C#中调用unmanaged DLL

时间:2023-03-08 15:23:43
C#中调用unmanaged DLL

using
System;

using
System.Collections.Generic;

using
System.ComponentModel;

using
System.Data;

using
System.Drawing;

using
System.Linq;

using
System.Text;

using
System.Windows.Forms;

using
System.Diagnostics; // for Process

using
System.Runtime.InteropServices; // for DllImport

 

namespace
ZSICReaderDemo

{

public
partial
class
Form1 : Form

{

public
Form1()

{

InitializeComponent();

}

 

[DllImport("ZSICReader.DLL")]

public
static
extern
bool
LinkReader();

 

[DllImport("ZSICReader.DLL")]

public
static
extern
bool
StopReader();

 

[StructLayout(LayoutKind.Sequential)] // 调用C++DLL必须使用 LayoutKind.Sequential

// 接口体需要讲参数类型进行转换

public
struct
CONSUMERINFO

{

public
uint
ulNum; // 用户编号

[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 100)]

public
string
strCardNum; // 卡序号

public
uint
ulCardNo; // 卡内码

[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 100)]

public
string
strName; // 姓名

[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 100)]

public
string
strSex; // 性别

[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 100)]

public
string
strDepartment; // 部门名称

[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 100)]

public
string
strSort; // 人员类别

[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 100)]

public
string
strAddr; // 地址

[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 100)]

public
string
strCertificate; // 证件号

public
double
dbCardfee; // 卡押金

public
double
dbLeftMoney; // 余额

public
double
dbSubsidyMoney; //补助金额

 

public
uint
lDepartment; // 部门编号

public
uint
lSort; // 人员类别编号

 

public
bool
bGS; // 挂失状态

public
bool
bDestroy; // 注销状态

public
uint
ulPsw; // 大额消费密码

 

public
uint
lTimes; // 卡使用次数

 

public
double
dbTJSKLeftMoney; // 脱机水控余额

public
uint
lTJSKCardTimes; // 脱机水控卡次数

 

public
uint
lJiFen; // 积分值

[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 100)]

public
string
strContact; // 联系方式

}

 

[DllImport("ZSICReader.DLL", CharSet = CharSet.Ansi, SetLastError = false)]

public
static
extern
bool
ReadCardInfo(ref
CONSUMERINFO
ConsumerInfo);

 

// 由于DLL中使用了打开了系统串口,所以必须手动调用FreeLibrary释放资源,否则主程序退出DLL时DLL_PROCESS_DETACH会出错

[DllImport("Kernel32")]

public
static
extern
int
FreeLibrary(IntPtr
hModule);

 

private
void
button1_Click(object
sender, EventArgs
e)

{

try

{

if (LinkReader())

{

MessageBox.Show("连接读卡器成功!");

 

}

else

{

MessageBox.Show("连接读卡器失败!");

 

}

}

catch (System.Exception
ex)

{

 

}

 

}

 

private
void
button2_Click(object
sender, EventArgs
e)

{

try

{

if (StopReader())

{

MessageBox.Show("停止读卡器成功!");

}

else

{

MessageBox.Show("停止读卡器失败!");

}

}

catch (System.Exception
ex)

{

 

}

}

 

private
void
button3_Click(object
sender, EventArgs
e)

{

try

{

CONSUMERINFO
ConsumerInfo = new
CONSUMERINFO();

 

if (ReadCardInfo(ref
ConsumerInfo))

{

MessageBox.Show("读取卡信息成功");

MessageBox.Show("卡序号:" + ConsumerInfo.ulCardNo.ToString());

MessageBox.Show("用户编号:" + ConsumerInfo.ulNum.ToString());

MessageBox.Show("姓名:" + ConsumerInfo.strName);

MessageBox.Show("性别:" + ConsumerInfo.strSex);

MessageBox.Show("卡余额:" + ConsumerInfo.dbLeftMoney.ToString());

 

}

else

{

MessageBox.Show("读取卡信息失败");

}

}

catch (System.Exception
ex)

{

 

}

}

 

private
void
Form1_FormClosing(object
sender, FormClosingEventArgs
e)

{

try

{ // 在关闭窗口时释放引用的链接库

foreach (ProcessModule
mod
in
Process.GetCurrentProcess().Modules)

{

if (mod.ModuleName == "ZSICReader.DLL")

{

FreeLibrary(mod.BaseAddress);

}

}

}

catch (System.Exception
ex)

{

 

}

}

}

}

 

注意:在C#项目中调试unmanaged dll时需要在项目设置里启用允许调试非托管代码。
关于如何手工卸载DLL详见这里Unload a DLL loaded using DllImport。摘要如下:

C#中调用unmanaged DLL

原始C的接口定义是这样的:

typedef
struct
_CONSUMERINFO

{

ULONG
ulNum;

char
strCardNum[100];

ULONG
ulCardNo;

char
strName[100];

char
strSex[100];

char
strDepartment[100];

char
strSort[100];

char
strAddr[100];

char
strCertificate[100];

double
dbCardfee;

double
dbLeftMoney;

double
dbSubsidyMoney;

 

long
lDepartment;

long
lSort;

 

bool
bGS;

bool
bDestroy;

ULONG
ulPsw;

 

long
lTimes;

 

double
dbTJSKLeftMoney;

long
lTJSKCardTimes;

 

long
lJiFen;

char
strContact[100];

} CONSUMERINFO;

 

BOOL
WINAPI
LinkReader();

BOOL
WINAPI
StopReader();

BOOL
WINAPI
ReadCardInfo(CONSUMERINFO *ConsumerInfo);

 

对比之前的C#代码,可以知道如何将C++结构转换为C#可以调用的结构了。

为了方便查看C#与C++结构的转换,引用http://www.cnblogs.com/lizi/archive/2012/02/22/2363181.html
做了个表格:

