c# - Marshall struct 通过 sendmessage 将其传递给 delphi 记录
问题描述
我正在尝试通过 c# 将结构传递给 delphi,我已经完成以下操作来传递消息,我按照 pinvoke 的格式从https://www.pinvoke.net/default.aspx/Structures.COPYDATASTRUCT复制 datat 结构,但在德尔福我没有收到任何消息。在某种程度上,我相信这是因为我没有以正确的方式对结构进行编码。当我只传递一个字符串消息时,我会收到它,但是当我尝试传递结构时,什么都没有
这是我到目前为止所做的。
using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace ccTestForm2
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
SendFingerPrintResult();
}
const int WM_COPYDATA = 0x004A;
//include SendMessage
[DllImport("user32.dll")]
public static extern IntPtr FindWindow(string lpszClass, string
lpszWindow);
[DllImport("user32.dll", CharSet = CharSet.Ansi, EntryPoint = "SendMessage", SetLastError = false)]
public static extern int SendMessageCopyData(IntPtr hWnd, int uMsg, UIntPtr wParam, ref COPYDATASTRUCT lParam);
[StructLayout(LayoutKind.Sequential)]
public struct COPYDATASTRUCT
{
public IntPtr dwData;
public int cbData;
public IntPtr lpData;
}
public struct ReturnStruct
{
public int i;
public string card;
public string name;
public string responsecode;
public string responsetext;
public string approval;
public string tranid;
public string reference;
public double d;
public string transactionType;
public string creditCardType;
public int EMVContact;
public string applicationName;
public string applicationIdentifier;
public string reserved;
public IntPtr ToPtr()
{
IntPtr ret = Marshal.AllocHGlobal(473);
IntPtr ptr = ret;
Marshal.WriteInt32(ptr, i); ptr = IntPtr.Add(ptr, 4);
DelphiShortStringHelper.WriteToPtr(card, ref ptr, 50);
DelphiShortStringHelper.WriteToPtr(name, ref ptr, 100);
DelphiShortStringHelper.WriteToPtr(responsecode, ref ptr, 5);
DelphiShortStringHelper.WriteToPtr(responsetext, ref ptr, 100);
DelphiShortStringHelper.WriteToPtr(approval, ref ptr, 15);
DelphiShortStringHelper.WriteToPtr(tranid, ref ptr, 50);
DelphiShortStringHelper.WriteToPtr(reference, ref ptr, 16);
Marshal.Copy(new double[] { d }, 0, ptr, 1); ptr = IntPtr.Add(ptr, 8);
DelphiShortStringHelper.WriteToPtr(transactionType, ref ptr, 24);
DelphiShortStringHelper.WriteToPtr(creditCardType, ref ptr, 10);
Marshal.WriteInt32(ptr, EMVContact); ptr = IntPtr.Add(ptr, 4);
DelphiShortStringHelper.WriteToPtr(applicationName, ref ptr, 50);
DelphiShortStringHelper.WriteToPtr(applicationIdentifier, ref ptr, 15);
DelphiShortStringHelper.WriteToPtr(reserved, ref ptr, 10);
return ret;
}
}
public ReturnStruct GetReturnStruct()
{
var ret = new ReturnStruct();
ret.i = 2;
ret.card = "1234";
ret.name = "test";
ret.responsecode = "mese";
ret.responsetext = "dork";
ret.approval = "Plerk";
ret.tranid = "pse";
ret.reference = "Ig";
ret.d = DateTime.UtcNow.ToOADate();
ret.transactionType = "cit";
ret.creditCardType = "t2";
ret.EMVContact = 0;
ret.applicationName = "mpp";
ret.applicationIdentifier = "nne";
ret.reserved = "12";
return ret;
}
public void SendFingerPrintResult()
{
// get the window to send struct
IntPtr receiverHandle = FindWindow("TReceiverMainForm", "ReceiverMainForm");
if (receiverHandle == IntPtr.Zero) return;
// Get the struct
ReturnStruct ret = GetReturnStruct();
