如何在NSString中获取子字符串的NSRange？ [英] How to get NSRange(s) for a substring in NSString?

问题描述

NSString *str = @" My name is Mike, I live in California and I work in Texas. Weather in California is nice but in Texas is too hot...";

如何循环使用此NSString并为每次加利福尼亚事件获取NSRange，我希望NSRange因为我想在NSAttributed字符串中更改它的颜色。

How can I loop through this NSString and get NSRange for each occurrence of "California", I want the NSRange because I would like to change it's color in the NSAttributed string.

 NSRange range = NSMakeRange(0,  _stringLength);
 while(range.location != NSNotFound)
 {
    range = [[attString string] rangeOfString: @"California" options:0 range:range];


    if(range.location != NSNotFound)
    {

        range = NSMakeRange(range.location + range.length,  _stringLength - (range.location + range.length));


        [attString addAttribute:NSForegroundColorAttributeName value:_green range:range];
    }
}

推荐答案

很多解决这个问题的方法 - NSScanner 被提及; rangeOfString：options：range 等。为了完整起见，我将提到 NSRegularExpression 。这也有效：

Lots of ways of solving this problem - NSScanner was mentioned; rangeOfString:options:range etc. For completeness' sake, I'll mention NSRegularExpression. This also works:

    NSMutableAttributedString *mutableString = nil;
    NSString *sampleText = @"I live in California, blah blah blah California.";
    mutableString = [[NSMutableAttributedString alloc] initWithString:sampleText];

    NSString *pattern = @"(California)";
    NSRegularExpression *expression = [NSRegularExpression regularExpressionWithPattern:pattern options:0 error:nil];

    //  enumerate matches
    NSRange range = NSMakeRange(0,[sampleText length]);
    [expression enumerateMatchesInString:sampleText options:0 range:range usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop) {
        NSRange californiaRange = [result rangeAtIndex:0];
        [mutableString addAttribute:NSForegroundColorAttributeName value:[NSColor greenColor] range:californiaRange];
    }];

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