一：截取后台返回的数据中有 "\r\n”

NSString *string = [NSString stringWithFormat:@"%@",@“guid=这是我要截取到的\r\n"];
        
string = [string stringByReplacingOccurrencesOfString:@"\r\n" withString:@""];

NSLog(@"截取的值为：%@",string);

二：截取IP

NSString *string = @"http://这是我要截取到的IP:8080/news";
        
NSRange range = [string rangeOfString:@"://"]; //现获取要截取的字符串位置
NSString *str = [string substringFromIndex:range.location + range.length]; //截取字符串
if([str rangeOfString:@":"].location !=NSNotFound)
{
            
NSRange rangeTwo = [str rangeOfString:@":"];
            
NSString *result = [str substringToIndex:rangeTwo.location];
            
NSLog(@"%@",result);
            
 }
        
else

        {
            
NSRange rangeTwo = [str rangeOfString:@"/"];
            
            
NSString *result = [str substringToIndex:rangeTwo.location];
            
NSLog(@"%@",result);

        }