How to get NSRange(s) for a substring in NSString? [duplicate]

问题

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...";

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];
    }
}

回答1:

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];
    }];

回答2:

with

[str rangeOfString:@"California"]

and

[str rangeOfString:@"California" options:YOUR_OPTIONS range:rangeToSearch]

回答3:

You may use rangeOfString:options:range: or NSScanner (there are other possibilities like regexps but anyway). It's easier to use first approach updating range, i.e. search for first occurrence and then depending on the result update the search range. When the search range is empty, you've found everything;

来源：https://stackoverflow.com/questions/13621245/how-to-get-nsranges-for-a-substring-in-nsstring

标签

ios

nsstring

uitextview

nsattributedstring

nsrange