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Android实现刮刮乐效果

首先要做一个类似橡皮擦的东西吧,然后才能把纸上的笔迹擦除

    /**
     * FileName: SplashActivity.java
     *
     * @desc 橡皮擦功能,类似刮刮乐效果
     * @author HTP
     * @Date 20140311
     * @version 1.00
     */
    public class Text_Rubbler extends TextView {
        private float TOUCH_TOLERANCE; // 填充距离,使线条更自然,柔和,值越小,越柔和。
        // private final int bgColor;
        // 位图
        private Bitmap mBitmap;
        // 画布
        private Canvas mCanvas;
        // 画笔
        private Paint mPaint;
        private Path mPath;
        private float mX, mY;
        private boolean isDraw = false;
        public Text_Rubbler(Context context) {
            /**
             * @param context 上下文
             */
            super(context);
        }
        public Text_Rubbler(Context context, AttributeSet attrs, int defStyle) {
            super(context, attrs, defStyle);
            // bgColor =
            // attrs.getAttributeIntValue("http://schemas.android.com/apk/res/android",
            // "textColor", 0xFFFFFF);
            // System.out.println("Color:"+bgColor);
        }
        public Text_Rubbler(Context context, AttributeSet attrs) {
            super(context, attrs);
            // bgColor =
            // attrs.getAttributeIntValue("http://schemas.android.com/apk/res/android",
            // "textColor", 0xFFFFFF);
            // System.out.println(bgColor);
            // System.out.println(attrs.getAttributeValue("http://schemas.android.com/apk/res/android",
            // "layout_width"));
        }
        @Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
            if (isDraw) {
                mCanvas.drawPath(mPath, mPaint);
                // mCanvas.drawPoint(mX, mY, mPaint);
                canvas.drawBitmap(mBitmap, 0, 0, null);
            }
        }
        /**
         * 开启檫除功能
         *
         * @param bgColor
         *            覆盖的背景颜色
         * @param paintStrokeWidth
         *            触点(橡皮)宽度
         * @param touchTolerance
         *            填充距离,值越小,越柔和。
         */
        public void beginRubbler(final int bgColor, final int paintStrokeWidth,
                float touchTolerance) {
            TOUCH_TOLERANCE = touchTolerance;
            // 设置画笔
            mPaint = new Paint();
            // mPaint.setAlpha(0);
            // 画笔划过的痕迹就变成透明色了
            mPaint.setColor(Color.BLACK); // 此处不能为透明色
            mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
            // 或者
            // mPaint.setAlpha(0);
            // mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
            mPaint.setAntiAlias(true);
            mPaint.setDither(true);
            mPaint.setStyle(Paint.Style.STROKE);
            mPaint.setStrokeJoin(Paint.Join.ROUND); // 前圆角
            mPaint.setStrokeCap(Paint.Cap.ROUND); // 后圆角
            mPaint.setStrokeWidth(paintStrokeWidth); // 笔宽
            // 痕迹
            mPath = new Path();
            ;
            // 覆盖
            // if (getLayoutParams().width == LayoutParams.FILL_PARENT) {
            //
            // }
            mBitmap = Bitmap.createBitmap(getLayoutParams().width,
                    getLayoutParams().height, Config.ARGB_8888);
            mCanvas = new Canvas(mBitmap);
            mCanvas.drawColor(bgColor);
            isDraw = true;
        }
        @Override
        public boolean onTouchEvent(MotionEvent event) {
            if (!isDraw) {
                return true;
            }
            switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN: // 触点按下
                // touchDown(event.getRawX(),event.getRawY());
                touchDown(event.getX(), event.getY());
                invalidate();
                break;
            case MotionEvent.ACTION_MOVE: // 触点移动
                touchMove(event.getX(), event.getY());
                invalidate();
                break;
            case MotionEvent.ACTION_UP: // 触点弹起
                touchUp(event.getX(), event.getY());
                invalidate();
                break;
            default:
                break;
            }
            return true;
        }
        private void touchDown(float x, float y) {
            mPath.reset();
            mPath.moveTo(x, y);
            mX = x;
            mY = y;
        }
        private void touchMove(float x, float y) {
            float dx = Math.abs(x - mX);
            float dy = Math.abs(y - mY);
            if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
                mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
                mX = x;
                mY = y;
            }
        }
        private void touchUp(float x, float y) {
            mPath.lineTo(x, y);
            mCanvas.drawPath(mPath, mPaint);
            mPath.reset();
        }
    }

