Metatrader MQL4：无法在 .mqh 文件中定义函数默认值

发布于 2024-11-05 18:41:10 字数 1056 浏览 0 评论 0原文

我无法理解如何定义库中函数的默认值。默认值往往会被忽略，并且我收到“错误参数计数”错误消息。

这是我的例子。我创建了简单的测试库 experts\libraries\test.mq4：

void test(int i = 0) // Note the default value for "i"
{
}

然后我创建了 .mqh 文件作为 experts\include\test.mqh：

#import "test.ex4"
void test(int i = 0); // Note the default value for "i"
#import

现在我创建简单的专家“experts\simpletest.mq4”：

#include <test.mqh>
int start()
{
    // Should be able to call test() function without providing any arguments,
    // because it has default value.
    // If I change this line to test(0), everything compiles correctly
    test(); // Causes "wrong parameters count" compilation error

    return(0);
}

并且我在 test() 函数调用中收到以下错误：

')' - 错误参数计数

如果我将此函数调用更改为 test(0)，一切都会编译，但我应该能够在不提供任何内容的情况下调用 test() 函数参数，因为我在 .mqh 文件中的第一个参数有默认值，如下所示： void test(int i = 0); 为什么不使用默认值？

我在谷歌上搜索任何线索，但找不到有关此问题的任何参考资料。有人知道吗？

原文

I can't understand how to define default values for functions in my library. Default values tend to be ignored and I get "wrong parameters count" error message.

Here is my example. I created simple test library experts\libraries\test.mq4:

void test(int i = 0) // Note the default value for "i"
{
}

Then I created .mqh file as experts\include\test.mqh:

#import "test.ex4"
void test(int i = 0); // Note the default value for "i"
#import

Now I create simple expert "experts\simpletest.mq4":

#include <test.mqh>
int start()
{
    // Should be able to call test() function without providing any arguments,
    // because it has default value.
    // If I change this line to test(0), everything compiles correctly
    test(); // Causes "wrong parameters count" compilation error

    return(0);
}

And I get the following error for test() function call:

')' - wrong parameters count

If I change this function call to test(0), everything compiles, but I should be able to call test() function without providing any parameters, because I have default value for first parameter in .mqh file, like this: void test(int i = 0);
Why it doesn't use the default value?

I search google for any clue, but can't find any references about this problem. Anybody knows?

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