Android控制項Gallery3D效果執行個體代碼

貼上代碼：
1.擴充Gallery： 複製代碼 代碼如下:public class GalleryFlow extends Gallery {
private Camera mCamera = new Camera();//相機類
private int mMaxRotationAngle = 60;//最大轉動角度
private int mMaxZoom = -300;////最大縮放值
private int mCoveflowCenter;//半徑值
public GalleryFlow(Context context) {
super(context);
//支援轉換 ,執行getChildStaticTransformation方法
this.setStaticTransformationsEnabled(true);
}
public GalleryFlow(Context context, AttributeSet attrs) {
super(context, attrs);
this.setStaticTransformationsEnabled(true);
}
public GalleryFlow(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) {
System.out.println("view left :"+view.getLeft());
System.out.println("view width :"+view.getWidth());
return view.getLeft() + view.getWidth() / 2;
}

複製代碼 代碼如下://控制gallery中每個圖片的旋轉(重寫的gallery中方法)
protected boolean getChildStaticTransformation(View child, Transformation t) {
//取得當前子view的半徑值
final int childCenter = getCenterOfView(child);
System.out.println("childCenter："+childCenter);
final int childWidth = child.getWidth();
//旋轉角度
int rotationAngle = 0;
//重設轉換狀態
t.clear();
//設定轉換類型
t.setTransformationType(Transformation.TYPE_MATRIX);
//如果圖片位於中心位置不需要進行旋轉
if (childCenter == mCoveflowCenter) {
transformImageBitmap((ImageView) child, t, 0);
} else {
//根據圖片在gallery中的位置來計算圖片的旋轉角度
rotationAngle = (int) (((float) (mCoveflowCenter - childCenter) / childWidth) * mMaxRotationAngle);
System.out.println("rotationAngle:" +rotationAngle);
//如果旋轉角度絕對值大於最大旋轉角度返回（-mMaxRotationAngle或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) {
//對效果進行儲存
mCamera.save();
final Matrix imageMatrix = t.getMatrix();
//圖片高度
final int imageHeight = child.getLayoutParams().height;
//圖片寬度
final int imageWidth = child.getLayoutParams().width;
//返迴旋轉角度的絕對值
final int rotation = Math.abs(rotationAngle);
// 在Z軸上正向移動camera的視角，實際效果為放大圖片。
// 如果在Y軸上移動，則圖片上下移動；X軸上對應圖片左右移動。
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軸上旋轉，對應圖片豎向向裡翻轉。
// 如果在X軸上旋轉，則對應圖片橫向向裡翻轉。
mCamera.rotateY(rotationAngle);
mCamera.getMatrix(imageMatrix);
imageMatrix.preTranslate(-(imageWidth / 2), -(imageHeight / 2));
imageMatrix.postTranslate((imageWidth / 2), (imageHeight / 2));
mCamera.restore();
}
}

2.填充圖片容器(BaseAdapter): 複製代碼 代碼如下: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];
}
/**
* 建立倒影效果
* @return
*/
public boolean createReflectedImages() {
//倒影圖和原圖之間的距離
final int reflectionGap = 4;
int index = 0;
for (int imageId : mImageIds) {
//返回原圖解碼之後的bitmap對象
Bitmap originalImage = BitmapFactory.decodeResource(mContext.getResources(), imageId);
int width = originalImage.getWidth();
int height = originalImage.getHeight();
//建立矩陣對象
Matrix matrix = new Matrix();
//指定一個角度以0,0為座標進行旋轉
// matrix.setRotate(30);
//指定矩陣(x軸不變，y軸相反)
matrix.preScale(1, -1);
//將矩陣應用到該原圖之中，返回一個寬度不變，高度為原圖1/2的倒影位元影像
Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0,
height/2, width, height/2, matrix, false);
//建立一個寬度不變，高度為原圖+倒影圖高度的位元影像
Bitmap bitmapWithReflection = Bitmap.createBitmap(width,
(height + height / 2), Config.ARGB_8888);
//將上面建立的位元影像初始化到畫布
Canvas canvas = new Canvas(bitmapWithReflection);
canvas.drawBitmap(originalImage, 0, 0, null);
Paint deafaultPaint = new Paint();
deafaultPaint.setAntiAlias(false);
// canvas.drawRect(0, height, width, height + reflectionGap,deafaultPaint);
canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);
Paint paint = new Paint();
paint.setAntiAlias(false);
/**
* 參數一:為漸層起初點座標x位置，
* 參數二:為y軸位置，
* 參數三和四:分辨對應漸層終點，
* 最後參數為平鋪方式，
* 這裡設定為鏡像Gradient是基於Shader類，所以我們通過Paint的setShader方法來設定這個漸層
*/
LinearGradient shader = new LinearGradient(0,originalImage.getHeight(), 0,
bitmapWithReflection.getHeight() + reflectionGap,0x70ffffff, 0x00ffffff, TileMode.MIRROR);
//設定陰影
paint.setShader(shader);
paint.setXfermode(new PorterDuffXfermode(android.graphics.PorterDuff.Mode.DST_IN));
//用已經定義好的畫筆構建一個矩形陰影漸層效果
canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()+ reflectionGap, paint);
//建立一個ImageView用來顯示已經畫好的bitmapWithReflection
ImageView imageView = new ImageView(mContext);
imageView.setImageBitmap(bitmapWithReflection);
//設定imageView大小 ，也就是最終顯示的圖片大小
imageView.setLayoutParams(new GalleryFlow.LayoutParams(300, 400));
//imageView.setScaleType(ScaleType.MATRIX);
mImages[index++] = imageView;
}
return true;
}
@SuppressWarnings("unused")
private Resources getResources() {
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)));
}
}

3.建立Activity: 複製代碼 代碼如下:public class Gallery3DActivity extends Activity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.layout_gallery);
Integer[] images = { R.drawable.img0001, R.drawable.img0030,
R.drawable.img0100, R.drawable.img0130, R.drawable.img0200,
R.drawable.img0230, R.drawable.img0330,R.drawable.img0354 };
ImageAdapter adapter = new ImageAdapter(this, images);
adapter.createReflectedImages();//建立倒影效果
GalleryFlow galleryFlow = (GalleryFlow) this.findViewById(R.id.Gallery01);
galleryFlow.setFadingEdgeLength(0);
galleryFlow.setSpacing(-100); //圖片之間的間距
galleryFlow.setAdapter(adapter);
galleryFlow.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
Toast.makeText(getApplicationContext(), String.valueOf(position), Toast.LENGTH_SHORT).show();
}
});
galleryFlow.setSelection(4);
}
}

以上實現代碼裡面我都做了注釋相信大家完全可以看懂。稍微解釋下，在BaseAdapter中主要做了圖片的倒影效果以及建立了對原始圖片和倒影的顯示地區。GalleryFlow中主要做了對圖片的旋轉和縮放操作，根據圖片的螢幕中的位置對其進行旋轉縮放操作。
如下