//UIColor 轉 UIImage 
- (UIImage*) createImageWithColor: (UIColor*) color  
    {  
        CGRect rect=CGRectMake(0,0, 1, 1);  
        UIGraphicsBeginImageContext(rect.size);  
        CGContextRef context = UIGraphicsGetCurrentContext();  
        CGContextSetFillColorWithColor(context, [color CGColor]);  
        CGContextFillRect(context, rect);  
        UIImage *theImage = UIGraphicsGetImageFromCurrentImageContext();  
        UIGraphicsEndImageContext();  
        return theImage;  
    } 


//UIImage轉UIColor
[UIColor colorWithPatternImage:[UIImageimageNamed:@“bg.png"]]