delphi dll编写与调用

library mydll;uses
System.SysUtils,
System.Classes,
uFunction in 'uFunction.pas';{$R *.res}exports
AddInt,
AddStr,
AddDouble,
Add;end.

unit uFunction;interfaceuses
System.SysUtils, System.Classes, Winapi.Messages;function AddInt(a1: Integer; a2: Integer): Integer; stdcall;
function AddStr(a1: PWideChar; a2: PWideChar): PWideChar; stdcall;
function AddDouble(a1: Double; a2: Double): Double; stdcall;
function Add(a1: Integer; a2: Integer): PWideChar; stdcall;implementationfunction AddInt(a1: Integer; a2: Integer): Integer; stdcall;
begin
Result := a1 + a2;
end;function AddStr(a1: PWideChar; a2: PWideChar): PWideChar; stdcall;
begin
Result := PWideChar(string(a1) + string(a2));
end;function AddDouble(a1: Double; a2: Double): Double; stdcall;
begin
result:= a1 + a2;
end;function Add(a1: Integer; a2: Integer): PWideChar; stdcall;
begin
Result := PWideChar((a1 + a2).ToString);
end;end.

unit uMain;interfaceuses
Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;type
TForm1 = class(TForm)
Button1: TButton;
Button2: TButton;
Button3: TButton;
Button4: TButton;
procedure Button1Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure Button2Click(Sender: TObject);
procedure Button3Click(Sender: TObject);
procedure Button4Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;var
Form1: TForm1;function AddInt(a1: Integer; a2: Integer): Integer; stdcall; external 'mydll.dll';
function AddStr(a1: PWideChar; a2: PWideChar): PWideChar; stdcall; external 'mydll.dll';
function AddDouble(a1: Double; a2: Double): Double; stdcall; external 'mydll.dll';
function Add(a1: Integer; a2: Integer): PWideChar; stdcall; external 'mydll.dll';implementation{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);
begin
ShowMessage(AddInt(, ).ToString);
end;procedure TForm1.Button2Click(Sender: TObject);
begin
ShowMessage(string(AddStr('hello ', 'world')));
end;procedure TForm1.Button3Click(Sender: TObject);
begin
ShowMessage(AddDouble(5.1, 6.1).ToString);
end;procedure TForm1.Button4Click(Sender: TObject);
begin
ShowMessage(string(Add(, )));
end;procedure TForm1.FormCreate(Sender: TObject);
begin
Position := poScreenCenter;
end;end.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;namespace hello_dll
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
} [DllImport("mydll.dll", CharSet = CharSet.Unicode, CallingConvention = CallingConvention.StdCall)]
public static extern int AddInt(int a1, int a2); [DllImport("mydll.dll", CharSet = CharSet.Unicode, CallingConvention = CallingConvention.StdCall)]
public static extern IntPtr AddStr(string a1, string a2); [DllImport("mydll.dll", CharSet = CharSet.Unicode, CallingConvention = CallingConvention.StdCall)]
public static extern double AddDouble(double a1, double a2); [DllImport("mydll.dll", CharSet = CharSet.Unicode, CallingConvention = CallingConvention.StdCall)]
public static extern IntPtr Add(int a1, int a2); private void Form1_Load(object sender, EventArgs e)
{
StartPosition = FormStartPosition.CenterScreen;
} private void button1_Click(object sender, EventArgs e)
{
MessageBox.Show(AddInt(, ).ToString());
} private void button2_Click(object sender, EventArgs e)
{
IntPtr ptr = AddStr("hello ", "world");
string str = Marshal.PtrToStringUni(ptr);
MessageBox.Show(str);
} private void button3_Click(object sender, EventArgs e)
{
MessageBox.Show(AddDouble(5.1, 6.1).ToString());
} private void button4_Click(object sender, EventArgs e)
{
IntPtr ptr = Add(, );
string str = Marshal.PtrToStringUni(ptr);
MessageBox.Show(str);
}
}
}