How to make unload for Assembly.LoadFrom method

Question

I'm working on a C# compact application with win CE platform and I am using this code .....

var assembly = Assembly.LoadFrom(assemblyFile);
Version ver = assembly.GetName().Version;
theVsertion = ver.ToString();

to get the file version but in another method, I must delete the old file, and when I try to use this code.

        if (File.Exists(assemblyFile))
        {
            File.Delete(assemblyFile);
        }

if found this error

" process cannot access the file ### because it is being used by another process."

please, anyone can help me with this issue.

score 1 · Answer 1 · answered Nov 04 '18 at 11:59

Just for the record: this is the solution to the problem. just replace the Assembly class with this code.

public static Version GetFileVersionCe(string fileName)
{
    int handle = 0;
    int length = GetFileVersionInfoSize(fileName, ref handle);
    Version v = null;
    if (length > 0)
    {
        IntPtr buffer = System.Runtime.InteropServices.Marshal.AllocHGlobal(length);
        if (GetFileVersionInfo(fileName, handle, length, buffer))
        {
            IntPtr fixedbuffer = IntPtr.Zero;
            int fixedlen = 0;
            if (VerQueryValue(buffer, "\\", ref fixedbuffer, ref fixedlen))
            {
                byte[] fixedversioninfo = new byte[fixedlen];
                System.Runtime.InteropServices.Marshal.Copy(fixedbuffer, fixedversioninfo, 0, fixedlen);
                v = new Version(
                    BitConverter.ToInt16(fixedversioninfo, 10), 
                    BitConverter.ToInt16(fixedversioninfo,  8), 
                    BitConverter.ToInt16(fixedversioninfo, 14),
                    BitConverter.ToInt16(fixedversioninfo, 12));
            }
        }
        Marshal.FreeHGlobal(buffer);
    }
    return v;
}

[DllImport("coredll", EntryPoint = "GetFileVersionInfo", SetLastError = true)]
private static extern bool GetFileVersionInfo(string filename, int handle, int len, IntPtr buffer);
[DllImport("coredll", EntryPoint = "GetFileVersionInfoSize", SetLastError = true)]
private static extern int GetFileVersionInfoSize(string filename, ref int handle);
[DllImport("coredll", EntryPoint = "VerQueryValue", SetLastError = true)]
private static extern bool VerQueryValue(IntPtr buffer, string subblock, ref IntPtr blockbuffer, ref int len);

score 0 · Accepted Answer · answered Nov 04 '18 at 10:42

0

The only way to unload an assembly is to unload the AppDomain. An alternative would be to read the file into a byte[] and load this byte[] as assembly.

answered Nov 04 '18 at 10:42

Klaus Gütter

11,151
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thank you, I already make a try for using AppDomain class but unfortunately, I am not using full .Net class, I am using compact .Net , so if you have a code sample please can you share it with me. – ahmed mohamady Nov 04 '18 at 11:25
Just found this [link](https://stackoverflow.com/questions/187999/how-do-i-get-the-version-of-an-assembly-without-loading-it) – Klaus Gütter Nov 04 '18 at 11:40
Unfortunately "GetAssemblyName" method not belong to compact .Net, – ahmed mohamady Nov 04 '18 at 11:46
Scroll down a bit on the referenced page, you will find GetFileVersionCe – Klaus Gütter Nov 04 '18 at 11:47

How to make unload for Assembly.LoadFrom method

2 Answers2