UIColor 进阶

多说，请先看头文件：

#import <Foundation/Foundation.h>#import <CoreGraphics/CoreGraphics.h>#import <CoreImage/CoreImage.h>#import <UIKit/UIKitDefines.h>@class UIImage;UIKIT_CLASS_AVAILABLE(2_0) @interface UIColor : NSObject <NSCoding> {  @private}// Convenience methods for creating autoreleased colors+ (UIColor *)colorWithWhite:(CGFloat)white alpha:(CGFloat)alpha;+ (UIColor *)colorWithHue:(CGFloat)hue saturation:(CGFloat)saturation brightness:(CGFloat)brightness alpha:(CGFloat)alpha;+ (UIColor *)colorWithRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue alpha:(CGFloat)alpha;+ (UIColor *)colorWithCGColor:(CGColorRef)cgColor;+ (UIColor *)colorWithPatternImage:(UIImage *)image;+ (UIColor *)colorWithCIColor:(CIColor *)ciColor __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_5_0);// Initializers for creating non-autoreleased colors- (UIColor *)initWithWhite:(CGFloat)white alpha:(CGFloat)alpha;- (UIColor *)initWithHue:(CGFloat)hue saturation:(CGFloat)saturation brightness:(CGFloat)brightness alpha:(CGFloat)alpha;- (UIColor *)initWithRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue alpha:(CGFloat)alpha;- (UIColor *)initWithCGColor:(CGColorRef)cgColor;- (UIColor *)initWithPatternImage:(UIImage*)image;- (UIColor *)initWithCIColor:(CIColor *)ciColor __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_5_0);// Some convenience methods to create colors.  These colors will be as calibrated as possible.// These colors are cached.+ (UIColor *)blackColor;      // 0.0 white + (UIColor *)darkGrayColor;   // 0.333 white + (UIColor *)lightGrayColor;  // 0.667 white + (UIColor *)whiteColor;      // 1.0 white + (UIColor *)grayColor;       // 0.5 white + (UIColor *)redColor;        // 1.0, 0.0, 0.0 RGB + (UIColor *)greenColor;      // 0.0, 1.0, 0.0 RGB + (UIColor *)blueColor;       // 0.0, 0.0, 1.0 RGB + (UIColor *)cyanColor;       // 0.0, 1.0, 1.0 RGB + (UIColor *)yellowColor;     // 1.0, 1.0, 0.0 RGB + (UIColor *)magentaColor;    // 1.0, 0.0, 1.0 RGB + (UIColor *)orangeColor;     // 1.0, 0.5, 0.0 RGB + (UIColor *)purpleColor;     // 0.5, 0.0, 0.5 RGB + (UIColor *)brownColor;      // 0.6, 0.4, 0.2 RGB + (UIColor *)clearColor;      // 0.0 white, 0.0 alpha // Set the color: Sets the fill and stroke colors in the current drawing context. Should be implemented by subclassers.- (void)set;// Set the fill or stroke colors individually. These should be implemented by subclassers.- (void)setFill;- (void)setStroke;// Convenience methods for getting components.// If the receiver is of a compatible color space, any non-NULL parameters are populated and 'YES' is returned. Otherwise, the parameters are left unchanged and 'NO' is returned.- (BOOL)getWhite:(CGFloat *)white alpha:(CGFloat *)alpha;- (BOOL)getHue:(CGFloat *)hue saturation:(CGFloat *)saturation brightness:(CGFloat *)brightness alpha:(CGFloat *)alpha;- (BOOL)getRed:(CGFloat *)red green:(CGFloat *)green blue:(CGFloat *)blue alpha:(CGFloat *)alpha;// Returns a color in the same color space as the receiver with the specified alpha component.- (UIColor *)colorWithAlphaComponent:(CGFloat)alpha;// Access the underlying CGColor or CIColor.@property(nonatomic,readonly) CGColorRef CGColor;@property(nonatomic,readonly) CIColor   *CIColor;@end@interface CIColor(UIKitAdditions)- (id)initWithColor:(UIColor *)color __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_5_0);@end

有时候美工给的是十六进制的颜色值，所以我写了个方法来进行转化：

//  UIColor+UIColor.h#import <UIKit/UIKit.h>@interface UIColor (UIColor)+ (UIColor *)colorWithHexValue:(NSUInteger)hexValue alpha:(CGFloat)alpha;//eg. self.window.backgroundColor = [UIColor colorWithHexValue:0x123456 alpha:0.8];@end

#import "UIColor+UIColor.h"@implementation UIColor (UIColor)+ (UIColor *)colorWithHexValue:(NSUInteger)hexValue alpha:(CGFloat)alpha{    return [UIColor colorWithRed:((hexValue >> 16) & 0x000000FF)/255.0f                           green:((hexValue >> 8) & 0x000000FF)/255.0f                            blue:((hexValue) & 0x000000FF)/255.0                           alpha:alpha];}@end