20

有人可以在这里发布一个如何在 Delphi 中托管 CLR 的示例吗？我在这里读过类似的问题，但我不能使用 JCL，因为我想在 Delphi 5 中托管它。谢谢。

编辑：这篇关于在 Fox Pro 中托管 CLR 的文章看起来很有希望，但我不知道如何从 Delphi 访问 clrhost.dll。

编辑 2：我放弃了 Delphi 5 的要求。现在我正在尝试使用 Delphi 7 进行 JCL。但我再次找不到任何示例。这是我到目前为止所拥有的：

我的 C# 程序集：

namespace DelphiNET
{
    public class NETAdder
    {
        public int Add3(int left)
        {
            return left + 3;
        }
    }
}

我已将其编译为DelphiNET.dll.

现在我想使用 Delphi 的这个程序集：

uses JclDotNet, mscorlib_TLB;

procedure TForm1.Button1Click(Sender: TObject);
var
  clr: TJclClrHost;
  ads: TJclClrAppDomainSetup;
  ad: TJclClrAppDomain;
  ass: TJclClrAssembly;
  obj: _ObjectHandle;
  ov: OleVariant;
begin
  clr := TJclClrHost.Create();
  clr.Start;
  ads := clr.CreateDomainSetup;
  ads.ApplicationBase := 'C:\Delhi.NET';
  ads.ConfigurationFile := 'C:\Delhi.NET\my.config';
  ad := clr.CreateAppDomain('myNET', ads);
  obj := (ad as _AppDomain).CreateInstanceFrom('DelphiNET.dll', 'DelphiNET.NETAdder');
  ov := obj.Unwrap;
  Button1.Caption := 'done ' + string(ov.Add3(5));
end;

这以错误结束：EOleError: Variant does not reference an automation object

我很长时间没有与Delphi合作，所以我被困在这里......

解决方案： COM 可见性存在问题，默认情况下不存在。这是正确的 .NET 程序集：

namespace DelphiNET
{
    [ComVisible(true)]
    public class NETAdder
    {
        public int Add3(int left)
        {
            return left + 3;
        }
    }
}

重要的提示：

在使用 Delphi 的 .NET 时，Set8087CW($133F);在程序的开头（即在 .NET 之前Application.Initialize;）调用是很重要的。默认情况下，Delphi 启用了浮点异常（请参阅this），而 CLR 不喜欢它们。当我启用它们时，我的程序奇怪地冻结了。

4

5 回答 5

14

这是另一种选择。

这就是 C# 代码。即使您不想使用我的非托管导出，它仍然会解释如何使用 mscoree（CLR 托管的东西）而不通过 IDispatch（IDispatch 非常慢）。

using System;
using System.Collections.Generic;
using System.Text;
using RGiesecke.DllExport;
using System.Runtime.InteropServices;

namespace DelphiNET
{

   [ComVisible(true)]
   [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
   [Guid("ACEEED92-1A35-43fd-8FD8-9BA0F2D7AC31")]
   public interface IDotNetAdder
   {
      int Add3(int left);
   }

   [ComVisible(true)]
   [ClassInterface(ClassInterfaceType.None)]
   public class DotNetAdder : DelphiNET.IDotNetAdder
   {
      public int Add3(int left)
      {
         return left + 3;
      }
   }

   internal static class UnmanagedExports
   {
      [DllExport("createdotnetadder", CallingConvention = System.Runtime.InteropServices.CallingConvention.StdCall)]
      static void CreateDotNetAdderInstance([MarshalAs(UnmanagedType.Interface)]out IDotNetAdder instance)
      {
         instance = new DotNetAdder();
      }
   }
}

这是 Delphi 接口声明：

type
  IDotNetAdder = interface
  ['{ACEEED92-1A35-43fd-8FD8-9BA0F2D7AC31}']
    function Add3(left : Integer) : Integer; safecall;
  end;

如果您使用非托管导出，您可以这样做：

procedure CreateDotNetAdder(out instance :  IDotNetAdder); stdcall;
  external 'DelphiNET' name 'createdotnetadder';

var
  adder : IDotNetAdder;
begin
  try
   CreateDotNetAdder(adder);
   Writeln('4 + 3 = ', adder.Add3(4));
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
end.

