运行时错误49，对Excel/VBA的D语言DLL调用约定不好--我遗漏了什么？
运行时错误49，对Excel/VBA的D语言DLL调用约定不好--我遗漏了什么？
提问于 2019-01-17 17:57:16
我试图从Excel中的VBA中获得尽可能简单的D语言DLL .我使用Visual .首先，我使用C接口D从DLL复制了样板示例，使用以下代码：
module DDLL;
import core.sys.windows.windows;
import core.sys.windows.dll;
__gshared HINSTANCE g_hInst;
extern (Windows)
BOOL DllMain(HINSTANCE hInstance, ULONG ulReason, LPVOID pvReserved)
{
switch (ulReason)
{
case DLL_PROCESS_ATTACH:
g_hInst = hInstance;
dll_process_attach( hInstance, true );
break;
case DLL_PROCESS_DETACH:
dll_process_detach( hInstance, true );
break;
case DLL_THREAD_ATTACH:
dll_thread_attach( true, true );
break;
case DLL_THREAD_DETACH:
dll_thread_detach( true, true );
break;
default:
}
return true;
}我试图从VBA调用的D应用程序代码如下：
module myfns;
export double testdd(double a, double b) { return a + b + 0; }
export int testi(int x) {return 42 + x ; }
export int testii(int a, int b) { return a + b + 0; }VBA代码是：
Option Explicit
Declare Function testdd Lib "C:\Users\vvkozlov\sources\DDLL\Win32\Debug\DDLL.dll" _
Alias "_D5myfns6testddFddZd" (ByVal x As Double, ByVal y As Double) As Double
Declare Function testi Lib "C:\Users\vvkozlov\sources\DDLL\Win32\Debug\DDLL.dll" _
Alias "_D5myfns5testiFiZi" (ByVal x As Long) As Long
Declare Function testii Lib "C:\Users\vvkozlov\sources\DDLL\Win32\Debug\DDLL.dll" _
Alias "_D5myfns6testiiFiiZi" (ByVal x As Long, ByVal y As Long) As Long
Public Sub test()
Dim x As Long: x = 42000
Debug.Print "two doubles: " & testdd(84#, -42#)
Debug.Print "one long: " & testi(x)
Debug.Print "two longs: " & testii(x, -x)
End Sub注意，我进去了，从生成的DLL中找出了损坏的名称。
testdd (两个双倍)示例按预期工作，但两个int示例的结果都是
Runtime Error 49, Bad DLL calling convention在VBA。第一、第二和第三次浏览参数声明似乎很好-- VBA端的Long，D中的int。
为什么double示例在int失败时工作？
回答 1
Stack Overflow用户
发布于 2019-01-18 08:04:26
亚当·D·鲁普的建议是正确的。D应用程序代码现在看起来像
module myfns;
import std.conv;
extern(Windows) export double testdd(double a, double b) { return a + b + 0; }
extern(Windows) export int testi(int x) {return 42 + x ; }
extern(Windows) export int testii(int a, int b) { return a + b + 0; }这也有一个好的副作用，至少简化名称损坏(不，从VBA代码中删除别名不起作用)。
VBA现在看起来就像
Option Explicit
Declare Function testdd Lib "C:\Users\vvkozlov\sources\DDLL\Win32\Debug\DDLL.dll" _
Alias "_testdd@16" (ByVal x As Double, ByVal y As Double) As Double
Declare Function testi Lib "C:\Users\vvkozlov\sources\DDLL\Win32\Debug\DDLL.dll" _
Alias "_testi@4" (ByVal x As Long) As Long
Declare Function testii Lib "C:\Users\vvkozlov\sources\DDLL\Win32\Debug\DDLL.dll" _
Alias "_testii@8" (ByVal x As Long, ByVal y As Long) As Long接下来是BSTR，然后可能是SAFEARRAY。没有Variant。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/54241676
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