如何设置背景的hex颜色代码
可能重复：
我怎样才能从一个hexstring创build一个UIColor？
我想以编程方式设置UIView背景的颜色。
这似乎并不能通过Interfacebuilder来完成。 我应该怎么做，如果我想把它设置为一些hex代码的颜色？
我喜欢使用这一小段代码在我的应用程序中使用HTML Web颜色。
用法：
[self.view setBackgroundColor: [self colorWithHexString:@"FFFFFF"]]; /* white */ 代码：
-(UIColor*)colorWithHexString:(NSString*)hex { NSString *cString = [[hex stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString]; // String should be 6 or 8 characters if ([cString length] < 6) return [UIColor grayColor]; // strip 0X if it appears if ([cString hasPrefix:@"0X"]) cString = [cString substringFromIndex:2]; if ([cString length] != 6) return [UIColor grayColor]; // Separate into r, g, b substrings NSRange range; range.location = 0; range.length = 2; NSString *rString = [cString substringWithRange:range]; range.location = 2; NSString *gString = [cString substringWithRange:range]; range.location = 4; NSString *bString = [cString substringWithRange:range]; // Scan values unsigned int r, g, b; [[NSScanner scannerWithString:rString] scanHexInt:&r]; [[NSScanner scannerWithString:gString] scanHexInt:&g]; [[NSScanner scannerWithString:bString] scanHexInt:&b]; return [UIColor colorWithRed:((float) r / 255.0f) green:((float) g / 255.0f) blue:((float) b / 255.0f) alpha:1.0f]; }
这是UIColor的简单类别，可以帮助您从8位整型值创build颜色
和hex值（“＃a2ffc0”）。
的UIColor + CreateMethods.h
// // UIColor+CreateMethods.h // // Created by Tomasz Rybakiewicz on 1/13/12. // #import <UIKit/UIKit.h> @interface UIColor (CreateMethods) // wrapper for [UIColor colorWithRed:green:blue:alpha:] // values must be in range 0 - 255 + (UIColor*)colorWith8BitRed:(NSInteger)red green:(NSInteger)green blue:(NSInteger)blue alpha:(CGFloat)alpha; // Creates color using hex representation // hex - must be in format: #FF00CC // alpha - must be in range 0.0 - 1.0 + (UIColor*)colorWithHex:(NSString*)hex alpha:(CGFloat)alpha; @end
的UIColor + CreateMethods.m
// // UIColor+CreateMethods.m // // Created by Tomasz Rybakiewicz on 1/13/12. // #import "UIColor+CreateMethods.h" @implementation UIColor (CreateMethods) + (UIColor*)colorWith8BitRed:(NSInteger)red green:(NSInteger)green blue:(NSInteger)blue alpha:(CGFloat)alpha { return [UIColor colorWithRed:(red/255.0) green:(green/255.0) blue:(blue/255.0) alpha:alpha]; } + (UIColor*)colorWithHex:(NSString*)hex alpha:(CGFloat)alpha { assert(7 == [hex length]); assert('#' == [hex characterAtIndex:0]); NSString *redHex = [NSString stringWithFormat:@"0x%@", [hex substringWithRange:NSMakeRange(1, 2)]]; NSString *greenHex = [NSString stringWithFormat:@"0x%@", [hex substringWithRange:NSMakeRange(3, 2)]]; NSString *blueHex = [NSString stringWithFormat:@"0x%@", [hex substringWithRange:NSMakeRange(5, 2)]]; unsigned redInt = 0; NSScanner *rScanner = [NSScanner scannerWithString:redHex]; [rScanner scanHexInt:&redInt]; unsigned greenInt = 0; NSScanner *gScanner = [NSScanner scannerWithString:greenHex]; [gScanner scanHexInt:&greenInt]; unsigned blueInt = 0; NSScanner *bScanner = [NSScanner scannerWithString:blueHex]; [bScanner scanHexInt:&blueInt]; return [UIColor colorWith8BitRed:redInt green:greenInt blue:blueInt alpha:alpha]; } @end
请享用。
UIView的setBackgroundColor方法。 您可以使用UIColor initWithRed:green:blue:alpha从hex创build一个UIColor initWithRed:green:blue:alpha需要浮点数，所以您需要进行位移和math运算以获得适当的组件。 这是我如何pipe理它
