Gallery带阴影和缩放特效

本文主要是介绍Gallery带阴影和缩放特效，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

下面这个是在Z轴缩放的效果，忘记是从哪里下载的了，用法直接在xml文件中直接引用就可以了

public class MyGallery extends Gallery {

private Camera mCamera = new Camera();
    private int mMaxRotationAngle = 60;
    private int mMaxZoom = -120;
    private int mCoveflowCenter;

    public MyGallery (Context context) {
            super(context);
            this.setStaticTransformationsEnabled(true);
    }

    public MyGallery (Context context, AttributeSet attrs) {
            super(context, attrs);
            this.setStaticTransformationsEnabled(true);
    }

    public MyGallery (Context context, AttributeSet attrs, int defStyle) {
            super(context, attrs, defStyle);
            this.setStaticTransformationsEnabled(true);
    }

    public int getMaxRotationAngle() {
            return mMaxRotationAngle;
    }

    public void setMaxRotationAngle(int maxRotationAngle) {
            mMaxRotationAngle = maxRotationAngle;
    }

    public int getMaxZoom() {
            return mMaxZoom;
    }

    public void setMaxZoom(int maxZoom) {
            mMaxZoom = maxZoom;
    }

    private int getCenterOfCoverflow() {
            return (getWidth() - getPaddingLeft() - getPaddingRight()) / 2
                            + getPaddingLeft();
    }

    private static int getCenterOfView(View view) {
            return view.getLeft() + view.getWidth() / 2;
    }

    protected boolean getChildStaticTransformation(View child, Transformation t) {

            final int childCenter = getCenterOfView(child);
            final int childWidth = child.getWidth();
            int rotationAngle = 0;

            t.clear();
            t.setTransformationType(Transformation.TYPE_MATRIX);

            if (childCenter == mCoveflowCenter) {
                    transformImageBitmap((ImageView) child, t, 0);
            } else {
                    rotationAngle = (int) (((float) (mCoveflowCenter - childCenter) / childWidth) * mMaxRotationAngle);
                    if (Math.abs(rotationAngle) > mMaxRotationAngle) {
                            rotationAngle = (rotationAngle < 0) ? -mMaxRotationAngle
                                            : mMaxRotationAngle;
                    }
                    transformImageBitmap((ImageView) child, t, rotationAngle);
            }

            return true;
    }

    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
            mCoveflowCenter = getCenterOfCoverflow();
            super.onSizeChanged(w, h, oldw, oldh);
    }

    private void transformImageBitmap(ImageView child, Transformation t,
                    int rotationAngle) {
            mCamera.save();
            final Matrix imageMatrix = t.getMatrix();
            final int imageHeight = child.getLayoutParams().height;
            final int imageWidth = child.getLayoutParams().width;
            final int rotation = Math.abs(rotationAngle);

            // 在Z轴上正向移动camera的视角，实际效果为放大图片。
            // 如果在Y轴上移动，则图片上下移动；X轴上对应图片左右移动。
            mCamera.translate(0.0f, 0.0f, 100.0f);

            // As the angle of the view gets less, zoom in
            if (rotation < mMaxRotationAngle) {
                    float zoomAmount = (float) (mMaxZoom + (rotation * 1.5));
                    mCamera.translate(0.0f, 0.0f, zoomAmount);
            }

            // 在Y轴上旋转，对应图片竖向向里翻转。
            // 如果在X轴上旋转，则对应图片横向向里翻转。
            mCamera.rotateY(rotationAngle);
            mCamera.getMatrix(imageMatrix);
            imageMatrix.preTranslate(-(imageWidth / 2), -(imageHeight / 2));
            imageMatrix.postTranslate((imageWidth / 2), (imageHeight / 2));
            mCamera.restore();
    }

}

如果想要图片带阴影效果的话，就把适配器设置成下面这样，

public class ImageAdapter extends BaseAdapter {

   int mGalleryItemBackground;
   private Context mContext;
   private Integer[] mImageIds;
   private ImageView[] mImages;

   public ImageAdapter(Context c, Integer[] ImageIds) {
       mContext = c;
       mImageIds = ImageIds;
       mImages = new ImageView[mImageIds.length];
   }

   public boolean createReflectedImages() {
       final int reflectionGap = 4;
       int index = 0;

       for (int imageId : mImageIds) {
           Bitmap originalImage = BitmapFactory.decodeResource(mContext
                   .getResources(), imageId);
           int width = originalImage.getWidth();
           int height = originalImage.getHeight();

           Matrix matrix = new Matrix();
           matrix.preScale(1, -1);

           Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0,
                   height / 2, width, height / 2, matrix, false);

           Bitmap bitmapWithReflection = Bitmap.createBitmap(width,
                   (height + height / 2), Config.ARGB_8888);

           Canvas canvas = new Canvas(bitmapWithReflection);

           canvas.drawBitmap(originalImage, 0, 0, null);

           Paint deafaultPaint = new Paint();
           canvas.drawRect(0, height, width, height + reflectionGap,
                   deafaultPaint);

           canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);

           Paint paint = new Paint();
           LinearGradient shader = new LinearGradient(0, originalImage
                   .getHeight(), 0, bitmapWithReflection.getHeight()
                   + reflectionGap, 0x70ffffff, 0x00ffffff, TileMode.CLAMP);

           paint.setShader(shader);

           paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));

           canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()
                   + reflectionGap, paint);

           ImageView imageView = new ImageView(mContext);
           imageView.setImageBitmap(bitmapWithReflection);
           imageView.setLayoutParams(new GalleryFlow.LayoutParams(180, 240));
//           imageView.setScaleType(ScaleType.MATRIX);
           mImages[index++] = imageView;
       }
       return true;
   }

   private Resources getResources() {
       // TODO Auto-generated method stub
       return null;
   }

   public int getCount() {
       return mImageIds.length;
   }

   public Object getItem(int position) {
       return position;
   }

   public long getItemId(int position) {
       return position;
   }

   public View getView(int position, View convertView, ViewGroup parent) {
       return mImages[position];
   }

   public float getScale(boolean focused, int offset) {
       return Math.max(0, 1.0f / (float) Math.pow(2, Math.abs(offset)));
   }

}