IntPtr ptr = ret.ToPtr();
try
{
var cds = new COPYDATASTRUCT
{
dwData = IntPtr(2), // to identify the message contents
cbData = Marshal.SizeOf(ret),
lpData = ptr
};
SendMessageCopyData(receiverHandle, WM_COPYDATA, UIntPtr.Zero, ref cds);
}
finally
{
Marshal.FreeHGlobal(ptr);
}
}
}
class DelphiShortStringHelper
{
public static void WriteToPtr(string s, ref IntPtr ptr, byte maxChars = 255)
{
byte[] bytes = System.Text.Encoding.Default.GetBytes(s);
int strLen = Math.Min(bytes.Length, (int)maxChars);
Marshal.WriteByte(ptr, (byte)strLen);
ptr = IntPtr.Add(ptr, 1);
Marshal.Copy(bytes, 0, ptr, strLen);
ptr = IntPtr.Add(ptr, (int)maxChars);
}
}
}
解决方案
您的代码中有一些小错误:
你的定义
COPYDATASTRUCT
是缺失的[StructLayout]
。您的定义
SendMessage()
略有错误(wParam
需要是 aUIntPtr
而不是 aInt32
)。你没有释放你分配的任何内存
IntPtrAlloc()
。
现在,对于主要问题:
在将字符串编组为固定长度的字符数组时,您需要使用UnmanagedType.ByValTStr
而不是(请参阅结构中使用的字符串)。UnmanagedType.LPTStr
但是,更重要的是(基于您在评论中而不是在您的主要问题中提供的详细信息),Delphi 方面期望接收到的结构中的字符串以短字符串格式编码,这与原始字符数组略有不同:
ShortString的长度为 0 到 255 个单字节字符。虽然ShortString的长度可以动态变化,但它的内存是静态分配的 256 字节;第一个字节存储字符串的长度,其余 255 个字节可用于字符。If
S
是一个ShortString变量,Ord(S[0])
和 一样Length(S)
,返回 ; 的长度S
。给 赋值S[0]
,就像调用一样SetLength
,会改变 的长度S
。维护ShortString只是为了向后兼容。Delphi 语言支持短字符串类型——实际上是ShortString的子类型——其最大长度为 0 到 255 个字符。这些由附加到保留字字符串的括号内的数字表示。例如:
var MyString: string[100];
创建一个名为 的变量
MyString
,其最大长度为 100 个字符。这相当于声明:type CString = string[100]; var MyString: CString;
以这种方式声明的变量仅分配类型所需的内存 - 即指定的最大长度加上一个字节。在我们的示例中,
MyString
使用 101 个字节,而预定义ShortString类型的变量使用 256 个字节。将值分配给短字符串变量时,如果字符串超过该类型的最大长度,则会截断该字符串。
标准函数
High
和Low
对短字符串类型标识符和变量进行操作。High
返回短字符串类型的最大长度,同时Low
返回零。
因此,请尝试更多类似的方法:
[StructLayout(LayoutKind.Sequential)]
public struct COPYDATASTRUCT
{
public IntPtr dwData;
public int cbData;
public IntPtr lpData;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)]
public struct ReturnStruct
{
public int i;
public byte card_len;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 50)]
public string card;
public byte name_len;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 100)]
public string name;
public byte responsecode_len;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 5)]
public string responsecode;
public byte responsetext_len;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 100)]
public string responsetext;
public byte approval_len;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 15)]
public string approval;
public byte tranid_len;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 50)]
public string tranid;
public byte reference_len;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 16)]
public string reference;
public double d;
public byte transactionType_len;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 24)]
public string transactionType;
public byte creditCardType_len;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 10)]
public string creditCardType;
public int EMVContact;
public byte applicationName_len;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 50)]
public string applicationName;
public byte applicationIdentifier_len;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 15)]
