如何將角點半徑應用到UIView中沒有問題？

Question

目前，我在滾動視圖中將多個UIView的角落半徑和陰影應用於多個UIView。我注意到，添加角落半徑和陰影會使scrollview每當我滾動時就像瘋狂一樣滯後。我如何應用這些影響而不會讓我的表現受到影響？

Answer 1

嘗試也設置層的shadowPath：

view.layer.cornerRadius=6.0f; 
view.layer.borderWidth=2.0f; 
view.layer.borderColor=[UIColor grayColor].CGColor; 
view.layer.shadowColor = [UIColor blackColor].CGColor; 
view.layer.shadowOpacity = 0.3f; 
view.layer.shadowOffset = CGSizeMake(0, 0.0f); 
view.layer.masksToBounds = NO; 
UIBezierPath *path = [UIBezierPath bezierPathWithRect:view.bounds]; 
view.layer.shadowPath = path.CGPath; 

Answer 2

+(UIImage *)makeRoundCornerImage : (UIImage*) img : (int) cornerWidth : (int) cornerHeight 
{ 
    UIImage * newImage = nil; 

    if(nil != img) 
    { 
     NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; 
     int w = img.size.width; 
     int h = img.size.height; 

     CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); 
     CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst); 

     CGContextBeginPath(context); 
     CGRect rect = CGRectMake(0, 0, img.size.width, img.size.height); 
     addRoundedRectToPath(context, rect, cornerWidth, cornerHeight); 
     CGContextClosePath(context); 
     CGContextClip(context); 

     CGContextDrawImage(context, CGRectMake(0, 0, w, h), img.CGImage); 

     CGImageRef imageMasked = CGBitmapContextCreateImage(context); 
     CGContextRelease(context); 
     CGColorSpaceRelease(colorSpace); 
     [img release]; 


     newImage = [[UIImage imageWithCGImage:imageMasked] retain]; 
     CGImageRelease(imageMasked); 

     [pool release]; 
    } 

    return newImage; 
} 

用這種方法的幫助下，我們可以創建任何PNG文件

UIImage *imageFromFile = [UIImage imageNamed:@"FilterFields.png"]; 
     imageFromFile = [ImageManipulator 
makeRoundCornerImage:imageFromFile : 10 : 10]; 


     [SmallTable setImage:imageFromFile];