C#调用C++编写的DLL函数参数传递

                          

               

1. 不返回值的参数

C++ 原型:

bool    SendNewSms(char *szTel, char *szMessage);
    
    

C#引用;

    
    
[ DllImport( "CdmaCard.dll",EntryPoint="SendNewSms")]
public     static     extern    bool SendNewSms(string phone,string msg);
    
    

2. 带返回值(char *)

C++原型:

BOOL GetCardErrorMessage(char *szErrorMessage , int errorCode);
    
    

C#引用

    
    
[ DllImport( "CdmaCard.dll",EntryPoint="GetCardErrorMessage")]
    public     static     extern    int GetCardErrorMessage(StringBuilder msg,int errorCode);

StringBuilder buf = new StringBuilder( 1024); //指定的Buf大小必须大于可能的最大长度
      GetCardErrorMessage(buf, 1);
    
    

3. 带返回值(其他类型)

C++原型:

   BOOL GetSmsSaveStation (int *nSmsStation);
    
    

C#引用

    
    
  [ DllImport( "CdmaCard.dll",EntryPoint="GetSmsSaveStation")]
   public    static    extern   bool GetSmsSaveStation(ref int nStation);
    
    

4. 传递结构体指针(C++填充)

C++原型:

    
    
struct NET_INFO_STRUCT
{
  DWORD nDurationTime; //持续时间
  double nReceiveByte; //接收字节
  double nSendByte;   //发送字节
};
BOOL NetGetConnectDetail(NET_INFO_STRUCT *lpNetInfo);
    
    

C#引用
  

    
    
public struct NET_INFO_STRUCT
{
  public uint nDurationTime; //持续时间
  public double nReceiveByte; //接收字节
  public double nSendByte;   //发送字节
}
[ DllImport( "CdmaCard.dll",EntryPoint="NetGetConnectDetail")]
        public    static    extern   int NetGetConnectDetail(ref NET_INFO_STRUCT pNetInfo);

        NET_INFO_STRUCT netInfo = new NET_INFO_STRUCT();
        NetGetConnectDetail( ref netInfo);
    
    

     
5. 传递结构体数组(C++来填充)
C++原型:

    
    
struct UIM_BOOK_STRUCT
{
  int UimIndex;
  char szName[ 15];
  char szPhone[ 21];
};
int ReadUimAllBook(UIM_BOOK_STRUCT lpUimBookItem[],int nMaxArraySize);
    
    

C#引用

    
    
[ StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)] //可以指定编码类型
public struct UIM_BOOK_STRUCT
{
  public int UimIndex;
  [ MarshalAs(UnmanagedType.ByValTStr, SizeConst= 15)]
  public string szName;
  [ MarshalAs(UnmanagedType.ByValTStr, SizeConst= 21)]
  public string szPhone;
};
[ DllImport( "CdmaCard.dll",EntryPoint="ReadUimAllBook")]
public    static    extern   int ReadUimAllBook([Out] UIM_BOOK_STRUCT [] lpUimBookItem,int nMaxArraySize);
UIM_BOOK_STRUCT[] p = new UIM_BOOK_STRUCT[ 20];
int ret = ReadUimAllBook(p,p.Length);
    
    

6. 注意问题

类型不一致,会导致调用失败,
(1) long 类型,在C++中是4字节的整数,在C#中是8字节的整数;
(2) 字符串类型的设置不正确;

 

以下是几个简单的window调用

    
    
       [ System.Security.SuppressUnmanagedCodeSecurity] // We won't use this maliciously
       [ DllImport("User32.dll", CharSet=CharSet.Auto)]
       public static extern bool ScreenToClient(IntPtr hWnd, ref System.Drawing.Point rect);

       [ System.Security.SuppressUnmanagedCodeSecurity] // We won't use this maliciously
       [ DllImport("User32.dll", CharSet=CharSet.Auto)]
       public static extern bool GetWindowRect(IntPtr hWnd, out System.Drawing.Rectangle rect);

       [ System.Security.SuppressUnmanagedCodeSecurity] // We won't use this maliciously
       [ DllImport("User32.dll", CharSet=CharSet.Auto)]
       public static extern bool UnregisterClass([MarshalAs(UnmanagedType.LPTStr)] string className, IntPtr instanceHandle);
    
    

转自 http://blog.csdn.net/wen158809179/article/details/5704701

           

