效果图:

基本原理［图来自官方文档］：

当前点［current point］、控制点［control point］和结束点［endPoint］之间的关系定义了实际的曲线。

函数代码实例：

#pragma mark画二次贝塞尔曲线

-(void)secondBeziePathDraw

{

UIBezierPath*path=[UIBezierPathbezierPath];

//起点[左侧]

[pathmoveToPoint:CGPointMake(20,self.frame.size.height-100)];

//二次曲线

[pathaddQuadCurveToPoint:CGPointMake(self.frame.size.width-30,self.frame.size.height-100)controlPoint:CGPointMake(self.frame.size.width/2,self.frame.size.height-10)];

path.lineWidth=8;

UIColor*sColor=[UIColorredColor];

[sColorset];

[pathstroke];

}