从 C# 调用 Delphi 函数
Call Delphi Function From C#
我有下面的DLL源代码。
library Project1;
uses
System.SysUtils,
System.Classes;
type
IStringFunctions = interface
['{240B567B-E619-48E4-8CDA-F6A722F44A71}']
function GetMethodValueAsString():PAnsiChar; stdcall;
end;
TStringFunctions = class(TInterfacedObject, IStringFunctions)
public
function GetMethodValueAsString():PAnsiChar; stdcall;
end;
{$R *.res}
function TStringFunctions.GetMethodValueAsString():PAnsiChar; stdcall;
begin
Result := 'test';
end;
procedure GetImplementation(out instance:IStringFunctions); stdcall; export;
begin
instance := TStringFunctions.Create;
end;
exports GetImplementation;
begin
end.
我想像这样在 C# 中使用
using System;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
namespace ConsoleApplication1
{
[ComVisible(true)]
[ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("240B567B-E619-48E4-8CDA-F6A722F44A71")]
public interface IStringFunctions
{
[MethodImplAttribute(MethodImplOptions.PreserveSig)]
[return: MarshalAs(UnmanagedType.AnsiBStr)]
string GetMethodValueAsString();
}
class Program
{
[DllImport("kernel32.dll", EntryPoint = "LoadLibrary", CallingConvention = CallingConvention.StdCall)]
static extern int LoadLibrary([MarshalAs(UnmanagedType.LPStr)] string lpLibFileName);
[DllImport("kernel32.dll", EntryPoint = "GetProcAddress", CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Ansi)]
static extern IntPtr GetProcAddress(int hModule, [MarshalAs(UnmanagedType.LPStr)] string lpProcName);
[DllImport("kernel32.dll", EntryPoint = "FreeLibrary", CallingConvention = CallingConvention.StdCall)]
static extern bool FreeLibrary(int hModule);
[UnmanagedFunctionPointer(CallingConvention.StdCall, CharSet = CharSet.Ansi)]
delegate void GetImplementation([MarshalAs(UnmanagedType.Interface)] out IStringFunctions instance);
static void Main(string[] args)
{
const string dllName = "Project1.dll";
const string functionName = "GetImplementation";
int libHandle = LoadLibrary(dllName);
if (libHandle == 0) throw new Exception(string.Format("Could not load library \"{0}\"", dllName));
var delphiFunctionAddress = GetProcAddress(libHandle, functionName);
if (delphiFunctionAddress == IntPtr.Zero) throw new Exception(string.Format("Can't find function \"{0}\" in library \"{1}\"", functionName, dllName));
GetImplementation getImplementation = (GetImplementation)Marshal.GetDelegateForFunctionPointer(delphiFunctionAddress, typeof(GetImplementation));
if (getImplementation != null)
{
IStringFunctions instance = null;
getImplementation(out instance);
if (instance != null)
{
//!!! don't return value !!!!
String result = instance.GetMethodValueAsString();
Console.WriteLine(result);
}
}
Console.ReadLine();
}
}
}
但是 instance.GetMethodValueAsString 方法不起作用。和退出代码。
我想在 c# 中使用 dll 函数 (GetMethodValueAsString) 的返回值。
没看懂
我错在哪里?
非常感谢
Delphi DLL 是否对您的 COM Interop 的 C# 代码可见?如果没有,最简单的方法是使用 "Add Existing Item" 菜单选项将 dll 附加到 C# class 库项目。然后在该 dll 的属性 window 中将 "BuildAction" 设置为 None,并将 "Copy to Output Directory" 设置为 "Copy always"
然后你可以在 C# 代码中做这样的事情。
[DllImport("Project1.dll", CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Ansi)]
public static extern string GetMethodValueAsString();
然后你可以在任何需要调用该函数的地方做
var outputMessage = GetMethodValueAsString();
Console.WriteLine(outputMessage);
[return: MarshalAs(UnmanagedType.AnsiBStr)]
这是错误的。您没有 returning 分配在 COM 堆上的 ANSI 编码字符串。您正在 return 一个纯 C 字符串,一个指向以 null 结尾的 ANSI 字符数组的指针。
你的接口声明应该是:
[MethodImplAttribute(MethodImplOptions.PreserveSig)]
IntPtr GetMethodValueAsString();
必须这样调用方法:
IntPtr ptr = instance.GetMethodValueAsString();
string result = Marshal.PtrToStringAnsi(ptr);
当然,当您需要 return 动态分配的字符串时,您的界面设计变得相当不切实际。您还需要导出一个解除分配器。处理这个问题的干净方法是使用 BSTR
。像这样:
Delphi
IStringFunctions = interface
['{240B567B-E619-48E4-8CDA-F6A722F44A71}']
procedure GetMethodValueAsString(out value: WideString); stdcall;
end;
C#
[MethodImplAttribute(MethodImplOptions.PreserveSig)]
void GetMethodValueAsString([MarshalAs(UnmanagedType.BStr)] out string result);
我有下面的DLL源代码。
library Project1;
uses
System.SysUtils,
System.Classes;
type
IStringFunctions = interface
['{240B567B-E619-48E4-8CDA-F6A722F44A71}']
function GetMethodValueAsString():PAnsiChar; stdcall;
end;
TStringFunctions = class(TInterfacedObject, IStringFunctions)
public
function GetMethodValueAsString():PAnsiChar; stdcall;
end;
{$R *.res}
function TStringFunctions.GetMethodValueAsString():PAnsiChar; stdcall;
begin
Result := 'test';
end;
procedure GetImplementation(out instance:IStringFunctions); stdcall; export;
begin
instance := TStringFunctions.Create;
end;
exports GetImplementation;
begin
end.
