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Android Gallery控件使用方法详解
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我们今天给大家讲的就是Gallery控件,这个控件在android当中是非常重要的,我们今天就给大家介绍一下3D的Gallery控件是怎么样来实现的。下面我们就来直接看看代码吧。

1.扩展Gallery:

public class GalleryFlow extends Gallery { private Camera mCamera = new Camera(); // 相机类 private int mMaxRotationAngle = 60; // 最大转动角度 private int mMaxZoom = -300; //// 最大缩放值 private int mCoveflowCenter; // 半径值 public GalleryFlow(Context context) { super (context); // 支持转换 ,执行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 ;} // 控制gallery中每个图片的旋转(重写的gallery中方法) protected boolean getChildStaticTransformation(View child, Transformation t) { // 取得当前子view的半径值 final int childCenter = getCenterOfView(child);System.out.println("childCenter:"+ childCenter); final int childWidth = child.getWidth(); // 旋转角度 int rotationAngle = 0 ; // 重置转换状态 t.clear(); // 设置转换类型 t.setTransformationType(Transformation.TYPE_MATRIX); // 如果图片位于中心位置不需要进行旋转 if (childCenter == mCoveflowCenter) {transformImageBitmap((ImageView) child, t, 0 );} else { // 根据图片在gallery中的位置来计算图片的旋转角度rotationAngle = ( int) ((( float) (mCoveflowCenter - childCenter) / childWidth) * mMaxRotationAngle);System.out.println("rotationAngle:" + rotationAngle); // 如果旋转角度绝对值大于最大旋转角度返回(-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) { // 对效果进行保存 mCamera.save(); final Matrix imageMatrix = t.getMatrix(); // 图片高度 final int imageHeight = child.getLayoutParams().height; // 图片宽度 final int imageWidth = child.getLayoutParams().width; // 返回旋转角度的绝对值 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.Translate(-(imageWidth / 2), -(imageHeight / 2 )); imageMatrix.postTranslate((imageWidth / 2), (imageHeight / 2 )); mCamera.restore(); } }

 2.填充图片容器(BaseAdapter):

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]; } /** * 创建倒影效果 * @return */ public boolean createReflectedImages() { // 倒影图和原图之间的距离 final int reflectionGap = 4 ; int index = 0 ; for ( int imageId : mImageIds) { // 返回原图解码之后的bitmap对象 Bitmap originalImage = BitmapFactory.decodeResource(mContext.getResources(), imageId); int width = originalImage.getWidth(); int height = originalImage.getHeight(); // 创建矩阵对象 Matrix matrix = new Matrix(); // 指定一个角度以0,0为坐标进行旋转 // matrix.setRotate(30); // 指定矩阵(x轴不变,y轴相反) matrix.Scale(1, -1 ); // 将矩阵应用到该原图之中,返回一个宽度不变,高度为原图1/2的倒影位图Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0 ,height/2, width, height/2, matrix, false ); // 创建一个宽度不变,高度为原图+倒影图高度的位图Bitmap bitmapWithReflection = Bitmap.createBitmap(width,(height + height / 2 ), Config.ARGB_8888); // 将上面创建的位图初始化到画布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 ); /** * 参数一:为渐变起初点坐标x位置,* 参数二:为y轴位置,* 参数三和四:分辨对应渐变终点,* 最后参数为平铺方式,* 这里设置为镜像Gradient是基于Shader类,所以我们通过Paint的setShader方法来设置这个渐变 */ LinearGradient shader = new LinearGradient(0,originalImage.getHeight(), 0 ,bitmapWithReflection.getHeight() + reflectionGap,0x70ffffff, 0x00ffffff , TileMode.MIRROR); // 设置阴影 paint.setShader(shader);paint.setXfermode( new PorterDuffXfermode(android.graphics.PorterDuff.Mode.DST_IN)); // 用已经定义好的画笔构建一个矩形阴影渐变效果canvas.drawRect(0, height, width, bitmapWithReflection.getHeight()+ reflectionGap, paint); // 创建一个ImageView用来显示已经画好的bitmapWithReflectionImageView imageView = new ImageView(mContext);imageView.setImageBitmap(bitmapWithReflection); // 设置imageView大小 ,也就是最终显示的图片大小imageView.setLayoutParams( new GalleryFlow.LayoutParams(300, 400 )); // imageView.setScaleType(ScaleType.MATRIX);mImages[index++] = imageView;} return true ;}@SupssWarnings("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.创建Activity:

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(); // 创建倒影效果 GalleryFlow galleryFlow = (GalleryFlow) this .findViewById(R.id.Gallery01); galleryFlow.setFadingEdgeLength(0 ); galleryFlow.setSpacing(-100); // 图片之间的间距 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 ); } }

 

 


原文链接:http://www.cnblogs.com/vus520/archive/2012/04/15/2561982.html
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