IOS画线的问题

    很多控件中希望加一条线, 常见横的竖的, 比如在一个页面的header里, cell中, 像tableview那样那样的分割线.

所以我总结了几种方式供大家参考：

   1. 利用CGContext去画, 举个例子：

UIImageView *imageView=[[UIImageView alloc] initWithFrame:self.view.frame];  
    [self.view addSubview:imageView];  
   
    self.view.backgroundColor=[UIColor blueColor];  
   
    UIGraphicsBeginImageContext(imageView.frame.size);  
    [imageView.image drawInRect:CGRectMake(0, 0, imageView.frame.size.width, imageView.frame.size.height)];  
    CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);  
    CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 15.0);  //线宽
    CGContextSetAllowsAntialiasing(UIGraphicsGetCurrentContext(), YES);  
    CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 1.0, 0.0, 0.0, 1.0);  //颜色  
    CGContextBeginPath(UIGraphicsGetCurrentContext());  
    CGContextMoveToPoint(UIGraphicsGetCurrentContext(), 100, 100);  //起点坐标
    CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), 200, 100);   //终点坐标
    CGContextStrokePath(UIGraphicsGetCurrentContext());  
    imageView.image=UIGraphicsGetImageFromCurrentImageContext();  
    UIGraphicsEndImageContext();

2. 利用UIView, 我看到过有同学直接设置UIView宽或高为1来做线条:

UIView *line_view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320.f, 1.f)];
    [line_view setBackgroundColor:[UIColor redColor]];
    [self.view addSubview:line_view];

3. 利用UIImageView:

UIImage *separatorImage = [UIImage imageWithRenderColor:[UIColor redColor] renderSize:CGSizeMake(320.f, 1)];
        UIImageView *topSeparatorView = [[UIImageView alloc] initWithImage:separatorImage];
        topSeparatorView.center = CGPointMake(320.f*0.5, 0.5);
        [self addSubview:topSeparatorView];

上述就是总结的三种横线画法, 当然还有其他很多方式, 有想法的可以留言.