托管调试助手“PInvokeStackImbalance”检测到...

Question

我从 C# 调用 Delphi 函数并得到错误：

托管调试助手“PInvokeStackImbalance”在...中检测到问题

我已经尝试过更改 .Net 代码以适应 Delphi 签名，为什么它不能与基本整数一起使用让我很困惑，有人知道我哪里出错了吗？

即使是使用 2 个整数的最简单的函数也会产生错误。

我的目标是 x86，并进行了几个小时的研究，但以下解决方案没有帮助 here， here 和 here 和这个 one。

这是Delphi代码（编译好的DLL版本可以从here下载）：

unit PasBallEntry;
interface

procedure EntryPoint( InInt: integer; InStr: PChar;
                      var OutInt: integer; var OutStr: PChar); stdcall;

procedure ReleaseString( OutStr: PChar); stdcall;


procedure TimTamC( InInt: integer; InStr: PChar;
                   var OutInt: integer; var OutStr: PChar); cdecl;

procedure ReleaseStringC( OutStr: PChar); cdecl;

procedure TimTamCS( InInt: integer; InStr: PChar;
                    var OutInt: integer; var OutStr: PChar); cdecl; stdcall;

procedure ReleaseStringCS( OutStr: PChar); cdecl; stdcall;

procedure OneTwoS( var A, B: integer); stdcall;
procedure OneTwoC( var A, B: integer); cdecl;
procedure OneTwoCS( var A, B: integer); cdecl; stdcall;

exports
EntryPoint    name 'TimTam',
ReleaseString name 'ReleaseString';

implementation

uses Windows, SyncObjs, Classes, Generics.Collections;

var
  Gate: TCriticalSection;
  Strs: TStrings;
  StrP: TList<PChar>;

procedure EntryPoint( InInt: integer; InStr: PChar;
                      var OutInt: integer; var OutStr: PChar);
var
  InStrL, OutStrL: string;
begin
  OutInt  := 2 * InInt;
  InStrL  := InStr;
  OutStrL := InStrL + '_OUT!';
  UniqueString( OutStrL);
  if OutStrL = '' then
      OutStr := nil
    else
      begin
      OutStr := PChar( OutStrL);
      Gate.Enter;
      Strs.Add( OutStrL);
      StrP.Add( OutStr );
      Gate.Leave
      end
end;

procedure ReleaseString( OutStr: PChar);
var
  I: integer;
begin
  if not assigned( OutStr) then exit;
  Gate.Enter;
  StrP.Insert( I, OutStr);
  if I >= 0 then
    begin
    StrP.Delete( I);
    Strs.Delete( I)
    end;
  Gate.Leave
end;

procedure TimTamC( InInt: integer; InStr: PChar;
                   var OutInt: integer; var OutStr: PChar);
begin
  EntryPoint( InInt, InStr, OutInt, OutStr)
end;

procedure ReleaseStringC( OutStr: PChar);
begin
  ReleaseString( OutStr)
end;

procedure TimTamCS( InInt: integer; InStr: PChar;
                    var OutInt: integer; var OutStr: PChar);
begin
  EntryPoint( InInt, InStr, OutInt, OutStr)
end;

procedure ReleaseStringCS( OutStr: PChar);
begin
  ReleaseString( OutStr)
end;

procedure OneTwoS( var A, B: integer);
begin
  A := 1;
  B := 2
end;

procedure OneTwoC( var A, B: integer);
begin
  A := 1;
  B := 2
end;

procedure OneTwoCS( var A, B: integer);
begin
  A := 1;
  B := 2
end;

initialization
  Gate := TCriticalSection.Create;
  Strs := TStringList.Create;
  StrP := TList<PChar>.Create

finalization
  Strs.Free;
  Gate.Free;
  StrP.Free

end.

这是.Net代码：

[DllImport("PascalBall.dll", EntryPoint = "TimTam", CallingConvention = CallingConvention.Cdecl)]
public static extern void OneTwoC(ref int a, ref int b);

[DllImport("PascalBall.dll", EntryPoint = "TimTam", CallingConvention = CallingConvention.StdCall)]
public static extern void OneTwoS(ref int a, ref int b);

[DllImport("PascalBall.dll", EntryPoint = "TimTam", CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Unicode)]
public static extern void TimTamC(int inputInt, string inputString, ref int outputInt, ref string outputString);

private void button1_Click(object sender, EventArgs e)
{
    int a = 0;
    int b = 0;

    //Both these PInvoke calls fail (either StdCall or Cdecl)
    OneTwoS(ref a, ref b);

    OneTwoC(ref a, ref b);

    System.Diagnostics.Debug.WriteLine(a + b);
}

private void button2_Click(object sender, EventArgs e)
{
    int outInt = 1;
    string outStr = "world";
    const int stringBufferSize = 1024;
    var outputStringBuffer = new String('\x00', stringBufferSize);

    try
    {
        TimTamC(1, outputStringBuffer, ref outInt, ref outputStringBuffer);
        ReleaseString(ref outStr);
    }
    catch (Exception ex)
    {
    }
}

编辑 1：我认为我使用 TimTam 获得了正确的入口点，因为如果我尝试其他任何方法，我会得到 System.EntryPointNotFoundException，看这里：

Answer 1

这里有很多错误。眼前的问题在这里：

[DllImport("PascalBall.dll", EntryPoint = "TimTam", CallingConvention = CallingConvention.Cdecl)]
public static extern void OneTwoC(ref int a, ref int b);

[DllImport("PascalBall.dll", EntryPoint = "TimTam", CallingConvention = CallingConvention.StdCall)]
public static extern void OneTwoS(ref int a, ref int b);

为什么要指定EntryPoint = "TimTam"？该函数不是您要导入的函数，并且具有不兼容的签名。因此堆栈不平衡错误。

您需要通过将OneTwoS 和OneTwoC 添加到Delphi exports 子句中来导出它们。您需要通过删除错误的EntryPoint 规范在C# 中导入这些函数。

您使用字符串的函数也是错误的，如果不更改代码的两边就无法修复。简单的解决方法是在 Delphi 中使用WideString 参数，var 参数。将其映射到 C# 中的 ref string，编组为 UnmanagedType.BStr。您在 cmets 中链接的答案向您展示了如何：https://stackoverflow.com/a/26043567/495455