认识NS_REQUIRES_NIL_TERMINATION

NS_REQUIRES_NIL_TERMINATION是系统中多参数传值的一个宏，用于编译时非nil结尾的检查。

找到了官网上的一个栗子：

#import <Cocoa/Cocoa.h>@interface NSMutableArray (variadicMethodExample)- (void) appendObjects:(id) firstObject, ...; // This method takes a nil-terminated list of objects.@end@implementation NSMutableArray (variadicMethodExample)- (void) appendObjects:(id) firstObject, ...{id eachObject;va_list argumentList;if (firstObject) // The first argument isn't part of the varargs list,  {                                   // so we'll handle it separately.  [self addObject: firstObject];  va_start(argumentList, firstObject); // Start scanning for arguments after firstObject.  while (eachObject = va_arg(argumentList, id)) // As many times as we can get an argument of type "id"      [self addObject: eachObject]; // that isn't nil, add it to self's contents.  va_end(argumentList);  }}@end

感觉还不错呦，自己也可以模仿着写一个的：

ZW_UIKit.h

#import <Foundation/Foundation.h>@interface ZW_UIKit : NSObject+ (NSArray *)getMoreArguments:(NSString *)strs,...NS_REQUIRES_NIL_TERMINATION;@end

ZW_UIKit.m

#import "ZW_UIKit.h"@implementation ZW_UIKit#pragma mark - 获取多参数+ (NSArray *)getMoreArguments:(NSString *)strs,...{    va_list args;    va_start(args, strs);    NSMutableArray *allArray = [NSMutableArray array];    for (NSString *str = strs; str != nil; str = va_arg(args,NSString*)) {        [allArray addObject:str];    }    va_end(args);    return allArray.copy;}@end

调用：

[ZW_UIKit getMoreArguments:@"arg1",@"arg2",@"arg3", nil];