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authorBrad Payne (Vir Linden) <vir@lindenlab.com>2016-08-15 17:21:18 -0400
committerBrad Payne (Vir Linden) <vir@lindenlab.com>2016-08-15 17:21:18 -0400
commitf8f79c20ef8deeb7085894da09134e4663e61f4d (patch)
tree529d0d69220a378b5cca55f4160e40a35967fa43 /indra/tools/vstool/DispatchUtility.cs
parentab4a681034c0ca9fcadc9ac0f4fa3ca542d3422f (diff)
parentb0c434fadfb7085fa93d13b3f61f29d48c610834 (diff)
merge
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+#region Using Directives
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Runtime.InteropServices;
+using System.Reflection;
+using System.Security.Permissions;
+
+#endregion
+
+namespace TestDispatchUtility
+{
+ /// <summary>
+ /// Provides helper methods for working with COM IDispatch objects that have a registered type library.
+ /// </summary>
+ public static class DispatchUtility
+ {
+ #region Private Constants
+
+ private const int S_OK = 0; //From WinError.h
+ private const int LOCALE_SYSTEM_DEFAULT = 2 << 10; //From WinNT.h == 2048 == 0x800
+
+ #endregion
+
+ #region Public Methods
+
+ /// <summary>
+ /// Gets whether the specified object implements IDispatch.
+ /// </summary>
+ /// <param name="obj">An object to check.</param>
+ /// <returns>True if the object implements IDispatch. False otherwise.</returns>
+ public static bool ImplementsIDispatch(object obj)
+ {
+ bool result = obj is IDispatchInfo;
+ return result;
+ }
+
+ /// <summary>
+ /// Gets a Type that can be used with reflection.
+ /// </summary>
+ /// <param name="obj">An object that implements IDispatch.</param>
+ /// <param name="throwIfNotFound">Whether an exception should be thrown if a Type can't be obtained.</param>
+ /// <returns>A .NET Type that can be used with reflection.</returns>
+ /// <exception cref="InvalidCastException">If <paramref name="obj"/> doesn't implement IDispatch.</exception>
+ [SecurityPermission(SecurityAction.LinkDemand, Flags = SecurityPermissionFlag.UnmanagedCode)]
+ public static Type GetType(object obj, bool throwIfNotFound)
+ {
+ RequireReference(obj, "obj");
+ Type result = GetType((IDispatchInfo)obj, throwIfNotFound);
+ return result;
+ }
+
+ /// <summary>
+ /// Tries to get the DISPID for the requested member name.
+ /// </summary>
+ /// <param name="obj">An object that implements IDispatch.</param>
+ /// <param name="name">The name of a member to lookup.</param>
+ /// <param name="dispId">If the method returns true, this holds the DISPID on output.
+ /// If the method returns false, this value should be ignored.</param>
+ /// <returns>True if the member was found and resolved to a DISPID. False otherwise.</returns>
+ /// <exception cref="InvalidCastException">If <paramref name="obj"/> doesn't implement IDispatch.</exception>
+ [SecurityPermission(SecurityAction.LinkDemand, Flags = SecurityPermissionFlag.UnmanagedCode)]
+ public static bool TryGetDispId(object obj, string name, out int dispId)
+ {
+ RequireReference(obj, "obj");
+ bool result = TryGetDispId((IDispatchInfo)obj, name, out dispId);
+ return result;
+ }
+
+ /// <summary>
+ /// Invokes a member by DISPID.
+ /// </summary>
+ /// <param name="obj">An object that implements IDispatch.</param>
+ /// <param name="dispId">The DISPID of a member. This can be obtained using
+ /// <see cref="TryGetDispId(object, string, out int)"/>.</param>
+ /// <param name="args">The arguments to pass to the member.</param>
+ /// <returns>The member's return value.</returns>
+ /// <remarks>
+ /// This can invoke a method or a property get accessor.
+ /// </remarks>
+ public static object Invoke(object obj, int dispId, object[] args)
+ {
+ string memberName = "[DispId=" + dispId + "]";
+ object result = Invoke(obj, memberName, args);
+ return result;
+ }
+
+ /// <summary>
+ /// Invokes a member by name.
