如何将变量参数传递给另一个方法？ [英] how to pass variable arguments to another method?

问题描述

我用Google搜索并了解了如何使用变量参数。但我想将我的变量参数传递给另一个方法。我得到错误。怎么做？

i have googled and came to know that how to use the variable arguments. but i want to pass my variable arguments to another method. i m getting errors. how to do that ?

-(void) aMethod:(NSString *) a, ... {
  [self anotherMethod:a]; 
  // i m doing this but getting error. how to pass complete vararg to anotherMethod
}

推荐答案

AFAIK ObjectiveC（就像C和C ++一样）没有为您提供允许您直接考虑的语法。

AFAIK ObjectiveC (just like C and C++) do not provide you with a syntax that allows what you directly have in mind.

通常的解决方法是创建两个版本的一个功能。一个可以直接使用...和另一个调用的函数以va_list的形式传递参数。

The usual workaround is to create two versions of a function. One that may be called directly using ... and another one called by others functions passing the parameters in form of a va_list.

..
[obj aMethod:@"test this %d parameter", 1337);
[obj anotherMethod:@"test that %d parameter", 666);
..

-(void) aMethod:(NSString *)a, ... 
{
    va_list ap;
    va_start(ap, a);

    [self anotherMethod:a withParameters:ap]; 

    va_end(ap);
}

-(void) anotherMethod:(NSString *)a, ...
{
    va_list ap;
    va_start(ap, a);

    [self anotherMethod:a withParameters:ap]; 

    va_end(ap);
}

-(void) anotherMethod:(NSString *)a withParameters:(va_list)valist 
{
    NSLog([[[NSString alloc] initWithFormat:a arguments:valist] autorelease]);
}

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