public string applicationIdentifier;
public byte reserved_len;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 10)]
public string reserved;
}
public ReturnStruct GetReturnStruct()
{
var ret = new ReturnStruct();
ret.i = ...;
ret.card = ...;
ret.card_len = (byte) Math.Min(System.Text.Encoding.Default.GetByteCount(ret.card), 50);
ret.name = ...;
ret.name_len = (byte) Math.Min(System.Text.Encoding.Default.GetByteCount(ret.name), 100);
ret.responsecode = ...;
ret.responsecode_len = (byte) Math.Min(System.Text.Encoding.Default.GetByteCount(ret.responsecode), 5);
ret.responsetext = ...;
ret.responsetext_len = (byte) Math.Min(System.Text.Encoding.Default.GetByteCount(ret.responsetext), 100);
ret.approval = ...;
ret.approval_len = (byte) Math.Min(System.Text.Encoding.Default.GetByteCount(ret.approval), 15);
ret.tranid = ...;
ret.tranid_len = (byte) Math.Min(System.Text.Encoding.Default.GetByteCount(ret.tranid), 50);
ret.reference = ...;
ret.reference_len = (byte) Math.Min(System.Text.Encoding.Default.GetByteCount(ret.reference), 16);
ret.d = ...;
ret.transactionType = ...;
ret.transactionType_len = (byte) Math.Min(System.Text.Encoding.Default.GetByteCount(ret.transactionType), 24);
ret.creditCardType = ...;
ret.creditCardType_len = (byte) Math.Min(System.Text.Encoding.Default.GetByteCount(ret.creditCardType), 10);
ret.EMVContact = ...;
ret.applicationName = ...;
ret.applicationName_len = (byte) Math.Min(System.Text.Encoding.Default.GetByteCount(ret.applicationName), 50);
ret.applicationIdentifier = ...;
ret.applicationIdentifier_len = (byte) Math.Min(System.Text.Encoding.Default.GetByteCount(ret.applicationIdentifier), 15);
ret.reserved = ...;
ret.reserved_len = (byte) Math.Min(System.Text.Encoding.Default.GetByteCount(ret.reserved), 10);
return ret;
}
public static IntPtr IntPtrAlloc<T>(T param)
{
IntPtr retval = Marshal.AllocHGlobal(Marshal.SizeOf(param));
Marshal.StructureToPtr(param, retval, false);
return retval;
}
public static void IntPtrFree(ref IntPtr preAllocated)
{
Marshal.FreeHGlobal(preAllocated);
preAllocated = IntPtr.Zero;
}
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = false)]
public static extern int SendMessage(IntPtr hWnd, int uMsg, UIntPtr wParam, IntPtr lParam);
public void SendFingerPrintResult(string msg)
{
// get the window to send struct
IntPtr receiverHandle = GetWindow();
if (receiverHandle == IntPtr.Zero) return;
// Get the struct
ReturnStruct ret = GetReturnStruct();
IntPtr ptr = IntPtrAlloc(ret);
try
{
var cds = new COPYDATASTRUCT
{
dwData = IntPtr.Zero,
cbData = Marshal.SizeOf(ret),
lpData = ptr
};
IntPtr iPtr = IntPtrAlloc(cds);
try
{
SendMessage(receiverHandle, WM_COPYDATA, senderID, iPtr);
}
finally
{
IntPtrFree(ref iPtr);
}
}
finally
{
IntPtrFree(ref ptr);
}
}
您可以选择IntPtrAlloc()
通过调整SendMessage()
定义来删除内部调用(请参阅使用 SendMessage 的 C#,WM_COPYDATA 的问题):
[DllImport("user32.dll", CharSet = CharSet.Auto, EntryPoint = "SendMessage", SetLastError = false)]
public static extern int SendMessageCopyData(IntPtr hWnd, int uMsg, UIntPtr wParam, ref COPYDATASTRUCT lParam);
