从 Swift 调用可变参数 Objective-C 函数 [英] Call variadic Objective-C function from Swift

问题描述

我已经总结了问题的步骤，我在Objective-C中定义了一个C函数:

I have summarized the steps of the problem, I have a C function defined in Objective-C:

ObjC.h

#import <Foundation/Foundation.h>

void cuslog(NSString *format, ...);

@interface ObjC : NSObject

@end

ObjC.m

#import "ObjC.h"

@implementation ObjC

@end

void cuslog(NSString *format, ...)
{
     // Implementation
}

我在 Bridging-Header.h 中暴露了它:

I exposed it in Bridging-Header.h:

#import "ObjC.h"

// Also tried to put this line in bridging header
void cuslog(NSString *format, ...);

在 Swift 中，我打算这样调用函数:

In Swift I intend to call the function like this:

cuslog("Some log")

但错误说:

"Use of unresolved identifier 'cuslog'"

在 Swift 中调用函数的正确方法是什么?

What is the correct way to call the function in Swift?

推荐答案

根据 Swift 开发者的说法，C 可变参数函数与 Swift 可变参数函数不兼容，因此您将无法直接调用您的函数.

According to the Swift devs, C variadic functions are not compatible with Swift variadics, so you won't be able to call your function directly.

目前唯一的解决方法是用 C 或 Obj-C 编写一个非可变参数包装器，并从 Swift 中调用它.

The only workaround at this time is to write a non-variadic wrapper in C or Obj-C, and call that from Swift.

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