当我改编 Lars 的样本时，它看起来像这样：

var
  Host: TJclClrHost;
  Obj: IDotNetAdder;
begin
  try
    Host := TJclClrHost.Create;
    Host.Start();
    WriteLn('CLRVersion = ' + Host.CorVersion);

    Obj := Host.DefaultAppDomain
               .CreateInstance('DelphiNET', 
                               'DelphiNET.DotNetAdder')
               .UnWrap() as IDotNetAdder;
    WriteLn('2 + 3 = ', Obj.Add3(2));

    Host.Stop();
  except
    on E: Exception do
      Writeln(E.Classname, ': ', E.Message);
  end;
end.

在这种情况下，您当然可以从 C# 代码中删除“UnmanagedExports”类。

于 2010-01-13T09:09:00.740 回答
9

类必须是可共见的。如果整个程序集都有 ComVisible(false)，则情况可能并非如此。

默认情况下，.Net 类将与 IDispatch 兼容，因此如果该类确实是可共享的，那么您的示例应该可以正常工作。

但首先将其剥离到最低限度。将您的 exe 放在与 .Net 程序集相同的文件夹中，并跳过配置文件和应用程序库。

在事情变得混乱之前，这里发生了异常，对吧？

 ov := obj.Unwrap;
于 2010-01-12T20:33:50.743 回答
7

干得好：

program CallDotNetFromDelphiWin32;

{$APPTYPE CONSOLE}

uses
  Variants, JclDotNet, mscorlib_TLB, SysUtils;

var
  Host: TJclClrHost;
  Obj: OleVariant;
begin
  try
    Host := TJclClrHost.Create;
    Host.Start;
    WriteLn('CLRVersion = ' + Host.CorVersion);

    Obj := Host.DefaultAppDomain.CreateInstance('DelphiNET', 'DelphiNET.NETAdder').UnWrap;
    WriteLn('2 + 3 = ' + IntToStr(Obj.Add3(2)));

    Host.Stop;
  except
    on E: Exception do
      Writeln(E.Classname, ': ', E.Message);
  end;
end.

注意：假设 DelphiNET.NETAdder 类型和 DelphiNet.dll 中的 Add3 方法是ComVisible。感谢罗伯特。

更新：

使用反射时，您不需要 ComVisible 属性。下一个示例甚至可以在没有 ComVisible 的情况下工作。

Assm := Host.DefaultAppDomain.Load_2('NetAddr');
T := Assm.GetType_2('DelphiNET.NETAdder');
Obj := T.InvokeMember_3('ctor', BindingFlags_CreateInstance, nil, null, nil);
Params := VarArrayOf([2]);
WriteLn('2 + 3 = ' + IntToStr(T.InvokeMember_3('Add3', BindingFlags_InvokeMethod, nil, Obj, PSafeArray(VarArrayAsPSafeArray(Params)))));
于 2010-01-12T20:40:50.117 回答
0

我在使用“TJclClrHost”组件时遇到了一些麻烦（参见 src 代码中的注释）。搜索后，我发现“CppHostCLR”Microsoft 示例是新的接口路径，以便在 Win32/64 应用程序中托管 .NET 运行时...

这是一个用 Delphi 编写的快速（和肮脏）示例版本（也可以在这里找到：http ://chapsandchips.com/Download/DelphiNETHost_v1.zip ）

此示例代码中仅实现了 Delphi 接口（使用“OleVariant”/后期绑定）。

hth，问候。

帕斯卡

unit uDelphiNETHosting;

interface

// Juin 2018 - "CorBindToRuntime*" deprecated API alternative by Pascal Chapuis with "Delphi 10.1 Berlin" version
//
// Sample implementation with .NET 4.0 interfaces defined in "metaHost.h" SDK with Delphi header (partial) source code
// "CLRCreateInstance" (mscorlib) API with "ICLRMetaHost", "ICLRRuntimeInfo", "ICorRuntimeHost" interfaces are used.
//
// This Delphi sample provides :
//  - Delphi Win32 .NET runtime advanced hosting
//  - .NET class late binding interface with Delphi (OleVariant) Win32/64 application (no REGASM is needed)
//  - Interfaced C# class is the same than provided in "CppHostCLR" Microsoft C++ sample available at :
//      https://code.msdn.microsoft.com/windowsdesktop/CppHostCLR-e6581ee0/sourcecode?fileId=21953&pathId=1366553273
//
// This sample was inspired by "TJclClrHost" troubles with "_AppDomain.CreateInstanceFrom" with .NET 4.0 :
//  - "CorBindToRuntime*" = deprecated API : "old-fashion" interfaced library vs. new interfaced COM/Interop API.
//  - AppDomainSetup "ApplicationBase" property (assembly loading with custom path implementation) : no delegated resolver impl.
//  - ComVisible .NET annotation is needed at least at class level or/and assembly level.
//