+ /// </summary>
+ /// <param name="obj">An object.</param>
+ /// <param name="memberName">The name of the member to invoke.</param>
+ /// <param name="args">The arguments to pass to the member.</param>
+ /// <returns>The member's return value.</returns>
+ /// <remarks>
+ /// This can invoke a method or a property get accessor.
+ /// </remarks>
+ public static object Invoke(object obj, string memberName, object[] args)
+ {
+ RequireReference(obj, "obj");
+ Type type = obj.GetType();
+ object result = type.InvokeMember(memberName, BindingFlags.InvokeMethod | BindingFlags.GetProperty,
+ null, obj, args, null);
+ return result;
+ }
+
+ #endregion
+
+ #region Private Methods
+
+ /// <summary>
+ /// Requires that the value is non-null.
+ /// </summary>
+ /// <typeparam name="T">The type of the value.</typeparam>
+ /// <param name="value">The value to check.</param>
+ /// <param name="name">The name of the value.</param>
+ private static void RequireReference<T>(T value, string name) where T : class
+ {
+ if (value == null)
+ {
+ throw new ArgumentNullException(name);
+ }
+ }
+
+ /// <summary>
+ /// Gets a Type that can be used with reflection.
+ /// </summary>
+ /// <param name="dispatch">An object that implements IDispatch.</param>
+ /// <param name="throwIfNotFound">Whether an exception should be thrown if a Type can't be obtained.</param>
+ /// <returns>A .NET Type that can be used with reflection.</returns>
+ private static Type GetType(IDispatchInfo dispatch, bool throwIfNotFound)
+ {
+ RequireReference(dispatch, "dispatch");
+
+ Type result = null;
+ int typeInfoCount;
+ int hr = dispatch.GetTypeInfoCount(out typeInfoCount);
+ if (hr == S_OK && typeInfoCount > 0)
+ {
+ // Type info isn't usually culture-aware for IDispatch, so we might as well pass
+ // the default locale instead of looking up the current thread's LCID each time
+ // (via CultureInfo.CurrentCulture.LCID).
+ dispatch.GetTypeInfo(0, LOCALE_SYSTEM_DEFAULT, out result);
+ }
+
+ if (result == null && throwIfNotFound)
+ {
+ // If the GetTypeInfoCount called failed, throw an exception for that.
+ Marshal.ThrowExceptionForHR(hr);
+
+ // Otherwise, throw the same exception that Type.GetType would throw.
+ throw new TypeLoadException();
+ }
+
+ return result;
+ }
+
+ /// <summary>
+ /// Tries to get the DISPID for the requested member name.
+ /// </summary>
+ /// <param name="dispatch">An object that implements IDispatch.</param>
+ /// <param name="name">The name of a member to lookup.</param>
+ /// <param name="dispId">If the method returns true, this holds the DISPID on output.
+ /// If the method returns false, this value should be ignored.</param>
+ /// <returns>True if the member was found and resolved to a DISPID. False otherwise.</returns>
+ private static bool TryGetDispId(IDispatchInfo dispatch, string name, out int dispId)
+ {
+ RequireReference(dispatch, "dispatch");
+ RequireReference(name, "name");
+
+ bool result = false;
+
+ // Members names aren't usually culture-aware for IDispatch, so we might as well
+ // pass the default locale instead of looking up the current thread's LCID each time
+ // (via CultureInfo.CurrentCulture.LCID).
+ Guid iidNull = Guid.Empty;
+ int hr = dispatch.GetDispId(ref iidNull, ref name, 1, LOCALE_SYSTEM_DEFAULT, out dispId);
+
+ const int DISP_E_UNKNOWNNAME = unchecked((int)0x80020006); //From WinError.h
+ const int DISPID_UNKNOWN = -1; //From OAIdl.idl
+ if (hr == S_OK)
+ {
+ result = true;
+ }
+ else if (hr == DISP_E_UNKNOWNNAME && dispId == DISPID_UNKNOWN)
+ {
+ // This is the only supported "error" case because it means IDispatch
+ // is saying it doesn't know the member we asked about.
