如何为背景设置十六进制颜色代码 [英] how to set hex color code for background

问题描述

可能重复：

创建一个uicolor-from-a-hex-string>

我想以编程方式设置UIView背景的颜色。

似乎我不能通过Interfacebuilder 。我应该怎么做，如果我想将它设置为一些十六进制代码的颜色？

我喜欢用这个小小的一块代码在我的应用程序中使用HTML Web颜色。

用法：

  [self.view setBackgroundColor：[self colorWithHexString ：@ FFFFFF]]; / *白色* / 
  

代码：

   - （UIColor *）colorWithHexString：（NSString *）hex 
 {
 NSString * cString = [[hex stringByTrimmingCharactersInSet：[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString]; 
 
 //字符串应该是6或8个字符
 if（[cString length] <6）return [UIColor grayColor]; 
 
 //如果它出现
，剥离0X if（[cString hasPrefix：@0X]）cString = [cString substringFromIndex：2]; 
 
 if（[cString length]！= 6）return [UIColor grayColor]; 
 
 //分为r，g，b子串
 NSRange范围; 
 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]; 
 
 //扫描值
 unsigned int r，g，b; 
 [[NSScanner scannerWithString：rString] scanHexInt：& r]; 
 [[NSScanner scannerWithString：gString] scanHexInt：& g]; 
 [[NSScanner scannerWithString：bString] scanHexInt：& b]; 
 $ b return [UIColor colorWithRed :(（float）r / 255.0f）
 green：（（float）g / 255.0f）
 blue：（（float）b / 255.0 f）
 alpha：1.0f]; 
} 
  

Possible Duplicate:
How can I create a UIColor from a hex string?

I want to programmatically set the color of the UIView Background.

It doesn't seem like I can do it through Interfacebuilder. How should I do it if I want to set it to some hex code color?

解决方案

I like to use this little piece of code to use HTML web colors in my apps.

Usage:

[self.view setBackgroundColor: [self colorWithHexString:@"FFFFFF"]]; /* white */

The Code:

-(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];  
} 

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