uses
    mscorlib_TLB, // imported from C:\Windows\Microsoft.NET\Framework\v4.0.30319\mscorlib.tlb
    mscoree_tlb,  // imported from C:\Windows\Microsoft.NET\Framework\v4.0...\mscoree.dll
    System.Classes, Vcl.Controls, Vcl.StdCtrls,
    Windows, Messages, SysUtils, Variants, Graphics, Forms,
    Dialogs, activeX, Vcl.ComCtrls;

Const

  // ICLRMetaHost GUID
  // EXTERN_GUID(IID_ICLRMetaHost, 0xD332DB9E, 0xB9B3, 0x4125, 0x82, 0x07, 0xA1, 0x48, 0x84, 0xF5, 0x32, 0x16);
  IID_ICLRMetaHost : TGuid = '{D332DB9E-B9B3-4125-8207-A14884F53216}';
  // EXTERN_GUID(CLSID_CLRMetaHost, 0x9280188d, 0xe8e, 0x4867, 0xb3, 0xc, 0x7f, 0xa8, 0x38, 0x84, 0xe8, 0xde);
  CLSID_CLRMetaHost : TGuid = '{9280188d-0e8e-4867-b30c-7fa83884e8de}';

  // ICLRRuntimeInfo GUID
  // EXTERN_GUID(IID_ICLRRuntimeInfo, 0xBD39D1D2, 0xBA2F, 0x486a, 0x89, 0xB0, 0xB4, 0xB0, 0xCB, 0x46, 0x68, 0x91);
  IID_ICLRRuntimeInfo   : TGuid   = '{BD39D1D2-BA2F-486A-89B0-B4B0CB466891}';
  CLASS_ICLRRuntimeInfo : TGuid = '{BD39D1D2-BA2F-486a-89B0-B4B0CB466891}';

type

  // .NET interface (defined in "metahost.h" SDK header)
  ICLRRuntimeInfo = interface(IUnknown)
    ['{BD39D1D2-BA2F-486a-89B0-B4B0CB466891}']
    function GetVersionString( pwzBuffer : PWideChar; var pcchBuffer : DWORD) : HResult; stdcall;
    function GetRuntimeDirectory(pwzBuffer : PWideChar; var pcchBuffer : DWORD) : HResult; stdcall;
    function IsLoaded( hndProcess  : THANDLE; out bLoaded : bool): HResult; stdcall;
    function LoadErrorString(iResourceID: UINT; pwzBuffer: PWideChar; var pcchBuffer : DWORD; iLocaleID :LONG): HResult; stdcall;
    function LoadLibrary(pwzDllName : PWideChar; phndModule : PHMODULE): HResult; stdcall;
    function GetProcAddress( pszProcName : PChar; var ppProc : Pointer) : HResult; stdcall;
    function GetInterface( const rclsid : TCLSID;const riid : TIID;  out ppUnk : IUnknown) : HResult;  stdcall;
    function IsLoadable( var pbLoadable :  Bool) : HResult; stdcall;
    function SetDefaultStartupFlags(dwStartupFlags : DWORD; pwzHostConfigFile : LPCWSTR) : HResult; stdcall;
    function GetDefaultStartupFlags(var pdwStartupFlags : PDWORD;pwzHostConfigFile : LPWSTR;var pcchHostConfigFile : DWORD )  : HResult; stdcall;
    function BindAsLegacyV2Runtime() : HResult;  stdcall;
    function IsStarted( var  pbStarted : bool;var pdwStartupFlags : DWORD ) : HResult;  stdcall;
   end;

  // .NET interface (defined in "metahost.h" SDK header)
  ICLRMetaHost = interface(IUnknown)
    ['{D332DB9E-B9B3-4125-8207-A14884F53216}']
    function GetRuntime(pwzVersion: LPCWSTR; const riid: TIID; out ppRuntime : IUnknown): HResult; stdcall;
    function GetVersionFromFile(const pwzFilePath: PWideChar; pwzBuffer: PWideChar; var pcchBuffer: DWORD): HResult; stdcall;
    function EnumerateInstalledRuntimes(out ppEnumerator: IEnumUnknown): HResult; stdcall;
    function EnumerateLoadedRuntimes(const hndProcess: THandle;  out ppEnumerator: IEnumUnknown): HResult; stdcall;
    function RequestRuntimeLoadedNotification(out pCallbackFunction: PPointer): HResult; stdcall;
    function QueryLegacyV2RuntimeBinding(const riid: TGUID;out ppUnk: PPointer): HResult; stdcall;
    procedure ExitProcess(out iExitCode: Int32); stdcall;
  end;

