Reflection and Generics.

[Rathish P S]

Hi friends,
I am trying with Reflection and Generics in C#. But I get
confused with some of these new features. I am trying to get the type
of generic parameter with the type.Assembly.G etType(name,fal se,false)
method. It is return as null. Can anybody tell can help me to find the
basic reason of this issue?
this is the sample code that I used.

using System;
using System.Collecti ons.Generic;
using System.Text;
using System.CodeDom. Compiler;
using System.Reflecti on;
using System.Diagnost ics;

namespace GenericReflecti onApp
{
class Program
{
static void Main(string[] args)
{
string assemblyPath = GetValidAssembl y(args);
assemblyPath = System.Environm ent.CurrentDire ctory;
assemblyPath = assemblyPath + @"\GenericsLib. dll";
Assembly GenericLibAssem bly = Assembly.LoadFr om(assemblyPath );
Type[] allType = GenericLibAssem bly.GetTypes();
foreach(Type type in allType)
{
if (type.IsGeneric Type)
{
MethodInfo[] methodInfo = type.GetMethods ();
foreach (MethodInfo mInfo in methodInfo)
{
CheckMethodPara metersType(mInf o);
CheckLocalVaria bleType(mInfo);
}
}
}
}

private static void CheckLocalVaria bleType(MethodI nfo mInfo)
{
if (mInfo.GetMetho dBody() != null)
{
IList<LocalVari ableInfo> localInfo =
mInfo.GetMethod Body().LocalVar iables;
foreach (LocalVariableI nfo lInfo in localInfo)
{
Type ltype = lInfo.LocalType ;
if (ltype.IsArray)
{
if (ltype.Contains GenericParamete rs)
{
Type arrayType = ltype.Assembly. GetType(ltype.N ame, false,
false);
Debug.Assert(ar rayType != null, "Generic Array Type Null (Local
Variable)");
}
else
{
Type arrayType = ltype.Assembly. GetType(ltype.F ullName, false,
false);
Debug.Assert(ar rayType != null, "Type Array Null (Local
Variable)");
}
}
}
}
}

private static void CheckMethodPara metersType(Meth odInfo mInfo)
{
ParameterInfo[] parameterInfo = mInfo.GetParame ters();
foreach (ParameterInfo pInfo in parameterInfo)
{
Type ptype = pInfo.Parameter Type;
if (ptype.IsArray)
{
if (ptype.Contains GenericParamete rs)
{
Type arrayType = ptype.Assembly. GetType(ptype.N ame, false,
false);
Debug.Assert(ar rayType != null, "Generic Array Type Null
(Parameter)");
}
else
{
Type arrayType = ptype.Assembly. GetType(ptype.F ullName, false,
false);
Debug.Assert(ar rayType != null, "Type Array Null (Parameter)");
}
}
}
}

private static string GetValidAssembl y(string[] sAssem)
{
string sAssemName;

if (0 == sAssem.Length)
{
// get this assembly
System.Diagnost ics.Process pr =
System.Diagnost ics.Process.Get CurrentProcess( );
sAssemName = pr.ProcessName + ".exe";
}
else
{
// it seems user has supplied some assembly name..ok take that
sAssemName = sAssem[0];
}

return sAssemName;
}
}
}
Thanks!
Rathish P S.

[Mattias Sjögren]

I am trying to get the type
of generic parameter with the type.Assembly.G etType(name,fal se,false)
method. It is return as null.

Why? You already have the parameter type in ptype. What's the point of
getting its name as a string and then turning it back into a Type?

If it's the array's generic element type you're after, use
ptype.GetElemen tType().
Mattias

--
Mattias Sjögren [MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
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