在工程中需要从 protocol://customProtocol|title=this is title|message=this is message|shareUrl=this is url 字符串中分别拿到 title、message、shareUrl 的内容，因为字符串的格式是固定的，自然而然的想到了正则表达式, 当然也可以对字符串按照 | 分隔，然后再按 = 分隔之后获取指定的值。
最终实现代码：
NSString *testStr = @"protocol://customProtocol|title=this is title|message=this is message|shareUrl=this is url";
NSString *parten = @"\\|title=(.*?)\\|message=(.*?)\\|shareUrl=(.*)$";
NSError *error = nil;
NSRegularExpression *reg = [NSRegularExpression regularExpressionWithPattern:parten options:NSRegularExpressionCaseInsensitive error:&error]; //options 根据自己需求选择
NSArray *matches = [reg matchesInString:testStr options:NSMatchingReportCompletion range:NSMakeRange(0, testStr.length)];
for (NSTextCheckingResult *match in matches) {
//NSRange matchRange = [match range]; //获取所匹配的最长字符串
for (int i = 0; i < match.numberOfRanges; i++) {
NSRange matchRange = [match rangeAtIndex:i];
NSString *matchString = [testStr substringWithRange:matchRange];
NSLog(@"index:%@, %@", @(i) matchString);
}
}
output:
index:0, |title=this is title|message=this is message|shareUrl=this is url
index:1, this is title
index:2, this is message
index:3, this is url
实际开发过程中遇到的坑：
-
|在正则表达式中是元字符，所以在写parten 中需要用\转义字符, 但在OC中\也是转义字符，所以最后需要\\|来表示匹配|。 - 正则默认是贪心的，所以需要在
.*后加上?正则表达式re中的贪心算法和非贪心算法 - 注意
NSTextCheckingResult的numberOfRanges的用法。rangeAtIndex为0 是匹配最长的结果。
A result must have at least one range, but may optionally have more (for example, to represent regular expression capture groups). The range at index 0 always matches the range property. Additional ranges, if any, will have indexes from 1 to numberOfRanges-1. rangeWithName: can be used with named regular expression capture groups.
最后推荐一个比较友好的正则表达式在线测试网站Oneline regex test
