图像，我希望它从右侧和左侧都是无限的。我该如何做到这一点？

Answer 1

主要想法是，在getView方法中，您必须使用

position = position % imagesArray.length;
if (position < 0)
    position = position + imagesArray.length;

imagesArray 是将图像保存在res文件夹中的数组。例如：

public class CircularGallery extends Activity {
/** Called when the activity is first created. */
private Integer[] imagesArray = { R.drawable.picture1, R.drawable.picture2, R.drawable.picture3, R.drawable.picture4, R.drawable.picture5, R.drawable.picture6 , R.drawable.picture7   }; 

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    Gallery g = (Gallery) findViewById(R.id.gallery); 
    g.setAdapter(new ImageAdapter(this)); 

    g.setOnItemClickListener(new OnItemClickListener() { 
        public void onItemClick(AdapterView parent, View v, int position, long id) { 
            if (position >= imagesArray.length) { 
                position = position % imagesArray.length; 
            } 
            Toast.makeText(CircularGallery.this, "" + position, Toast.LENGTH_SHORT).show(); 
        } 
    }); 

}

public class ImageAdapter extends BaseAdapter { 
    int mGalleryItemBackground; 
    private Context mContext; 

    public ImageAdapter(Context c) { 
        mContext = c; 
        TypedArray a = obtainStyledAttributes(R.styleable.Gallery1); 
        mGalleryItemBackground = a.getResourceId(R.styleable.Gallery1_android_galleryItemBackground, 0); 

        a.recycle(); 
    } 

    public int getCount() { 
        return Integer.MAX_VALUE; 
    } 

    public Object getItem(int position) { 
        if (position >= imagesArraylength) { 
            position = position % mImageIds.length; 
        } 
        return position; 
    } 

    public long getItemId(int position) { 
        if (position >= imagesArray.length) { 
            position = position % imagesArray.length; 
        } 
        return position; 
    } 

    public View getView(int position, View convertView, ViewGroup parent) { 
        ImageView i = new ImageView(mContext); 
        if (position >= imagesArray.length) { 
            position = position % imagesArray.length; 
        } 
        i.setImageResource(imagesArray[position]); 
        i.setLayoutParams(new Gallery.LayoutParams(80, 80)); 
        i.setScaleType(ImageView.ScaleType.FIT_XY); 
        i.setBackgroundResource(mGalleryItemBackground); 
        return i; 
    } 

    public int checkPosition(int position) { 
        if (position >= imagesArray.length) { 
            position = position % imagesArray.length; 
        } 
        return position; 
    } 
}}

此外，一些开发人员已经完成了这样的功能，您可以在他们的博客上找到来源

Answer 2

如果要设置右侧显示的图像，只需设置g.setSelection(image)

即可

Answer 3

我的第一个猜测是更改适配器数据，即如果您检测到您处于“右边缘”，则获取第一张图像并将其添加到最后，然后拍摄第二张图像等等......

Android：使画廊无限循环的图像

3 个答案: