"Willy Denoyette [MVP]" <willy.denoyette@telenet.be> wrote in message
news:OeqsHKjpIHA.3568@TK2MSFTNGP04.phx.gbl...
> "Cramer" <A@B.com> wrote in message
> news:upVDbjipIHA.3960@TK2MSFTNGP02.phx.gbl...
>> I'm wondering if there is an easy way to programmatically determine if an
>> assembly is installed in the GAC.
>>
>> This would be similar to our ability to easily determine if a file exists
>> (File.Exists(path)) - but for an assembly, of a particular version, etc
>> in the GAC.
>>
>> I have googled this and failed to find anything useful.
>>
>> Thanks
>>
>>
>
> You'll have to cal into the fusion API's (native code API's and COM).
> Here is a completes sample that illustrates how one can retrieve the path
> of an assembly in the GAC.
>
> // Note that this requires V2 of the framework!!!!.
> using System;
> using System.Runtime.InteropServices;
> using System.Text;
>
> namespace GacStuff
> {
> internal class GacApi
> {
> [DllImport("fusion.dll")]
> internal static extern IntPtr CreateAssemblyCache(
> out IAssemblyCache ppAsmCache,
> int reserved);
>
> }
> // GAC Interfaces - IAssemblyCache. As a sample, non used vtable
> entries declared as dummy.
> [ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown),
> Guid("e707dcde-d1cd-11d2-bab9-00c04f8eceae")]
> internal interface IAssemblyCache
> {
> int Dummy1();
> [PreserveSig()]
> IntPtr QueryAssemblyInfo(
> int flags,
> [MarshalAs(UnmanagedType.LPWStr)]
> String assemblyName,
> ref ASSEMBLY_INFO assemblyInfo);
> int Dummy2();
> int Dummy3();
> int Dummy4();
> }
> [StructLayout(LayoutKind.Sequential)]
> internal struct ASSEMBLY_INFO
> {
> public int cbAssemblyInfo;
> public int assemblyFlags;
> public long assemblySizeInKB;
> [MarshalAs(UnmanagedType.LPWStr)]
> public String currentAssemblyPath;
> public int cchBuf;
> }
>
> class Program
> {
> static void Main()
> {
> try
> {
> Console.WriteLine(QueryAssemblyInfo("System"));
> }
> catch(System.IO.FileNotFoundException e)
> {
> Console.WriteLine(e.Message);
> }
> }
> // If assemblyName is not fully qualified, a random matching may be
> returned!!!!
> public static String QueryAssemblyInfo(String assemblyName)
> {
> ASSEMBLY_INFO assembyInfo = new ASSEMBLY_INFO ();
> assembyInfo.cchBuf = 512;
> assembyInfo.currentAssemblyPath = new String('\0',
> assembyInfo.cchBuf) ;
> IAssemblyCache assemblyCache = null;
> // Get IAssemblyCache pointer
> IntPtr hr = GacApi.CreateAssemblyCache(out assemblyCache, 0);
> if (hr == IntPtr.Zero)
> {
> hr = assemblyCache.QueryAssemblyInfo(1, assemblyName, ref
> assembyInfo);
> if(hr != IntPtr.Zero)
> Marshal.ThrowExceptionForHR(hr.ToInt32());
> }
> else
> Marshal.ThrowExceptionForHR(hr.ToInt32());
> return assembyInfo.currentAssemblyPath;
> }
> }
> }
>
> Willy.
>
>

On Apr 24, 12:32=A0pm, "Cramer" <A...@B.com> wrote:
> I'm wondering if there is an easy way to programmatically determine if an
> assembly is installed in the GAC.
>
> This would be similar to our ability to easily determine if a file exists
> (File.Exists(path)) - but for an assembly, of a particular version, etc in=

> the GAC.
>
> I have googled this and failed to find anything useful.
>
> Thanks

> IT should be simple, first you need a reference to the assembly (you
> can use Assembly.GetAssembly(typeof( XXXX ) ); where XXXX is defined
> in that assembly)
> Then using Assembly.Location should be enough.

On Apr 24, 12:32 pm, "Cramer" <A...@B.com> wrote:
> I'm wondering if there is an easy way to programmatically determine if an
> assembly is installed in the GAC.
>
> This would be similar to our ability to easily determine if a file exists
> (File.Exists(path)) - but for an assembly, of a particular version, etc in
> the GAC.
>
> I have googled this and failed to find anything useful.
>
> Thanks

On Apr 24, 5:15 pm, "Cramer" <A...@B.com> wrote:
> RE:
>
> > IT should be simple, first you need a reference to the assembly (you
> > can use Assembly.GetAssembly(typeof( XXXX ) ); where XXXX is defined
> > in that assembly)
> > Then using Assembly.Location should be enough.
>
> I should have been more specific. I want to know if an assembly is
> installed in the GAC *before* attempting to load it. This would be akin to
> using File.Exists() before attempting to open a file.
>
> Your approach assumes that the assembly is already loaded, which it is not
> in my case. In my case I want to determine if an assembly of a particular
> version etc is in the GAC, then load it if it's there, or write the fact to
> a log if it's not in the GAC.
>
> -Cramer

"Cramer" <A@B.com> wrote in message
news:upVDbjipIHA.3960@TK2MSFTNGP02.phx.gbl...
> I'm wondering if there is an easy way to programmatically determine if an
> assembly is installed in the GAC.
>
> This would be similar to our ability to easily determine if a file exists
> (File.Exists(path)) - but for an assembly, of a particular version, etc in
> the GAC.
>
> I have googled this and failed to find anything useful.
>
> Thanks
>
>

On Apr 24, 12:32 pm, "Cramer" <A...@B.com> wrote:
> I'm wondering if there is an easy way to programmatically determine if an
> assembly is installed in the GAC.
>
> This would be similar to our ability to easily determine if a file exists
> (File.Exists(path)) - but for an assembly, of a particular version, etc in
> the GAC.
>
> I have googled this and failed to find anything useful.
>
> Thanks