我想自定UIActionSheet但的我不知道如何调用它原本的初始方法:
initWithTitle:(nullable NSString *)title delegate:(nullable id<UIActionSheetDelegate>)delegate cancelButtonTitle:(nullable NSString *)cancelButtonTitle destructiveButtonTitle:(nullable NSString *)destructiveButtonTitle otherButtonTitles:(nullable NSString *)otherButtonTitles, ... 
我知道用va_list可能拿到传进来的参数列表,但是不知道如何传递参数列表给父类。自定义类的初始函数:
-(id)initWithTitle:(NSString *)title message:(NSString *)message cancelButtonTitle:(nullable NSString *)cancelButtonTitle destructiveButtonTitle:(nullable NSString *)destructiveButtonTitle buttonClick:(SheetButtonClick)click otherButtonTitles:(nullable NSString *)otherButtonTitles, ...
{
    //xcode提示语法有错
    self=[super initWithTitle:title delegate:self cancelButtonTitle:cancelButtonTitle destructiveButtonTitle:destructiveButtonTitle otherButtonTitles:otherButtonTitles,...,nil];
return self;
}
还有一种写法:
-(id)initWithTitle:(NSString *)title message:(NSString *)message cancelButtonTitle:(nullable NSString *)cancelButtonTitle destructiveButtonTitle:(nullable NSString *)destructiveButtonTitle buttonClick:(SheetButtonClick)click otherButtonTitles:(nullable NSString *)otherButtonTitles, ...
{
    //把...替换为(va_list)params,通过编译但运行会出错
    va_list params;
    self=[super initWithTitle:title delegate:self cancelButtonTitle:cancelButtonTitle destructiveButtonTitle:destructiveButtonTitle otherButtonTitles:otherButtonTitles,params,nil];
return self;
}