使用NSRange的问题：索引超出范围 [英] Problem using NSRange: Index out of bounds

问题描述

我试图检测我的字符串中的网站网址，然后做一些属性字符串的东西，如粗体等。

我的正则表达式定义为：

  static NSRegularExpression * websiteRegularExpression; 
 static inline NSRegularExpression * WebsiteRegularExpression（）{
 if（！websiteRegularExpression）{
 websiteRegularExpression = [[NSRegularExpression alloc] initWithPattern：@\b（https？| ftp | file）：/ / [ -  A-Z0-9 +& @＃/％？=〜_ |！：，...] * [A-Z0-9 +& @＃/％=〜_ |]
 options：NSRegularExpressionCaseInsensitive 
 error：nil]; 
} 
 
 return websiteRegularExpression; 
} 
  

这里是我枚举的地方：

   - （void）setBodyText 
 {
 __block NSRegularExpression * regexp = nil; 
 bodyLabel.delegate = self; 
 [self.bodyLabel setText：@http://www.google.comafterInheritingLabelAttributesAndConfiguringWithBlock：^ NSAttributedString *（NSMutableAttributedString * mutableAttributedString）{
 
 NSRange stringRange = NSMakeRange（0，[mutableAttributedString长度]）; 
 
 regexp = WebsiteRegularExpression（）; 
 NSRange nameRange = [regexp rangeOfFirstMatchInString：[mutableAttributedString string] options：0 range：stringRange]; 
 UIFont * boldSystemFont = [UIFont boldSystemFontOfSize：18.0]; 
 CTFontRef boldFont = CTFontCreateWithName（（CFStringRef）boldSystemFont.fontName，boldSystemFont.pointSize，NULL）; 
 if（boldFont）{
 [mutableAttributedString addAttribute：（NSString *）kCTFontAttributeName value：（id）boldFont range：nameRange]; 
 CFRelease（boldFont）; 
} 
 
 [mutableAttributedString replaceCharactersInRange：nameRange withString：[[[mutableAttributedString string] substringWithRange：nameRange] uppercaseString]]; 
 return mutableAttributedString; 
}]; 
 
 regexp = WebsiteRegularExpression（）; 
 NSRange linkRange = [regexp rangeOfFirstMatchInString：self.bodyLabel.text options：0 range：NSMakeRange（0，[bodyLabel.text length]）]; 
 [self.bodyLabel addLinkToURL：nil withRange：linkRange]; 
} 
  

我得到错误：

  ***由于未捕获异常NSRangeException而终止应用程序，原因：'***  -  [NSCFString substringWithRange：]：范围或索引超出范围
 
解决方案 
 div> 
在调用 substringWithRange 之前检查 nameRange 的内容。如果您的正则表达式不匹配，则返回 rangeOfFirstMatchInString  
 
 
 {NSNotFound，0} 
 
 
 ​​NSNotFound 定义为 NSIntegerMax ，因此您可以想象为什么此值可能超出范围
 
 $ b 
    >所以要检查 substringWithRange 的结果：
  if（nameRange.location == NSNotFound）
 //不匹配WebsiteRegularExpression（）做别的事
  
 
I am trying to detect website URL's in my string and then doing some attribution string stuff like bolding it etc.


My regex is defined as:
static NSRegularExpression *websiteRegularExpression;
static inline NSRegularExpression * WebsiteRegularExpression() {
    if (!websiteRegularExpression) {
        websiteRegularExpression = [[NSRegularExpression alloc] initWithPattern:@"\b(https?|ftp|file)://[-A-Z0-9+&@#/%?=~_|!:,.;]*[A-Z0-9+&@#/%=~_|]" 
                                                                        options:NSRegularExpressionCaseInsensitive 
                                                                          error:nil];
    }

    return websiteRegularExpression;
}
Here is where I enumerate:
 -(void)setBodyText
    {
        __block NSRegularExpression *regexp = nil;    
        bodyLabel.delegate = self;
        [self.bodyLabel setText:@"http://www.google.com" afterInheritingLabelAttributesAndConfiguringWithBlock:^NSAttributedString *(NSMutableAttributedString *mutableAttributedString) {

            NSRange stringRange = NSMakeRange(0, [mutableAttributedString length]);

            regexp = WebsiteRegularExpression ();
            NSRange nameRange = [regexp rangeOfFirstMatchInString:[mutableAttributedString string] options:0 range:stringRange];
            UIFont *boldSystemFont = [UIFont boldSystemFontOfSize:18.0]; 
            CTFontRef boldFont = CTFontCreateWithName((CFStringRef)boldSystemFont.fontName, boldSystemFont.pointSize, NULL);
            if (boldFont) {
                [mutableAttributedString addAttribute:(NSString *)kCTFontAttributeName value:(id)boldFont range:nameRange];
                CFRelease(boldFont);
            }

            [mutableAttributedString replaceCharactersInRange:nameRange withString:[[[mutableAttributedString string] substringWithRange:nameRange] uppercaseString]];
            return mutableAttributedString;
        }];

        regexp = WebsiteRegularExpression();
        NSRange linkRange = [regexp rangeOfFirstMatchInString:self.bodyLabel.text options:0 range:NSMakeRange(0, [bodyLabel.text length])];
        [self.bodyLabel addLinkToURL:nil withRange:linkRange];
    }
I get the error:
*** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[NSCFString substringWithRange:]: Range or index out of bounds'
How can I resolve?
解决方案
Check the contents of nameRange before you call substringWithRange. If your regular expression doesn't match then the return value for rangeOfFirstMatchInString will be 

  
{NSNotFound, 0}
NSNotFound is defined as NSIntegerMax so you can imagine why this value might be out of range for your mutableAttributedString.

Update for comment

So to check the results of substringWithRange:
if (nameRange.location == NSNotFound)
    // didn't match the WebsiteRegularExpression() do something else


                        
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