IOS中如何画一条线或者虚线
//画线
UIImageView *p_w_picpathView = [[UIImageViewalloc]initWithFrame:CGRectMake(0, 80, SCREENWIDTH, 20)];
[self.viewaddSubview:p_w_picpathView];
UIGraphicsBeginImageContext(p_w_picpathView.frame.size);
[p_w_picpathView.p_w_picpathdrawInRect:CGRectMake(0, 0, p_w_picpathView1.frame.size.width, p_w_picpathView1.frame.size.height)];
CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
CGFloat ls[] = {
5,5
};
CGContextRef context =UIGraphicsGetCurrentContext();
CGContextSaveGState(context);
CGContextSetLineWidth(context, 0.4);
CGContextSetStrokeColorWithColor(context, [UIColorblackColor].CGColor);
CGContextSetLineDash(context, 0, ls, 2);
CGContextBeginPath(context);
CGContextMoveToPoint(context, 5.0, 20.0);
CGContextAddLineToPoint(context, 310.0, 20.0);
CGContextStrokePath(context);
CGContextRestoreGState(context);
p_w_picpathView.p_w_picpath = UIGraphicsGetImageFromCurrentImageContext();