最近学习了贝塞尔曲线的一些知识，刚好项目中需要实现一个圆形进度，然后就将实现的waveView记录一下。需要使用的知识大概有自定义view、贝塞尔曲线、valueAnimator（属性动画）、Xfermode等。

以下为效果图：

废话不多说，直接上代码这里只是一些重要的代码。如果需要demo可以去下载。

下载地址

首先需要自定义view的属性：

<declare-styleable name="custom_wave_view_attr"> <attr name="circle_color" format="color"></attr> //圆的颜色 <attr name="circle_background_color" format="color"></attr> //圆的背景色 <attr name="progress_wave_color" format="color"></attr> //水波纹的颜色 <attr name="progress_text_size" format="dimension"></attr> //字体的大小 <attr name="progress_text_color" format="color"></attr> //字体的颜色</declare-styleable>

第二步自定义CustomWaveView

1、实现构造方法，在构造方法中获取属性值

TypedArray ta = context.obtainStyledAttributes(attrs,R.styleable.custom_wave_view_attr);//圆的颜色circle_color = ta.getColor(R.styleable.custom_wave_view_attr_circle_color,getResources().getColor(android.R.color.black));//圆的背景色circle_bg_color = ta.getColor(R.styleable.custom_wave_view_attr_circle_background_color,getResources().getColor(android.R.color.white));//水波纹颜色wave_color = ta.getColor(R.styleable.custom_wave_view_attr_progress_wave_color,getResources().getColor(android.R.color.holo_blue_dark));//字体的颜色text_color = ta.getColor(R.styleable.custom_wave_view_attr_progress_text_color,getResources().getColor(android.R.color.black));//字体的大小textSize = ta.getDimension(R.styleable.custom_wave_view_attr_progress_text_size,30f);//释放资源ta.recycle();

2、初始化画笔

//初始化背景圆画笔mBgCirclePaint = new Paint();//抗锯齿mBgCirclePaint.setAntiAlias(true);//设置背景圆的背景色mBgCirclePaint.setColor(circle_bg_color);//设置充满mBgCirclePaint.setStyle(Paint.Style.FILL);//初始化水波纹画笔mWavePaint = new Paint();//抗锯齿mWavePaint.setAntiAlias(true);//设置水波纹的背景色mWavePaint.setColor(wave_color);//设置充满mWavePaint.setStyle(Paint.Style.FILL);//使用Xfermode获取重叠部分mWavePaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));

3、绘制贝塞尔曲线。以下为原理图。

/*** 初始化贝塞尔曲线上的点*/private void reset() { startP = new PointF(-width, height); nextP = new PointF(-width/2, height); threeP = new PointF(0, height); fourP = new PointF(width/2, height); endP = new PointF(width, height); controllerP1 = new PointF(-width/4, height); controllerP2 = new PointF(-width * 3/4, height); controllerP3 = new PointF(width/4, height); controllerP4 = new PointF(width * 3/4, height);}

4、在onDraw方法中画贝塞尔曲线和圆

@Overrideprotected void onDraw(Canvas canvas) { super.onDraw(canvas); //在透明画布上画背景圆 mCanvas.drawCircle(width/2, height/2, radius, mBgCirclePaint); //贝塞尔曲线 mPath.reset(); mPath.moveTo(startP.x, startP.y); mPath.quadTo(controllerP1.x, controllerP1.y, nextP.x, nextP.y); mPath.quadTo(controllerP2.x, controllerP2.y, threeP.x, threeP.y); mPath.quadTo(controllerP3.x, controllerP3.y, fourP.x, fourP.y); mPath.quadTo(controllerP4.x, controllerP4.y, endP.x, endP.y); mPath.lineTo(endP.x, height); mPath.lineTo(-width, height); //在透明画布上绘制水波纹 mCanvas.drawPath(mPath,mWavePaint); //将画好的圆绘制在画布上 canvas.drawBitmap(mBitmap, 0, 0, null);}

5、使用动画让贝塞尔曲线动起来

/*** 开始动画 让startP的x点坐标在2S时间内循环移动到0点。* depth---进度* waveRipple----水波纹的振幅*/private void startAnimator() { animator = ValueAnimator.ofFloat(startP.x, 0); animator.setInterpolator(new LinearInterpolator()); animator.setDuration(2000); //重复循环 animator.setRepeatCount(ValueAnimator.INFINITE); animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { startP.x = (Float) animation.getAnimatedValue(); startP = new PointF(startP.x, height - depth); nextP = new PointF(startP.x + width/2, height - depth); threeP = new PointF(nextP.x + width/2, height - depth); fourP = new PointF(threeP.x + width/2, height - depth); endP = new PointF(fourP.x + width/2, height - depth); controllerP1 = new PointF(startP.x + width/4, height - depth + waveRipple); controllerP2 = new PointF(nextP.x + width/4, height - depth - waveRipple); controllerP3 = new PointF(threeP.x + width/4, height - depth + waveRipple); controllerP4 = new PointF(fourP.x + width/4, height - depth - waveRipple); invalidate(); } }); animator.start();}

第三步在XML中使用自定义View

<com.criclewaveview_master.CustomWaveView android:id="@+id/custom_circle_wave_view" android:layout_width="wrap_content" android:layout_height="wrap_content" wave:circle_color = "@color/circle_color" android:layout_centerInParent="true" wave:circle_background_color = "@color/circle_bg_color" wave:progress_wave_color = "@color/colorAccent" wave:progress_text_size = "20sp" wave:progress_text_color = "@color/circle_color"/>

这样就完成了自定义WaveView。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。