我想像这样在 C# 中使用
using System;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
namespace ConsoleApplication1
{
[ComVisible(true)]
[ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("240B567B-E619-48E4-8CDA-F6A722F44A71")]
public interface IStringFunctions
{
[MethodImplAttribute(MethodImplOptions.PreserveSig)]
[return: MarshalAs(UnmanagedType.AnsiBStr)]
string GetMethodValueAsString();
}
class Program
{
[DllImport("kernel32.dll", EntryPoint = "LoadLibrary", CallingConvention = CallingConvention.StdCall)]
static extern int LoadLibrary([MarshalAs(UnmanagedType.LPStr)] string lpLibFileName);
[DllImport("kernel32.dll", EntryPoint = "GetProcAddress", CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Ansi)]
static extern IntPtr GetProcAddress(int hModule, [MarshalAs(UnmanagedType.LPStr)] string lpProcName);
[DllImport("kernel32.dll", EntryPoint = "FreeLibrary", CallingConvention = CallingConvention.StdCall)]
static extern bool FreeLibrary(int hModule);
[UnmanagedFunctionPointer(CallingConvention.StdCall, CharSet = CharSet.Ansi)]
delegate void GetImplementation([MarshalAs(UnmanagedType.Interface)] out IStringFunctions instance);
static void Main(string[] args)
{
const string dllName = "Project1.dll";
const string functionName = "GetImplementation";
int libHandle = LoadLibrary(dllName);
if (libHandle == 0) throw new Exception(string.Format("Could not load library \"{0}\"", dllName));
var delphiFunctionAddress = GetProcAddress(libHandle, functionName);
if (delphiFunctionAddress == IntPtr.Zero) throw new Exception(string.Format("Can't find function \"{0}\" in library \"{1}\"", functionName, dllName));
GetImplementation getImplementation = (GetImplementation)Marshal.GetDelegateForFunctionPointer(delphiFunctionAddress, typeof(GetImplementation));
if (getImplementation != null)
{
IStringFunctions instance = null;
getImplementation(out instance);
if (instance != null)
{
//!!! don't return value !!!!
String result = instance.GetMethodValueAsString();
Console.WriteLine(result);
}
}
Console.ReadLine();
}
}
}
但是 instance.GetMethodValueAsString 方法不起作用。和退出代码。
我想在 c# 中使用 dll 函数 (GetMethodValueAsString) 的返回值。
没看懂
我错在哪里?
非常感谢
Delphi DLL 是否对您的 COM Interop 的 C# 代码可见?如果没有,最简单的方法是使用 "Add Existing Item" 菜单选项将 dll 附加到 C# class 库项目。然后在该 dll 的属性 window 中将 "BuildAction" 设置为 None,并将 "Copy to Output Directory" 设置为 "Copy always"
然后你可以在 C# 代码中做这样的事情。
[DllImport("Project1.dll", CallingConvention = CallingConvention.StdCall, CharSet = CharSet.Ansi)]
public static extern string GetMethodValueAsString();
然后你可以在任何需要调用该函数的地方做
var outputMessage = GetMethodValueAsString();
Console.WriteLine(outputMessage);
[return: MarshalAs(UnmanagedType.AnsiBStr)]
这是错误的。您没有 returning 分配在 COM 堆上的 ANSI 编码字符串。您正在 return 一个纯 C 字符串,一个指向以 null 结尾的 ANSI 字符数组的指针。
你的接口声明应该是:
[MethodImplAttribute(MethodImplOptions.PreserveSig)]
IntPtr GetMethodValueAsString();
必须这样调用方法:
IntPtr ptr = instance.GetMethodValueAsString();
string result = Marshal.PtrToStringAnsi(ptr);
当然,当您需要 return 动态分配的字符串时,您的界面设计变得相当不切实际。您还需要导出一个解除分配器。处理这个问题的干净方法是使用 BSTR
。像这样:
Delphi
IStringFunctions = interface
['{240B567B-E619-48E4-8CDA-F6A722F44A71}']
procedure GetMethodValueAsString(out value: WideString); stdcall;
end;
C#
[MethodImplAttribute(MethodImplOptions.PreserveSig)]
void GetMethodValueAsString([MarshalAs(UnmanagedType.BStr)] out string result);