字符串截取

NSString *string = @"abavavasdsvx,as.dsf/,.[abcdefghijklmn]dgdfg";

NSRange start = [string rangeOfString:@"["];
NSRange end = [string rangeOfString:@"]"];
NSString *sub = [string substringWithRange:NSMakeRange(start.location, end.location-start.location+1)];

NSLog(@"sub=%@",sub);