  TSampleForm = class(TForm)
    BtnTest: TButton;
    StatusBar1: TStatusBar;
    Label1: TLabel;
    Label2: TLabel;
    procedure BtnTestClick(Sender: TObject);
  private
    // CLR
    FPtrClr            : ICLRMetaHost;
    // CLR runtime info
    FPtrRunTime        : ICLRRuntimeInfo;
    // CLR Core runtime
    FPtrCorHost        : ICorRuntimeHost;
    FDefaultNetInterface : ICorRuntimeHost;
    //
    Procedure LoadAndBindAssembly();
  public
  end;

  // Main .NET hosting API entry point (before interfaced stuff)
  function CLRCreateInstance(const clsid,iid: TIID; out ppv : IUnknown): HRESULT; stdcall; external 'MSCorEE.dll';

var
  SampleForm: TSampleForm;

implementation

uses //JcldotNet  // original "TJclClrHost" component unit
      math,
      ComObj;     // COM init + uninit

{$R *.dfm}

Procedure TSampleForm.LoadAndBindAssembly();
Const
  NetApp_Base_Dir : WideString  = '.\Debug\';
  Sample_Test_Value             = 3.1415;
var
  hr            : HResult;
  Ov            : OleVariant;
  ws            : WideString;
  iDomAppSetup  : IUnknown;
  iDomApp       : IUnknown;
  // .Net interfaces...
  iDomAppSetup2 : IAppDomainSetup;
  iDomApp2      : AppDomain;
  objNET        : ObjectHandle;
begin
  // Delphi sample : https://adamjohnston.me/delphi-dotnet-interop-with-jvcl/
  // DomainSetup
  hr := FDefaultNetInterface.CreateDomainSetup( iDomAppSetup );
  if ( hr = S_OK) then
  begin
     // Domain Setup Application...
     iDomAppSetup2 := iDomAppSetup as IAppDomainSetup;
     // NB. Set "ApplicationBase" root directory is NOT ok WITHOUT additional "ResolveEventHandler" (cf 1*)
     // https://weblog.west-wind.com/posts/2009/Jan/19/Assembly-Loading-across-AppDomains
     hr := iDomAppSetup2.Set_ApplicationBase( NetApp_Base_Dir );
     //hr := iDomAppSetup2.Set_PrivateBinPath(  NetApp_Base_Dir );
     //hr := iDomAppSetup2.Set_DynamicBase(  NetApp_Base_Dir );
     if ( hr = S_OK ) then
     begin
       hr := iDomAppSetup2.Set_ConfigurationFile('CSClassLibrary.config');
       if ( hr = S_OK ) then
       begin
         hr := FDefaultNetInterface.CreateDomainEx( PWideChar('aNETClassHostSample'), iDomAppSetup2, nil, iDomApp );
         if ( hr = S_OK ) then
         begin
           iDomApp2 := iDomApp as AppDomain;
           iDomApp2.Get_BaseDirectory(ws); // *** Check setup directory is OK
           // CoBindEx... API troubles begins here... alternative (not deprecated implementation) solves them !
           // CreateInstanceFrom Doc : https://msdn.microsoft.com/en-us/library/we62chk6(v=vs.110).aspx
           //hr := (iDomApp as _AppDomain).CreateInstanceFrom( 'C:\Data\dev\delphi\NetHosting\Sample\CppHostCLR\C# and C++\C#,C++\CppHostCLR\CSClassLibrary\obj\Debug\CSClassLibrary.dll', 'CSClassLibrary.CSSimpleObject', objNET );
           hr := iDomApp2.CreateInstanceFrom( NetApp_Base_Dir+'CSClassLibrary.dll', // (1*) : NO ResolveEventHandler => absolute path
                                              'CSClassLibrary.CSSimpleObject', objNET );
           if ( hr = S_OK ) then
           begin
             // *** NB. ***
             // [ComVisible(true)] annotation on class definition is NEEDED (to invoke via late binding with COM)
             // *** and/or ***
             // .NET project option "Make assembly COM visible" (cf. AssemblyInfo.cs) : [assembly: ComVisible(true)]
             ov := objNET.Unwrap;
             ov.FloatProperty := Sample_Test_Value;
             ShowMessage( 'Result FloatProperty=' +FloatToStr( Currency(ov.FloatProperty) ) );  // Interop data type between Delphi and C# (Currency <=> float)
           end
           else ShowMessage( 'CreateInstanceFrom error: ' + SysErrorMessage(hr) );
         end
         else ShowMessage( 'CreateDomainEx error: ' + SysErrorMessage(hr) );
       end
       else ShowMessage( 'Set_ConfigurationFile error: ' + SysErrorMessage(hr) );
     end
     else ShowMessage( 'Set_ApplicationBase error: ' + SysErrorMessage(hr) );
  end
  else  ShowMessage( 'CreateDomainSetup error: ' + SysErrorMessage(hr) );
end;

