Android自定义view实现圆形waveview
时间：2020-10-14 15:00:27 | 栏目：Android代码 | 点击：次
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。
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
@Override
protected 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。