在drawRect中绘制UIBesierPath没有效果

Question

UIView drawRect 代码：

- (void)drawRect:(CGRect)rect {

   UIBezierPath *trackPath = [UIBezierPath bezierPath];
[trackPath addQuadCurveToPoint:CGPointMake(10, 30) controlPoint:CGPointMake(0, 0)];
[trackPath stroke];

   }

但是没有绘图出现，怎么办？

Answer 1

在addQuadCurve之前加一个初始化点

[trackPath moveToPoint:somePoint];