android 炫酷特效,Android 特效之炫酷水波纹动画

效果图

示例代码

1.初始化画笔

public WaveView(Context context, AttributeSet attrs) {

super(context, attrs);

mPath = new Path();

mPaint = new Paint();

mPaint.setColor(Color.parseColor("#FF2877DD"));

mPaint.setStyle(Paint.Style.FILL_AND_STROKE);

//随波摇的头像

BitmapFactory.Options options = new BitmapFactory.Options();

options.inSampleSize = 1;

mBitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.love, options);

}

2.绘制水波纹

@Override

protected void onDraw(Canvas canvas) {

super.onDraw(canvas);

mPath.reset();

int halfWaveLen = mItemWaveLength / 2;

mPath.moveTo(-mItemWaveLength + dx, originY);

int i = -mItemWaveLength;

for (; i <= getWidth() + mItemWaveLength; i += mItemWaveLength) {

mPath.rQuadTo(halfWaveLen / 2, -100, halfWaveLen, 0);

mPath.rQuadTo(halfWaveLen / 2, 100, halfWaveLen, 0);

}

mPath.lineTo(getWidth(), getHeight());

mPath.lineTo(0, getHeight());

mPath.close();

canvas.drawPath(mPath, mPaint);

mRegion = new Region();

float left = getWidth() / 2;

Region clip = new Region((int) (left - 0.01), 0, (int) left, getHeight() * 2);

mRegion.setPath(mPath, clip);

Rect bounds = mRegion.getBounds();

canvas.drawBitmap(mBitmap, bounds.left - mBitmap.getWidth() / 2, bounds.top - mBitmap.getHeight(), mPaint);

}

3.开启动画实现平移

public void startAnim() {

animator = ValueAnimator.ofInt(0, mItemWaveLength);

animator.setDuration(2800);

animator.setRepeatCount(ValueAnimator.INFINITE);

animator.setInterpolator(new LinearInterpolator());

animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {

@Override

public void onAnimationUpdate(ValueAnimator animation) {

dx = (int) animation.getAnimatedValue();

postInvalidate();

}

});

animator.start();

}