在开发的过程中可能会遇到富文本展示,例如:一行文本,前面是题后面是答案,题和答案用不同的颜色字体,但是答案的内容在题总也有,这时候用平常的方法就会展示错误,因为把题中的内容改变了颜色二实际答案却没有改变颜色。需要把相同内容的rang放到数组里然后取最后一个rang就可以了。提供一个获得相同内容的rang的数组。

#pragma mark - 获取某个子字符串在某个总字符串中位置数组
/**
 *  获取某个字符串中子字符串的位置数组
 *
 *  @param totalString 总的字符串
 *  @param subString   子字符串
 *
 *  @return 位置数组
 */
+ (NSMutableArray *)ls_getRangeWithTotalString:(NSString *)totalString SubString:(NSString *)subString {
    
    NSMutableArray *arrayRanges = [NSMutableArray array];
    
    if (subString == nil && [subString isEqualToString:@""]) {
        return nil;
    }
    
    NSRange rang = [totalString rangeOfString:subString];
    
    if (rang.location != NSNotFound && rang.length != 0) {
        
        [arrayRanges addObject:[NSNumber valueWithRange:rang]];
        
        NSRange      rang1 = {0,0};
        NSInteger location = 0;
        NSInteger   length = 0;
        
        for (int i = 0;; i++) {
            
            if (0 == i) {
                
                location = rang.location + rang.length;
                length = totalString.length - rang.location - rang.length;
                rang1 = NSMakeRange(location, length);
            } else {
                
                location = rang1.location + rang1.length;
                length = totalString.length - rang1.location - rang1.length;
                rang1 = NSMakeRange(location, length);
            }
            
            rang1 = [totalString rangeOfString:subString options:NSCaseInsensitiveSearch range:rang1];
            
            if (rang1.location == NSNotFound && rang1.length == 0) {
                
                break;
            } else {
                
                [arrayRanges addObject:[NSNumber valueWithRange:rang1]];
            }
        }
        
        return arrayRanges;
    }
    
    return nil;
}