using System;
using System.Runtime.InteropServices;public struct Point
{
public int x;
public int y;
}class Example
{ static void Main()
{ // Create a point struct.
Point p;
p.x = 1;
p.y = 1; Console.WriteLine("The value of first point is " + p.x + " and " + p.y + "."); // Initialize unmanged memory to hold the struct.
IntPtr pnt = Marshal.AllocHGlobal(Marshal.SizeOf(p)); try
{ // Copy the struct to unmanaged memory.
Marshal.StructureToPtr(p, pnt, false); // Create another point.
Point anotherP; // Set this Point to the value of the
// Point in unmanaged memory.
anotherP = (Point)Marshal.PtrToStructure(pnt, typeof(Point)); Console.WriteLine("The value of new point is " + anotherP.x + " and " + anotherP.y + "."); }
finally
{
// Free the unmanaged memory.
Marshal.FreeHGlobal(pnt);
}
}} 这里,传入的Point要以结构体数组传入,请问应如何写?再次感谢
using System.Runtime.InteropServices;public struct Point
{
public int x;
public int y;
}class Example
{ static void Main()
{ // Create a point struct.
Point p;
p.x = 1;
p.y = 1; Console.WriteLine("The value of first point is " + p.x + " and " + p.y + "."); // Initialize unmanged memory to hold the struct.
IntPtr pnt = Marshal.AllocHGlobal(Marshal.SizeOf(p)); try
{ // Copy the struct to unmanaged memory.
Marshal.StructureToPtr(p, pnt, false); // Create another point.
Point anotherP; // Set this Point to the value of the
// Point in unmanaged memory.
anotherP = (Point)Marshal.PtrToStructure(pnt, typeof(Point)); Console.WriteLine("The value of new point is " + anotherP.x + " and " + anotherP.y + "."); }
finally
{
// Free the unmanaged memory.
Marshal.FreeHGlobal(pnt);
}
}} 这里,传入的Point要以结构体数组传入,请问应如何写?再次感谢
IntPtr ptr = Marshal.UnsafeAddrOfPinnedArrayElement ( p,0);
如果你要传递数组的话
我能想到的办法就是unsafe了
using System.Text;
using System.Runtime.InteropServices;public struct Point
{
public Int32 x, y;
}
public sealed class App
{
static void Main()
{
// Demonstrate the use of public static fields of the Marshal class.
Console.WriteLine("SystemDefaultCharSize={0}, SystemMaxDBCSCharSize={1}",
Marshal.SystemDefaultCharSize, Marshal.SystemMaxDBCSCharSize); // Demonstrate the use of the SizeOf method of the Marshal class.
Console.WriteLine("Number of bytes needed by a Point object: {0}",
Marshal.SizeOf(typeof(Point)));
Point p = new Point();
Console.WriteLine("Number of bytes needed by a Point object: {0}",
Marshal.SizeOf(p));
// Demonstrate how to call GlobalAlloc and
// GlobalFree using the Marshal class.
IntPtr hglobal = Marshal.AllocHGlobal(100);
Marshal.FreeHGlobal(hglobal); // Demonstrate how to use the Marshal class to get the Win32 error
// code when a Win32 method fails.
Boolean f = CloseHandle(new IntPtr(-1));
if (!f)
{
Console.WriteLine("CloseHandle call failed with an error code of: {0}",
Marshal.GetLastWin32Error());
}
} // This is a platform invoke prototype. SetLastError is true, which allows
// the GetLastWin32Error method of the Marshal class to work correctly.
[DllImport("Kernel32", ExactSpelling = true, SetLastError = true)]
static extern Boolean CloseHandle(IntPtr h);
}// This code produces the following output.
//
// SystemDefaultCharSize=2, SystemMaxDBCSCharSize=1
// Number of bytes needed by a Point object: 8
// Number of bytes needed by a Point object: 8
// CloseHandle call failed with an error code of: 6以上是MSDN中关于Marshal类的实例，希望对你有帮助。
int GetRegInfo( LPCSTR str_in_SERIAL_TYPE,LPCSTR str_in_SERIAL_PWLX ,LPCSTR str_in_Reg, int* i_out_recordcount ,gzyjpdf_reginfo* struct_out_reginfo )用是这样定义的:
unsafe public static extern int GetRegInfo(string str_SERIAL_TYPE, string str_SERIAL_PWLX, string str_Reg, int* out_recordcount,reginfo[] r1);结构体如下:
public struct reginfo
{
[MarshalAs(UnmanagedType.ByValTStr,SizeConst =13)]
public string c_SERIAL_REG; //批文编码
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 29)]
public string c_SERIAL_TYPE; //批文种类：1国产、2进口
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 157)]
public string c_SERIAL_PWLX; //批文类型代码
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 31)]
public string c_REG; //批文号
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 101)]
public string c_YPMC; //药品名称
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 201)]
public string c_ENGLISH; //英文名
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 101)]
public string c_TRADE_NAME; //商品名
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 156)]
public string c_FACTORY; //生产单位代码
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 156)]
public string c_SPEC; //规格代码 }程序调用如以下:
reginfo[] reginfo1 = new reginfo[10];
int intRetRows = 0;
int* pRetRows = &intRetRows;
int i111 = GetRegInfo("","","123", pRetRows, reginfo1 );
运行成功,但reginfo1没有值,在其他语言中是可以有值的.