画线
#import "DrawView.h"
@interface DrawView ()
@property (nonatomic, strong) UIBezierPath *path;
@end
@implementation DrawView
- (UIBezierPath *)path
{
if (_path == nil) {
_path = [UIBezierPath bezierPath];
}
return _path;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
// 获取手指的触摸点
CGPoint curP = [touch locationInView:self];
[self.path moveToPoint:curP];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
// 获取手指的触摸点
CGPoint curP = [touch locationInView:self];
[self.path addLineToPoint:curP];
[self setNeedsDisplay];
}
- (void)drawRect:(CGRect)rect
{
[self.path stroke];
}
// 跟随路径而动画
- (void)startAnim
{
// 图层
CAShapeLayer *layer = [CAShapeLayer layer];
layer.path = self.path.CGPath;
layer.fillColor = [UIColor whiteColor].CGColor;
layer.strokeColor = [UIColor redColor].CGColor;
layer.strokeEnd = 1;
[self.layer addSublayer:layer];
CABasicAnimation *anim = [CABasicAnimation animation];
anim.keyPath = @"strokeEnd";
anim.fromValue = @0;
anim.toValue = @1;
anim.duration = 5;
[layer addAnimation:anim forKey:nil];
// 清空画线
[self.path removeAllPoints];
[self setNeedsDisplay];
}
