Loosely bound platform invocation for .NET.
Intended to remove the need for static classes when using P/Invoke. Supply an interface to the builder and get an implementation back.
- Mocking P/Invoke functions without manually writing a wrapper.
- Adding pre-call and post-call probing which allows exceptions for GetLastError() in the error handling pattern common in C libraries.
- Marshal attributes still work.
- Both 32-bit and 64-bit is supported.
- Unix support on Mono
- Implementation uses ILibrary, so you can even use libraries that implements extension functionality such as OpenGL or OpenAL.
- The default marshalling for strings is Ansi.
- Be aware that the Windows API postfix Ansi functions with A and Unicode with W.
using System;
using Platform.Invoke;
namespace Example
{
public interface IMessageBox
{
int MessageBox(IntPtr hWnd, string lpText, string lpCaption, uint uType);
}
public class Program
{
static void Main()
{
var msg = LibraryInterfaceFactory.Implement<IMessageBox>("user32", s => s + "A");
msg.MessageBox(IntPtr.Zero, "Hello World!", "Hello World!", 1);
}
}
}Notice the the second argument which appends "A" to all function call mappings in User32 in reference to the second issue.
using System;
using System.Reflection;
using Platform.Invoke;
using Platform.Invoke.Attributes;
namespace Example
{
public enum ErrorCode : uint
{
NoError = 0,
InvalidOperation = 0x0502,
}
[Library("opengl32")]
[EntryPointFormat("gl{0}")]
public interface IOpenGL
{
[SkipProbe] // Don't invoke probe actions on this method. It would cause infinite recursion.
ErrorCode GetError();
void ClearColor (float red, float green, float blue, float alpha);
}
public class Program
{
static void BeginCall(MethodInfo method, IOpenGL gl)
{
gl.GetError(); // Clear last error state
}
static void EndCall(MethodInfo method, IOpenGL gl)
{
var error = gl.GetError();
if(error == ErrorCode.InvalidOperation)
throw new InvalidOperationException();
}
private static void Main()
{
var opengl = LibraryInterfaceFactory.Implement<IOpenGL>(BeginCall, EndCall);
try
{
opengl.ClearColor(0, 0, 0, 1);
Console.WriteLine("Should have thrown InvalidOperationException since there is no context bound...");
}
catch (InvalidOperationException)
{
Console.WriteLine("Expected exception :D");
}
}
}
}