IOS我在ViewController中创建自定义视图。当它滚动时，速度非常慢

我在控制器上放置了一个自定义视图，自定义视图的高度非常高。 然后当我滚动控制器时，速度非常慢

测试环境：IOS5.0+，ipod touch

自定义视图：

 @interface UICommonView : UIView
    //.....
 @end

 @implementation UICommonView
 //.....
 -(void)setBorder:(CGFloat)width color:(UIColor*)color
 {
     self.frameColor = color;
     self.frameWidth = width;
     [self.layer setBorderWidth:width];  
     [self.layer setBorderColor:[color CGColor]];  
 }
 -(void)makeShadow
 {
     self.layer.shadowOpacity = 0.7f;
     self.layer.shadowOffset = CGSizeMake(5.0f,3.0f);
     self.layer.shadowColor =[[UIColor blackColor] CGColor];
 }
 -(void)makeCornerRadius:(CGFloat)_cornerRadius
{
    self.cornerRadius = _cornerRadius;
    [self.layer setMasksToBounds:NO];
    [self.layer setCornerRadius:_cornerRadius];
 }
 @end

控制器：

//contentView is UICommonView  
//scrollView is UIScrollView on controller

-(void)viewDidLoad
{
     [self.contentView makeShadow];
     [self.contentView makeCornerRadius:5.0f];
     [self.contentView setBorder:4.0f color:[UIColor white]];
     // self.contentView.backgroundColor = //......
     [self.contentView setFrame:CGRectMake(0,0,320,1200)];
     [self.scrollView addSubview:contentView];
     scrollerView.contentSize = CGSizeMake(320,1300);
     //add other view
     //I tested, only custom View impact speed
}

---

如何优化它。谢谢

如果给阴影提供一条路径，阴影通常会更有效：

-(void)makeShadow
{
    UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:self.layer.bounds cornerRadius:self.cornerRadius];
    self.layer.shadowPath = path.CGPath; 
    self.layer.shadowOpacity = 0.7f;
    self.layer.shadowOffset = CGSizeMake(5.0f,3.0f);
    self.layer.shadowColor =[[UIColor blackColor] CGColor];
}

但是，因为您同时引用了视图的rect和拐角半径，所以应该在这两个视图中调用

[self-makeShadow]

-（void）makeCornerRadius:（CGFloat）\u cornerRadius

以及内部

-(void)setFrame

这样，无论何时更改帧或角半径，阴影都会相应地更新。这将使您的性能更平稳