iphone - 在 NSString 中查找子字符串的所有位置(不仅仅是第一个)

Question

有一个子串在一个字符串中多次出现。我用的是rangeOfString，但是好像只能找到第一个位置。如何找到子字符串的所有位置？

NSString *subString1 = @"</content>";
NSString *subString2 = @"--\n";
NSRange range1 = [newresults rangeOfString:subString1];
NSRange range2 = [newresults rangeOfString:subString2];
int location1 = range1.location;
int location2 = range2.location;
NSLog(@"%i",location1);
NSLog(@"%i",location2);

Answer 1

您可以使用 rangeOfString:options:range: 并将第三个参数设置为超出第一次出现的范围。例如，您可以这样做:

NSRange searchRange = NSMakeRange(0,string.length);
NSRange foundRange;
while (searchRange.location < string.length) {
    searchRange.length = string.length-searchRange.location;
    foundRange = [string rangeOfString:substring options:0 range:searchRange];
    if (foundRange.location != NSNotFound) {
        // found an occurrence of the substring! do stuff here
        searchRange.location = foundRange.location+foundRange.length;
    } else {
        // no more substring to find
        break;
    }
}