C++类型

C#类型

基本类型

 

Handle

IntPtr

Hwnd

IntPtr

int*

ref int

int&

ref int

void*

IntPtr

unsigned char*

ref byte

BOOL

Bool

DWORD

int 或 uint

char**

作为输入参数转为char[],通过Encoding类对这个string[]进行编码后得到的一个char[]

作为输出参数转为byte[],通过Encoding类对这个byte[]进行解码,得到字符串

C++ Dll接口:

void CplusplusToCsharp(in char** AgentID, out char** AgentIP);

C#中的声明:

[DllImport("Example.dll")]

public static extern void CplusplusToCsharp(char[] AgentID, byte[] AgentIP);

C#中的调用:

Encoding encode = Encoding.Default;

byte[] tAgentID;

byte[] tAgentIP;

string[] AgentIP;

tAgentID = new byte[100];

tAgentIP = new byte[100];

CplusplusToCsharp(encode.GetChars(tAgentID), tAgentIP);

AgentIP[i] = encode.GetString(tAgentIP,i*Length,Length);

枚举类型

 

BOOL MessageBeep(UINT uType // 声音类型); 其中的声音类型为枚举类型中的某一值。

用户需要自己定义一个枚举类型:

public enum BeepType

{

  SimpleBeep = -1,

  IconAsterisk = 0x00000040,

  IconExclamation = 0x00000030,

  IconHand = 0x00000010,

  IconQuestion = 0x00000020,

  Ok = 0x00000000,

}

C#中导入该函数:

[DllImport("user32.dll")]

public static extern bool MessageBeep(BeepType beepType);

C#中调用该函数:

MessageBeep(BeepType.IconQuestion);

结构体

 

使用结构指针作为参数的函数:

BOOL GetSystemPowerStatus(

 LPSYSTEM_POWER_STATUS lpSystemPowerStatus

);

Win32中该结构体的定义:

typedef struct _SYSTEM_POWER_STATUS {

BYTE  ACLineStatus;

BYTE  BatteryFlag;

BYTE  BatteryLifePercent;

BYTE  Reserved1;

DWORD BatteryLifeTime;

DWORD BatteryFullLifeTime;

} SYSTEM_POWER_STATUS, *LPSYSTEM_POWER_STATUS;

使用结构指针作为参数的函数:

BOOL GetSystemPowerStatus(

 LPSYSTEM_POWER_STATUS lpSystemPowerStatus

);

Win32中该结构体的定义:

typedef struct _SYSTEM_POWER_STATUS {

BYTE  ACLineStatus;

BYTE  BatteryFlag;

BYTE  BatteryLifePercent;

BYTE  Reserved1;

DWORD BatteryLifeTime;

DWORD BatteryFullLifeTime;

} SYSTEM_POWER_STATUS, *LPSYSTEM_POWER_STATUS;

字符串

 

对于字符串的处理分为以下几种情况:

1、
字符串常量指针的处理(LPCTSTR),也适应于字符串常量的处理,.net中的string类型是不可变的类型。

2、
字符串缓冲区的处理(char*),即对于变长字符串的处理,.net中StringBuilder可用作缓冲区

Win32:

BOOL GetFile(LPCTSTR lpRootPathName);

函数声明:

[DllImport("kernel32.dll", CharSet = CharSet.Auto)]

static extern bool GetFile (

 [MarshalAs(UnmanagedType.LPTStr)]

 string rootPathName);

函数调用:

string pathname;

GetFile(pathname);

备注:

DllImport中的CharSet是为了说明自动地调用该函数相关的Ansi版本或者Unicode版本

 
 

变长字符串处理:

C#:

函数声明:

[DllImport("kernel32.dll", CharSet = CharSet.Auto)]

public static extern int GetShortPathName(

  [MarshalAs(UnmanagedType.LPTStr)]

  string path,

  [MarshalAs(UnmanagedType.LPTStr)]

  StringBuilder shortPath,

  int shortPathLength);

函数调用:

StringBuilder shortPath = new StringBuilder(80);

int result = GetShortPathName(

@"d:\test.jpg", shortPath, shortPath.Capacity);

string s = shortPath.ToString();

结构体

 

具有内嵌字符数组的结构:

Win32:

typedef struct _TIME_ZONE_INFORMATION {

  LONG    Bias;

  WCHAR   StandardName[ 32 ];

  SYSTEMTIME StandardDate;

  LONG    StandardBias;

  WCHAR   DaylightName[ 32 ];

  SYSTEMTIME DaylightDate;

  LONG    DaylightBias;

} TIME_ZONE_INFORMATION, *PTIME_ZONE_INFORMATION;

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]

struct TimeZoneInformation

{

  public int bias;

  [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]

  public string standardName;

  SystemTime standardDate;

  public int standardBias;

  [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]

  public string daylightName;

  SystemTime daylightDate;

  public int daylightBias;

}

回调函数

 

BOOL EnumDesktops(

 HWINSTA hwinsta,       // 窗口实例的句柄

 DESKTOPENUMPROC lpEnumFunc, // 回调函数

 LPARAM lParam        // 用于回调函数的值

);

回调函数DESKTOPENUMPROC的声明:

BOOL CALLBACK EnumDesktopProc(

 LPTSTR lpszDesktop, // 桌面名称

 LPARAM lParam    // 用户定义的值

);

将回调函数的声明转化为委托:

delegate bool EnumDesktopProc(

 [MarshalAs(UnmanagedType.LPTStr)]

  string desktopName,

  int lParam);

该函数在C#中的声明:

[DllImport("user32.dll", CharSet = CharSet.Auto)]

static extern bool EnumDesktops(

  IntPtr windowStation,

  EnumDesktopProc callback,

  int lParam);