WaveView

简单地波纹效果

##一个类轻松搞定波浪 public class WaveView extends View { private static final int WAVE_PAINT_COLOR = 0xffffffff; private static final int WAVE_PAINT_COLOR1 = 0xccDCFCFC;

private Path mAbovePath, mBelowWavePath;
private Paint mAboveWavePaint, mBelowWavePaint;

private DrawFilter mDrawFilter;

private float φ;

private OnWaveAnimationListener mWaveAnimationListener;

public WaveView(Context context, AttributeSet attrs) {
    super(context, attrs);
    // 初始化路径
    mAbovePath = new Path();
    mBelowWavePath = new Path();
    // 初始化画笔
    mAboveWavePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    mAboveWavePaint.setAntiAlias(true);
    mAboveWavePaint.setStyle(Paint.Style.FILL);
    mAboveWavePaint.setColor(WAVE_PAINT_COLOR);

    mBelowWavePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    mBelowWavePaint.setAntiAlias(true);
    mBelowWavePaint.setStyle(Paint.Style.FILL);
    mBelowWavePaint.setColor(Color.argb(0,0,0,255));
    mBelowWavePaint.setAlpha(80);
    // 画布抗锯齿
    mDrawFilter = new PaintFlagsDrawFilter(0, Paint.ANTI_ALIAS_FLAG
            | Paint.FILTER_BITMAP_FLAG);
}

@Override
protected void onDraw(Canvas canvas) {

    canvas.setDrawFilter(mDrawFilter);

    mAbovePath.reset();
    mBelowWavePath.reset();

    φ -= 0.1f;

    float y, y2;

    double ω = 2 * Math.PI / getWidth();

    mAbovePath.moveTo(getLeft(), getBottom());
    mBelowWavePath.moveTo(getLeft(), getBottom());
    for (float x = 0; x <= getWidth(); x += 20) {
        /**
         * y=Asin(ωx+φ)+k A—振幅越大，波形在y轴上最大与最小值的差值越大 ω—角速度， 控制正弦周期(单位角度内震动的次数)
         * φ—初相，反映在坐标系上则为图像的左右移动。这里通过不断改变φ,达到波浪移动效果 k—偏距，反映在坐标系上则为图像的上移或下移。
         */
        y = (float) (30 * Math.cos(ω * x + φ + 8) + 80);
        y2 = (float) (30 * Math.sin(ω * x + φ) + 80);
        mAbovePath.lineTo(x, y);
        mBelowWavePath.lineTo(x, y2);

// Log.w("lbk", "x:" + x + "," + "y:" + y2); // 回调 把y坐标的值传出去(在activity里面接收让小机器人随波浪一起摇摆) mWaveAnimationListener.OnWaveAnimation(y); } mAbovePath.lineTo(getRight(), getBottom()); mBelowWavePath.lineTo(getRight(), getBottom());

    canvas.drawPath(mAbovePath, mAboveWavePaint);
    canvas.drawPath(mBelowWavePath, mBelowWavePaint);

    postInvalidateDelayed(20);

}

public void setOnWaveAnimationListener(OnWaveAnimationListener l) {
    this.mWaveAnimationListener = l;
}

public interface OnWaveAnimationListener {
    void OnWaveAnimation(float y);
}

}