kernel32.dll の CreateProcess 関数で遅延バインディングを使用しようとしていますが、他の関数とは異なり、null 値を返します。
遅延バインディングに使用しているコードは次のとおりです
public abstract class LateBinding
{
[DllImport("kernel32.dll", CharSet = CharSet.Auto, BestFitMapping = false, SetLastError = true), SuppressUnmanagedCodeSecurity()]
private static extern LBHandle LoadLibrary(string fileName);
[DllImport("kernel32.dll"), SuppressUnmanagedCodeSecurity()]
private static extern IntPtr GetProcAddress(LBHandle hModule, string procname);
private Delegate Result = default(Delegate);
public Delegate Call(string library, string method, Type type)
{
LBHandle Lib = LoadLibrary(library);
if (!Lib.IsInvalid && !Lib.IsClosed)
{
Result = Marshal.GetDelegateForFunctionPointer(GetProcAddress(Lib, method), type);
Lib.Close();
}
return Result;
}
}
[SecurityPermission(SecurityAction.LinkDemand, UnmanagedCode = true)]
public sealed class LBHandle : SafeHandleZeroOrMinusOneIsInvalid
{
[ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool FreeLibrary(IntPtr hModule);
private LBHandle() : base(true) { }
protected override bool ReleaseHandle()
{
return FreeLibrary(handle);
}
}
そして、これが関数を呼び出す方法です
private delegate bool dCreateProcess(string applicationName, string commandLine, IntPtr processAttributes, IntPtr threadAttributes, bool inheritHandles, uint creationFlags, IntPtr environment, string currentDirectory, ref STARTUP_INFORMATION startupInfo, ref PROCESS_INFORMATION processInformation);
dCreateProcess CreateProcess = Call("kernel32.dll", "CreateProcess", typeof(dCreateProcess)) as dCreateProcess;