procedure TSampleForm.BtnTestClick(Sender: TObject);
var
  // CLR status flags
  FLoadable         : Bool;  // framework is loadable ?
  FStarted          : Bool;  // framework is started ?
  FLoaded           : Bool;  // framework is loaded ?

  arrWideChar       : Array[0..30] of WChar;

  lArr              : Cardinal;

  Flags             : DWORD;

  hr1,hr2,hr3       : HResult;
begin

 // Part-1/2 : Host targetted .NET framework version with "CLRCreateInstance" entry point

 //CoInitializeEx(nil,COINIT_APARTMENTTHREADED); //COINIT_MULTITHREADED
 try
    FLoadable := false;
    FStarted  := false;
    FLoaded   := false;
    Flags := $ffff;
    try
     FPtrClr     := nil;
     FPtrRunTime := nil;
     FPtrCorHost := nil;
     hr1 := CLRCreateInstance(CLSID_CLRMetaHost, IID_ICLRMetaHost, IUnknown(FPtrClr) );  //  CLSID + IID
     if ( hr1 = S_OK) then
      begin
        FPtrRunTime := nil;
        hr1 := FPtrClr.GetRuntime( PWideChar('v4.0.30319'), IID_ICLRRuntimeInfo, IUnknown(FPtrRunTime) );
        if ( hr1 = S_OK ) then
        begin
         // Usefull to check overflow in case of wrong API prototype : call second method overflow other results...
         hr1 := FPtrRunTime.IsLoadable( FLoadable );
         hr2 := FPtrRunTime.IsStarted( FStarted, Flags ); // NB. OVERFLOW by defining FLoadable, FLoaded... local var. as "boolean" NOT "Bool"...
         hr3 := FPtrRunTime.IsLoaded( GetCurrentProcess(), FLoaded );
         if ( hr1 = S_OK ) and ( hr2 = S_OK ) and ( hr3 = S_OK ) then
         begin
            if ( not FLoaded ) and ( FLoadable ) and ( not FStarted ) then
            begin
              hr1 := FPtrRunTime.GetInterface( CLASS_CorRuntimeHost, IID_ICorRuntimeHost, IUnknown(FPtrCorHost) ); // IID_ICorRuntimeHost,
              if ( hr1 = S_OK ) then
              begin
                if ( FPtrCorHost <> nil ) then
                    FDefaultNetInterface := (FPtrCorHost  as Iunknown)  as ICorRuntimeHost
                else ; //  NOT available...
              end
              else ShowMessage( 'GetInterface error : ' + SysErrorMessage(hr1) );
            end
            else
            begin
              if (FLoaded and FStarted) then ShowMessage( '.NET Framework version is already loaded and started...')
              else ShowMessage( '.NET Framework version is N0T loadable...');
            end;
          end
          else
          begin
            ShowMessage( 'IID_ICLRRuntimeInfo.IsLoadable error : ' + SysErrorMessage( Min(hr1,hr2) ) );
          end;
        end
        else ShowMessage( 'GetRuntime error : ' + SysErrorMessage(hr1) );
      end
      else ShowMessage( 'CLRCreateInstance error: ' + SysErrorMessage(hr1) );
    Except on e:exception do
      if Assigned( e.InnerException ) then ShowMessage( e.InnerException.ToString )
      else ShowMessage( e.ToString );
    end;
    // Check a call to an assembly...
   if ( Assigned( FDefaultNetInterface )) then
    begin
      lArr := SizeOf( arrWideChar );
      FillChar( arrWideChar, SizeOf(arrWideChar), #0);
      hr1 := FPtrRunTime.GetVersionString( PWideChar(@arrWideChar[0]), lArr);;
      if ( hr1 = S_OK ) then ShowMessage('Framework version '+arrWideChar+' is available...')
      else  ShowMessage( 'GetVersionString error: ' + SysErrorMessage(hr1));
      hr1 := FDefaultNetInterface.Start();
      if ( hr1 <> S_OK ) then ShowMessage( 'CLRCreateInstance error: ' + SysErrorMessage(hr1) );
    end;
 finally
//   if (PtrClr<>nil) then
//   begin
//     PtrClr._Release;
//     //PtrClr := nil;
//   end;
//   if (PtrRunTime<>nil) then
//   begin
//     PtrRunTime._Release;
//  ///   PtrRunTime := nil;
//   end;
//   if (PtrCorHost<>nil) then
//   begin
//     PtrCorHost._Release;
//     //PtrCorHost := nil;
//   end;
   //FDefaultInterface._Release;

