C# 32位系统与64位系统调用不同的DLL文件

string dll32 = System.Windows.Forms.Application.StartupPath + @"\System.Data.SQLite-32.DLL";
            string dll64 = System.Windows.Forms.Application.StartupPath + @"\System.Data.SQLite-64.DLL";
            string dllpath = System.Windows.Forms.Application.StartupPath + @"\System.Data.SQLite.dll";
            string systemtype = string.Empty;
            systemtype = Detect32or64();
            if (systemtype == "32" || systemtype == string.Empty)
            {
                try
                {
                    using (FileStream fs = File.Create(dllpath)) {; }
                    File.Copy(dll32, dllpath, true);
                }
                catch
                {
                    ;
                }
            }
            else if (systemtype == "64")
            {
                try
                {
                    using (FileStream fs = File.Create(dllpath)) { }
                    File.Copy(dll64, dllpath, true);
                }
                catch
                {
                    ;
                }
            }

private static string Detect32or64()
        {
            switch (IntPtr.Size)
            {
                case 8:
                    return "64";
                default:
                    return "32";
            }
        }