               

                          

               

1. 不返回值的参数

C++ 原型:

bool    SendNewSms(char *szTel, char *szMessage);
  
  

C#引用;

  
  
[ DllImport( "CdmaCard.dll",EntryPoint="SendNewSms")]
public     static     extern    bool SendNewSms(string phone,string msg);
  
  

2. 带返回值(char *)

C++原型:

BOOL GetCardErrorMessage(char *szErrorMessage , int errorCode);
  
  

C#引用

  
  
[ DllImport( "CdmaCard.dll",EntryPoint="GetCardErrorMessage")]
    public     static     extern    int GetCardErrorMessage(StringBuilder msg,int errorCode);

StringBuilder buf = new StringBuilder( 1024); //指定的Buf大小必须大于可能的最大长度
      GetCardErrorMessage(buf, 1);
  
  

3. 带返回值(其他类型)

C++原型:

   BOOL GetSmsSaveStation (int *nSmsStation);
  
  

C#引用

  
  
  [ DllImport( "CdmaCard.dll",EntryPoint="GetSmsSaveStation")]
   public    static    extern   bool GetSmsSaveStation(ref int nStation);
  
  

4. 传递结构体指针(C++填充)

C++原型:

  
  
struct NET_INFO_STRUCT
{
  DWORD nDurationTime; //持续时间
  double nReceiveByte; //接收字节
  double nSendByte;   //发送字节
};
BOOL NetGetConnectDetail(NET_INFO_STRUCT *lpNetInfo);
  
  

C#引用
  

  
  
public struct NET_INFO_STRUCT
{
  public uint nDurationTime; //持续时间
  public double nReceiveByte; //接收字节
  public double nSendByte;   //发送字节
}
[ DllImport( "CdmaCard.dll",EntryPoint="NetGetConnectDetail")]
        public    static    extern   int NetGetConnectDetail(ref NET_INFO_STRUCT pNetInfo);

        NET_INFO_STRUCT netInfo = new NET_INFO_STRUCT();
        NetGetConnectDetail( ref netInfo);
  
  

     
5. 传递结构体数组(C++来填充)
C++原型:

  
  
struct UIM_BOOK_STRUCT
{
  int UimIndex;
  char szName[ 15];
  char szPhone[ 21];
};
int ReadUimAllBook(UIM_BOOK_STRUCT lpUimBookItem[],int nMaxArraySize);
  
  

C#引用

  
  
[ StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)] //可以指定编码类型
public struct UIM_BOOK_STRUCT
{
  public int UimIndex;
  [ MarshalAs(UnmanagedType.ByValTStr, SizeConst= 15)]
  public string szName;
  [ MarshalAs(UnmanagedType.ByValTStr, SizeConst= 21)]
  public string szPhone;
};
[ DllImport( "CdmaCard.dll",EntryPoint="ReadUimAllBook")]
public    static    extern   int ReadUimAllBook([Out] UIM_BOOK_STRUCT [] lpUimBookItem,int nMaxArraySize);
UIM_BOOK_STRUCT[] p = new UIM_BOOK_STRUCT[ 20];
int ret = ReadUimAllBook(p,p.Length);
  
  

6. 注意问题

类型不一致,会导致调用失败,
(1) long 类型,在C++中是4字节的整数,在C#中是8字节的整数;
(2) 字符串类型的设置不正确;

 

以下是几个简单的window调用

  
  
       [ System.Security.SuppressUnmanagedCodeSecurity] // We won't use this maliciously
       [ DllImport("User32.dll", CharSet=CharSet.Auto)]
       public static extern bool ScreenToClient(IntPtr hWnd, ref System.Drawing.Point rect);

       [ System.Security.SuppressUnmanagedCodeSecurity] // We won't use this maliciously
       [ DllImport("User32.dll", CharSet=CharSet.Auto)]
       public static extern bool GetWindowRect(IntPtr hWnd, out System.Drawing.Rectangle rect);

       [ System.Security.SuppressUnmanagedCodeSecurity] // We won't use this maliciously
       [ DllImport("User32.dll", CharSet=CharSet.Auto)]
       public static extern bool UnregisterClass([MarshalAs(UnmanagedType.LPTStr)] string className, IntPtr instanceHandle);
  
  

转自 http://blog.csdn.net/wen158809179/article/details/5704701