public void SendFingerPrintResult(string msg)
{
// get the window to send struct
IntPtr receiverHandle = GetWindow();
if (receiverHandle == IntPtr.Zero) return;
// Get the struct
ReturnStruct ret = GetReturnStruct();
IntPtr ptr = IntPtrAlloc(ret);
try
{
var cds = new COPYDATASTRUCT
{
dwData = IntPtr.Zero,
cbData = Marshal.SizeOf(ret),
lpData = ptr
};
SendMessageCopyData(receiverHandle, WM_COPYDATA, senderID, ref cds);
}
finally
{
IntPtrFree(ref ptr);
}
}
您还可以考虑编写自定义包装器来帮助编组 ShortString 值:
class DelphiShortStringHelper
{
public static void WriteToPtr(string s, ref IntPtr ptr, byte maxChars = 255)
{
byte[] bytes = System.Text.Encoding.Default.GetBytes(s);
int strLen = Math.Min(bytes.Length, (int)maxChars);
Marshal.WriteByte(ptr, (byte)strLen);
ptr = IntPtr.Add(ptr, 1);
Marshal.Copy(bytes, 0, ptr, strLen);
ptr = IntPtr.Add(ptr, (int)maxChars);
}
}
public struct ReturnStruct
{
public int i;
public string card;
public string name;
public string responsecode;
public string responsetext;
public string approval;
public string tranid;
public string reference;
public double d;
public string transactionType;
public string creditCardType;
public int EMVContact;
public string applicationName;
public string applicationIdentifier;
public string reserved;
public IntPtr ToPtr()
{
IntPtr ret = Marshal.AllocHGlobal(473);
IntPtr ptr = ret;
Marshal.WriteInt32(ptr, i); ptr = IntPtr.Add(ptr, 4);
DelphiShortStringHelper.WriteToPtr(card, ref ptr, 50);
DelphiShortStringHelper.WriteToPtr(name, ref ptr, 100);
DelphiShortStringHelper.WriteToPtr(responsecode, ref ptr, 5);
DelphiShortStringHelper.WriteToPtr(responsetext, ref ptr, 100);
DelphiShortStringHelper.WriteToPtr(approval, ref ptr, 15);
DelphiShortStringHelper.WriteToPtr(tranid, ref ptr, 50);
DelphiShortStringHelper.WriteToPtr(reference, ref ptr, 16);
Marshal.Copy(new double[]{d}, 0, ptr, 1); ptr = IntPtr.Add(ptr, 8);
DelphiShortStringHelper.WriteToPtr(transactionType, ref ptr, 24);
DelphiShortStringHelper.WriteToPtr(creditCardType, ref ptr, 10);
Marshal.WriteInt32(ptr, EMVContact); ptr = IntPtr.Add(ptr, 4);
DelphiShortStringHelper.WriteToPtr(applicationName, ref ptr, 50);
DelphiShortStringHelper.WriteToPtr(applicationIdentifier, ref ptr, 15);
DelphiShortStringHelper.WriteToPtr(reserved, ref ptr, 10);
return ret;
}
}
public ReturnStruct GetReturnStruct()
{
var ret = new ReturnStruct();
ret.i = ...;
ret.card = ...;
ret.name = ...;
ret.responsecode = ...;
ret.responsetext = ...;
ret.approval = ...;
ret.tranid = ...;
ret.reference = ...;
ret.d = ...;
ret.transactionType = ...;
ret.creditCardType = ...;
ret.EMVContact = ...;
ret.applicationName = ...;
ret.applicationIdentifier = ...;
ret.reserved = ...;
return ret;
}
public void SendFingerPrintResult(string msg)
{
// get the window to send struct
IntPtr receiverHandle = GetWindow();
if (receiverHandle == IntPtr.Zero) return;
// Get the struct
ReturnStruct ret = GetReturnStruct();
IntPtr ptr = ret.ToPtr();
try
{
...
}
finally
{
Marshal.FreeHGlobal(ptr);
}
}
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