接下来就是使用橡皮檫擦除了

    /**
     * FileName: RubblerAct.java
     * @Desc    该类通过调用Text_Rubbler这个类将在Activity上显示一片刮一刮的区域,可以出发触摸事件
     * @author  HTP
     * @Date    20140312
     * @version 1.00
     */
    public class RubblerAct extends Activity {
        // 刮开后文字显示
        private TextView tv_rubbler;
        // 得到刮一刮的内容
        private Sentence mSentence;
        // 下一张
        private TextView tv_next;
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            // setContentView(new Rubble(this,"谢谢惠顾",new Rect(100, 200,
            // 300,250),2,1f,14));
            // /////////////////////////////////////////
            setContentView(R.layout.rubbler);
            // 设置的颜色必须要有透明度。
            ((Text_Rubbler) findViewById(R.id.rubbler)).beginRubbler(0xFFFFFFFF, 20,
                    1f);// 设置橡皮擦的宽度等
            mSentence = new Sentence();
            // 随机初始化文字
            tv_rubbler = (TextView) findViewById(R.id.rubbler);
            String str = mSentence.getSentence();
            tv_rubbler.setText(str);
            tv_next = (TextView) findViewById(R.id.tv_next);
            // 点击下一步
            tv_next.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub
                    String str = mSentence.getSentence();
                    tv_rubbler.setText(str);
                    ((Text_Rubbler) findViewById(R.id.rubbler))// 初始化状态
                            .beginRubbler(0xFFFFFFFF, 20, 1f);
                }
            });
        }
        class Rubble extends View {
            private final int PAINT_STROKE_WIDTH;
            private final float TOUCH_TOLERANCE; // 填充距离,使线条更自然,柔和,值越小,越柔和。
            private final int TEXT_SIZE;
            private Bitmap mBitmap;
            // 画布
            private Canvas mCanvas;
            // 画笔
            private Paint mPaint;
            private Path mPath;
            private float mX, mY;
            private final int X, Y, W, H;
            private final Rect touchRect;
            public Rubble(Context context, String bgText, Rect rect,
                    int paintStrokeWidth, float touchTolerance, int textSize) {
                super(context);
                setFocusable(true);
                touchRect = rect;
                W = rect.right - rect.left;
                H = rect.bottom - rect.top;
                X = rect.left;
                Y = rect.top;
                TEXT_SIZE = textSize;
                PAINT_STROKE_WIDTH = paintStrokeWidth;
                TOUCH_TOLERANCE = touchTolerance;
                setBackground(touchRect, bgText);
                initDrowTools();
            }
            private void setBackground(Rect rect, String bgText) {
                DisplayMetrics dm = new DisplayMetrics();
                dm = this.getResources().getDisplayMetrics();
                Bitmap bitmap = Bitmap.createBitmap(dm.widthPixels,
                        dm.heightPixels, Config.ARGB_8888);
                Canvas canvas = new Canvas(bitmap);
                Paint paint = new Paint();
                paint.setColor(0x88000000);
                // paint.setStyle(Style.STROKE);
                // paint.setTextAlign(Align.CENTER);
                paint.setTextSize(TEXT_SIZE);
                // paint.setTextScaleX(1.5f);
                canvas.drawColor(Color.WHITE);
                // 画字的坐标不好控制
                int x = rect.left
                        + (rect.right - rect.left - bgText.length() * TEXT_SIZE)
                        / 2;
                int y = rect.top + (rect.bottom - rect.top - TEXT_SIZE) / 2;
                // int y = 218+25;
                canvas.drawText(bgText, x, y, paint);
                Drawable drawable = new BitmapDrawable(bitmap);
                setBackgroundDrawable(drawable);
            }
            private void initDrowTools() {
                // 设置画笔
                mPaint = new Paint();
                // mPaint.setAlpha(0);
                // 画笔划过的痕迹就变成透明色了
                mPaint.setColor(Color.BLACK); // 此处不能为透明色
                mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
                // 或者
                // mPaint.setAlpha(0);
                // mPaint.setXfermode(new
                // PorterDuffXfermode(PorterDuff.Mode.DST_IN));
                mPaint.setAntiAlias(true);
                mPaint.setDither(true);
                mPaint.setStyle(Paint.Style.STROKE);
                mPaint.setStrokeJoin(Paint.Join.ROUND); // 前圆角
                mPaint.setStrokeCap(Paint.Cap.ROUND); // 后圆角
                mPaint.setStrokeWidth(PAINT_STROKE_WIDTH); // 笔宽
                // 痕迹
                mPath = new Path();
                ;
                // 覆盖
                mBitmap = Bitmap.createBitmap(W, H, Config.ARGB_8888);
                mCanvas = new Canvas(mBitmap);
                mCanvas.drawColor(0x88000000);
            }
            @Override
            protected void onDraw(Canvas canvas) {
                super.onDraw(canvas);
                mCanvas.drawPath(mPath, mPaint);
                // mCanvas.drawPoint(mX, mY, mPaint);
                canvas.drawBitmap(mBitmap, X, Y, null);
            }
            @Override
            public boolean onTouchEvent(MotionEvent event) {
                System.out.print("X--" + event.getX());
                System.out.println("Y--" + event.getY());
                if (!touchRect.contains((int) event.getX(), (int) event.getY())) {
                    return false;
                }
                switch (event.getAction()) {
                // 触点按下
                case MotionEvent.ACTION_DOWN: {
                    touchDown(event.getRawX(), event.getRawY());
                    touchDown(event.getX() - touchRect.left, event.getY()
                            - touchRect.top);
                    invalidate();
                    break;
                }
                case MotionEvent.ACTION_MOVE: // 触点移动
                    touchMove(event.getX() - touchRect.left, event.getY()
                            - touchRect.top);
                    invalidate();
                    break;
                case MotionEvent.ACTION_UP: // 触点弹起
                    touchUp(event.getX() - touchRect.left, event.getY()
                            - touchRect.top);
                    invalidate();
                    break;
                default:
                    break;
                }
                return true;
            }
            private void touchDown(float x, float y) {
                mPath.reset();
                mPath.moveTo(x, y);
                mX = x;
                mY = y;
            }
            private void touchMove(float x, float y) {
                float dx = Math.abs(x - mX);
                float dy = Math.abs(y - mY);
                if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
                    mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
                    mX = x;
                    mY = y;
                }
            }
            private void touchUp(float x, float y) {
                mPath.lineTo(x, y);
                mCanvas.drawPath(mPath, mPaint);
                mPath.reset();
            }
        }
        /**
         * 键盘事件,当按下back键的时候询问是否再按一次退出程序
         */
        // 退出时间
        private long exitTime = 0;
        @Override
        public boolean onKeyDown(int keyCode, KeyEvent event) {
            if (keyCode == KeyEvent.KEYCODE_BACK
                    && event.getAction() == KeyEvent.ACTION_DOWN) {
                if ((System.currentTimeMillis() - exitTime) > 2000) {
                    Toast.makeText(getApplicationContext(), "再按一次退出程序",
                            Toast.LENGTH_SHORT).show();
                    exitTime = System.currentTimeMillis();
                } else {
                    finish();
                    System.exit(0);
                }
                return true;
            }
            return super.onKeyDown(keyCode, event);
        }
    }

 

实现效果如下:

Android实现刮刮乐效果

来自:http://blog.csdn.net/qq544529563/article/details/38795401

天边的星星