图形与动画在Android中的实现
public class MyView extends View{ Bitmap myBitmap; Paint paint; public MyView(Context context, AttributeSet attrs) { super(context, attrs); this.initBitmap(); } public void initBitmap(){ paint = new Paint(); myBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.img); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); paint.setAntiAlias(true); paint.setColor(Color.WHITE); paint.setTextSize(15); canvas.drawBitmap(myBitmap, 10, 10, paint); //Saves the current matrix and clip onto a private stack. //Subsequent calls to translate,scale,rotate,skew,concat or clipRect,clipPath //will all operate as usual, but when the balancing call to restore() is made, //those calls will be forgotten, and the settings that existed before the save() will be reinstated(恢复). //Returns: //The value to pass to restoreToCount() to balance this save() int i = canvas.save(); System.out.println("current count -- > " + i); Matrix m1 = new Matrix(); m1.setTranslate(500, 10); Matrix m2 = new Matrix(); m2.setRotate(15); Matrix m3 = new Matrix(); m3.setConcat(m1, m2); m1.setScale(0.8f, 0.8f); m2.setConcat(m3, m1); canvas.drawBitmap(myBitmap, m2, paint); //This call balances a previous call to save(), and is used to //remove all modifications to the matrix/clip state since the last save call. //It is an error to call restore() more times than save() was called. canvas.restore(); int j = canvas.save(); System.out.println("current count -- > " + j); paint.setAlpha(180); m1.setTranslate(200, 100); m2.setScale(1.3f, 1.3f); m2.setConcat(m1, m2); canvas.drawBitmap(myBitmap, m3, paint); //Restores the paint to its default settings. paint.reset(); canvas.restore(); paint.setTextSize(40); paint.setColor(Color.BLUE); canvas.drawText("图片的宽度:" + myBitmap.getWidth(), 150, 220, paint); canvas.drawText("图片的高度:" + myBitmap.getHeight(), 150, 300, paint); paint.reset(); } }
效果图:
posted on 2014-05-11 20:01 leihupqrst 阅读(225) 评论(0) 编辑 收藏 举报