android中简单的图片翻页效果
参考http://www.blogjava.net/wangxinsh55/archive/2011/09/21/359146.html实现，具体代码如下：
public class PageWidget extends View { private Bitmap foreImage; private Bitmap bgImage; private PointF touchPt; private int screenWidth; private int screenHeight; private GradientDrawable shadowDrawableRL; private GradientDrawable shadowDrawableLR; private ColorMatrixColorFilter mColorMatrixFilter; private Scroller mScroller; private int lastTouchX; public PageWidget(Context context) { super(context); // TODO Auto-generated constructor stub touchPt = new PointF(-1,-1); //ARGB A(0-透明,255-不透明) int[] color = { 0xb0333333 ,0x00333333}; shadowDrawableRL = new GradientDrawable(GradientDrawable.Orientation.RIGHT_LEFT, color); shadowDrawableRL.setGradientType(GradientDrawable.LINEAR_GRADIENT); shadowDrawableLR = new GradientDrawable(GradientDrawable.Orientation.LEFT_RIGHT, color); shadowDrawableLR.setGradientType(GradientDrawable.LINEAR_GRADIENT); float array[] = { 0.55f, 0, 0, 0, 80.0f, 0 ,0.55f, 0, 0, 80.0f, 0 , 0,0.55f, 0, 80.0f, 0 , 0, 0, 0.2f, 0}; ColorMatrix cm = new ColorMatrix(); cm.set(array); /* * |A*0.55 + 80| * |R*0.55 + 80| * |G*0.55 + 80| * |B*0.2| */ // cm.setSaturation(0); mColorMatrixFilter = new ColorMatrixColorFilter(cm); //利用滚动条来实现接触点放开后的动画效果 mScroller = new Scroller(context); } @Override public void computeScroll() { // TODO Auto-generated method stub if (mScroller.computeScrollOffset()) { touchPt.x = mScroller.getCurrX(); touchPt.y = mScroller.getCurrY(); postInvalidate(); } else{ // touchPt.x = -1; // touchPt.y = -1; } super.computeScroll(); } public void SetScreen(int screenWidth,int screenHeight){ this.screenWidth = screenWidth; this.screenHeight = screenHeight; } public Bitmap getForeImage() { return foreImage; } public void setForeImage(Bitmap foreImage) { this.foreImage = foreImage; } public Bitmap getBgImage() { return bgImage; } public void setBgImage(Bitmap bgImage) { this.bgImage = bgImage; } @Override protected void onDraw(Canvas canvas) { // TODO Auto-generated method stub drawPageEffect(canvas); super.onDraw(canvas); } /** * 画前景图片 * @param canvas */ private void drawForceImage(Canvas canvas) { // TODO Auto-generated method stub Paint mPaint = new Paint(); if (foreImage!=null) { canvas.drawBitmap(foreImage, 0, 0, mPaint); } } /** * 画背景图片 * @param canvas */ private void drawBgImage(Canvas canvas,Path path) { // TODO Auto-generated method stub Paint mPaint = new Paint(); if (bgImage!=null) { canvas.save(); //只在与路径相交处画图 canvas.clipPath(path,Op.INTERSECT); canvas.drawBitmap(bgImage, 0, 0, mPaint); canvas.restore(); } } /** * 画翻页效果 * @param canvas */ private void drawPageEffect(Canvas canvas) { // TODO Auto-generated method stub drawForceImage(canvas); Paint mPaint = new Paint(); if (touchPt.x!=-1 && touchPt.y!=-1) { //翻页左侧书边 canvas.drawLine(touchPt.x, 0, touchPt.x,screenHeight, mPaint); //左侧书边画阴影 shadowDrawableRL.setBounds((int)touchPt.x - 20, 0 ,(int)touchPt.x, screenHeight); shadowDrawableRL.draw(canvas); //翻页对折处 float halfCut = touchPt.x + (screenWidth - touchPt.x)/2; canvas.drawLine(halfCut, 0, halfCut, screenHeight, mPaint); //对折处左侧画翻页页图片背面 Rect backArea = new Rect((int)touchPt.x,0,(int)halfCut,screenHeight); Paint backPaint = new Paint(); backPaint.setColor(0xffdacab0); canvas.drawRect(backArea, backPaint); //将翻页图片正面进行处理水平翻转并平移到touchPt.x点 Paint fbPaint = new Paint(); fbPaint.setColorFilter(mColorMatrixFilter); Matrix matrix = new Matrix(); matrix.preScale(-1,1); matrix.postTranslate(foreImage.getWidth() + touchPt.x,0); canvas.save(); canvas.clipRect(backArea); canvas.drawBitmap(foreImage, matrix, fbPaint); canvas.restore(); //对折处画左侧阴影 shadowDrawableRL.setBounds((int)halfCut - 50, 0 ,(int)halfCut, screenHeight); shadowDrawableRL.draw(canvas); Path bgPath = new Path(); //可以显示背景图的区域 bgPath.addRect(new RectF(halfCut,0,screenWidth,screenHeight), Direction.CW); //对折出右侧画背景 drawBgImage(canvas,bgPath); //对折处画右侧阴影 shadowDrawableLR.setBounds((int)halfCut, 0 ,(int)halfCut + 50, screenHeight); shadowDrawableLR.draw(canvas); } } @Override public boolean onTouchEvent(MotionEvent event) { // TODO Auto-generated method stub if (event.getAction() == MotionEvent.ACTION_DOWN) { touchPt.x = event.getX(); touchPt.y = event.getY(); } else if(event.getAction() == MotionEvent.ACTION_MOVE){ lastTouchX = (int)touchPt.x; touchPt.x = event.getX(); touchPt.y = event.getY(); postInvalidate(); } else if(event.getAction() == MotionEvent.ACTION_UP){ int dx,dy; dy = 0; //向右滑动 if (lastTouchX<touchPt.x) { dx = foreImage.getWidth() - (int)touchPt.x + 30; } else{ //向左滑动 dx = -(int)touchPt.x - foreImage.getWidth(); } mScroller.startScroll((int)touchPt.x,(int)touchPt.y,dx,dy,1000); postInvalidate(); } //必须为true，否则无法获取ACTION_MOVE及ACTION_UP事件 return true; } } public class PageActivity extends Activity { protected void onCreate(android.os.Bundle savedInstanceState) { requestWindowFeature(Window.FEATURE_NO_TITLE); PageWidget pageWidget = new PageWidget(this); Display display = getWindowManager().getDefaultDisplay(); int width = display.getWidth(); int height = display.getHeight(); pageWidget.SetScreen(width, height); Bitmap bm1 = BitmapFactory.decodeResource(getResources(), R.drawable.pre7); Bitmap bm2 = BitmapFactory.decodeResource(getResources(), R.drawable.after7); Bitmap foreImage = Bitmap.createScaledBitmap(bm1, width, height,false); Bitmap bgImage = Bitmap.createScaledBitmap(bm2, width, height,false); pageWidget.setBgImage(bgImage); pageWidget.setForeImage(foreImage); setContentView(pageWidget); super.onCreate(savedInstanceState); }; }