+ result = false;
+ }
+ else
+ {
+ // The other documented result codes are all errors.
+ Marshal.ThrowExceptionForHR(hr);
+ }
+
+ return result;
+ }
+
+ #endregion
+
+ #region Private Interfaces
+
+ /// <summary>
+ /// A partial declaration of IDispatch used to lookup Type information and DISPIDs.
+ /// </summary>
+ /// <remarks>
+ /// This interface only declares the first three methods of IDispatch. It omits the
+ /// fourth method (Invoke) because there are already plenty of ways to do dynamic
+ /// invocation in .NET. But the first three methods provide dynamic type metadata
+ /// discovery, which .NET doesn't provide normally if you have a System.__ComObject
+ /// RCW instead of a strongly-typed RCW.
+ /// <para/>
+ /// Note: The original declaration of IDispatch is in OAIdl.idl.
+ /// </remarks>
+ [ComImport]
+ [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+ [Guid("00020400-0000-0000-C000-000000000046")]
+ private interface IDispatchInfo
+ {
+ /// <summary>
+ /// Gets the number of Types that the object provides (0 or 1).
+ /// </summary>
+ /// <param name="typeInfoCount">Returns 0 or 1 for the number of Types provided by <see cref="GetTypeInfo"/>.</param>
+ /// <remarks>
+ /// http://msdn.microsoft.com/en-us/library/da876d53-cb8a-465c-a43e-c0eb272e2a12(VS.85)
+ /// </remarks>
+ [PreserveSig]
+ int GetTypeInfoCount(out int typeInfoCount);
+
+ /// <summary>
+ /// Gets the Type information for an object if <see cref="GetTypeInfoCount"/> returned 1.
+ /// </summary>
+ /// <param name="typeInfoIndex">Must be 0.</param>
+ /// <param name="lcid">Typically, LOCALE_SYSTEM_DEFAULT (2048).</param>
+ /// <param name="typeInfo">Returns the object's Type information.</param>
+ /// <remarks>
+ /// http://msdn.microsoft.com/en-us/library/cc1ec9aa-6c40-4e70-819c-a7c6dd6b8c99(VS.85)
+ /// </remarks>
+ void GetTypeInfo(int typeInfoIndex, int lcid, [MarshalAs(UnmanagedType.CustomMarshaler,
+ MarshalTypeRef = typeof(System.Runtime.InteropServices.CustomMarshalers.TypeToTypeInfoMarshaler))] out Type typeInfo);
+
+ /// <summary>
+ /// Gets the DISPID of the specified member name.
+ /// </summary>
+ /// <param name="riid">Must be IID_NULL. Pass a copy of Guid.Empty.</param>
+ /// <param name="name">The name of the member to look up.</param>
+ /// <param name="nameCount">Must be 1.</param>
+ /// <param name="lcid">Typically, LOCALE_SYSTEM_DEFAULT (2048).</param>
+ /// <param name="dispId">If a member with the requested <paramref name="name"/>
+ /// is found, this returns its DISPID and the method's return value is 0.
+ /// If the method returns a non-zero value, then this parameter's output value is
+ /// undefined.</param>
+ /// <returns>Zero for success. Non-zero for failure.</returns>
+ /// <remarks>
+ /// http://msdn.microsoft.com/en-us/library/6f6cf233-3481-436e-8d6a-51f93bf91619(VS.85)
+ /// </remarks>
+ [PreserveSig]
+ int GetDispId(ref Guid riid, ref string name, int nameCount, int lcid, out int dispId);
+
+ // NOTE: The real IDispatch also has an Invoke method next, but we don't need it.
+ // We can invoke methods using .NET's Type.InvokeMember method with the special
+ // [DISPID=n] syntax for member "names", or we can get a .NET Type using GetTypeInfo
+ // and invoke methods on that through reflection.
+ // Type.InvokeMember: http://msdn.microsoft.com/en-us/library/de3dhzwy.aspx
+ }
+
+ #endregion
+ }
+}