  //CoUnInitialize();
 end;

 // Part-2/2 : load, bind a class call sample assembly class with loaded framework...
 LoadAndBindAssembly();

end;

end.
于 2018-06-24T16:08:05.860 回答
0

感谢这个论坛，我找到了将 dll C# 与 Lazarus 一起使用的最佳解决方案：

C＃：

using System;
using System.Collections.Generic;
using System.Text;
using RGiesecke.DllExport;
using System.Runtime.InteropServices;

namespace DelphiNET
{

    [ComVisible(true)]
    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    [Guid("BA7DFB53-6CEC-4ADA-BE5E-16F1A46DFAC5")]
    public interface IDotNetAdder
    {
        int Add3(int left);

        int Mult3(int left);

        string Expr3(string palavra);
    }

    [ComVisible(true)]
    [ClassInterface(ClassInterfaceType.None)]
    public class DotNetAdder : DelphiNET.IDotNetAdder
    {
        public int Add3(int left)
        {
            return left + 3;
        }

        public int Mult3(int left)
        {
            return left * 3;
        }

        public string Expr3(string palavra)
        {
            return palavra + " é a palavra que estou esperando!";
        }
    }

    internal static class UnmanagedExports
    {
        [DllExport("createdotnetadder", CallingConvention = System.Runtime.InteropServices.CallingConvention.StdCall)]
        static void CreateDotNetAdderInstance([MarshalAs(UnmanagedType.Interface)]out IDotNetAdder instance)
        {
            instance = new DotNetAdder();
        }
    }
}

拉撒路：

unit uDLLC01;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs, StdCtrls{, dynlibs};

type

   IDotNetAdder = interface
   ['{BA7DFB53-6CEC-4ADA-BE5E-16F1A46DFAC5}']
    function Add3(left : integer):integer; safecall; {stdcall nao funciona}
    function Mult3(left : integer):integer; safecall;
    function Expr3(left : WideString):WideString; safecall;
   end;

  { TForm1 }
  TForm1 = class(TForm)
    Button1: TButton;
    Label1: TLabel;
    procedure Button1Click(Sender: TObject);
  private
    { private declarations }
  public
    { public declarations }
  end;


var
  Form1: TForm1;

implementation

{stdcall e cdecl work well; cdecl say is C style to Lazarus}
procedure createdotnetadder(out instance:IDotNetAdder); cdecl external 'IDotNetAdder.dll' name 'createdotnetadder';

{$R *.lfm}

{ TForm1 }

procedure TForm1.Button1Click(Sender: TObject);
var
  x     : LongInt = 0;
  y     : LongInt = 0;
  z     : WideString;
  nTam  : integer;
  adder : IDotNetAdder;
begin
  try
     createdotnetadder(adder);
     z := adder.Expr3('Antonio');
     nTam := Length(z);
     x := adder.Add3(4);
     y := adder.Mult3(4);
  finally
     showmessage('4 + 3 = '+ (inttostr(x)));
     showmessage('4 * 3 = '+ (inttostr(y)));
     showmessage('Expressão = ' + String(z));
  end;
end;

end.

观察到 var Z 是 WideString，这是唯一可以用作字符串类型的类型，我尝试了 String、AnsiString 和 PChar 但没有用，它们只返回第一个字符。我有口音问题，比如“Antônio”这个词作为参数发送，我试图找到一个 C# 可以理解的转换器并发回同一个词。

于 2018-09-17T12:59:44.383 回答