I receive the following exception while attempting to log an error using Enterprise Library 5.0:
Activation error occured while trying to get instance of type LogWriter, key \"\""
Inner Exception Message 1:
"Resolution of the dependency failed,
type = \"Microsoft.Practices.EnterpriseLibrary.Logging.LogWriter\",
name = \"(none)\".
Inner Exception Message 2:
The type LogWriter cannot be constructed.
You must configure the container to supply this value."
Here’s the code:
public static void WriteException(Exception ex, string title)
{
try
{
LogEntry logEntry = new LogEntry()
{
Title = title,
Message = ex.Message,
Severity = TraceEventType.Error,
TimeStamp = DateTime.Now
};
Logger.Write(logEntry);
}
catch (Exception exception)
{
}
}
And here’s my Web.config:
<?xml version="1.0"?>
<!--
For more information on how to configure your ASP.NET application, please visit
http://go.microsoft.com/fwlink/?LinkId=169433
-->
<configuration>
<configSections>
<section name="loggingConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Logging.Configuration.LoggingSettings, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.505.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="true"/>
<section name="dataConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Data.Configuration.DatabaseSettings, Microsoft.Practices.EnterpriseLibrary.Data, Version=5.0.505.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="true"/>
</configSections>
<dataConfiguration defaultDatabase="OracleConnection">
<providerMappings>
<add databaseType="Microsoft.Practices.EnterpriseLibrary.Data.Oracle.OracleDatabase, Microsoft.Practices.EnterpriseLibrary.Data" name="Oracle.DataAccess.Client"/>
</providerMappings>
</dataConfiguration>
<connectionStrings>
<add name="PortalAdminContext" connectionString="Data Source=|DataDirectory|PortalAdmin.sdf" providerName="System.Data.SqlServerCe.4.0"/>
<add name="OracleConnection" connectionString="" providerName="Oracle.DataAccess.Client"/>
<add name="PersonalizationConnection" connectionString="" providerName="Oracle.DataAccess.Client"/>
</connectionStrings>
<system.web>
<compilation debug="true" targetFramework="4.0" />
<authentication mode="Forms">
<forms loginUrl="~/Account/Login.aspx" timeout="2880" />
</authentication>
<membership>
<providers>
<clear/>
<add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider" connectionStringName="ApplicationServices"
enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false"
maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10"
applicationName="/" />
</providers>
</membership>
<profile>
<providers>
<clear/>
<add name="AspNetSqlProfileProvider" type="System.Web.Profile.SqlProfileProvider" connectionStringName="ApplicationServices" applicationName="/"/>
</providers>
</profile>
<roleManager enabled="false">
<providers>
<clear/>
<add name="AspNetSqlRoleProvider" type="System.Web.Security.SqlRoleProvider" connectionStringName="ApplicationServices" applicationName="/" />
<add name="AspNetWindowsTokenRoleProvider" type="System.Web.Security.WindowsTokenRoleProvider" applicationName="/" />
</providers>
</roleManager>
</system.web>
<system.webServer>
<modules runAllManagedModulesForAllRequests="true"/>
</system.webServer>
<system.data>
<DbProviderFactories>
<remove invariant="System.Data.SqlServerCe.4.0"/>
<add name="Microsoft SQL Server Compact Data Provider 4.0" invariant="System.Data.SqlServerCe.4.0" description=".NET Framework Data Provider for Microsoft SQL Server Compact" type="System.Data.SqlServerCe.SqlCeProviderFactory, System.Data.SqlServerCe, Version=4.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"/>
</DbProviderFactories>
</system.data>
<loggingConfiguration name="" tracingEnabled="true" defaultCategory="General">
<listeners>
<add name="Event Log Listener"
type="Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.FormattedEventLogTraceListener, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.505.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
listenerDataType="Microsoft.Practices.EnterpriseLibrary.Logging.Configuration.FormattedEventLogTraceListenerData, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.505.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
source="PortalWebservice"
formatter="Text Formatter"
log="Portal"
machineName="."
traceOutputOptions="DateTime, Timestamp"
filter="All"/>
</listeners>
<formatters>
<add type="Microsoft.Practices.EnterpriseLibrary.Logging.Formatters.TextFormatter, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.505.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
template="Timestamp: {timestamp}{newline}
Message: {message}{newline}
Severity: {severity}{newline}
Title:{title}{newline}"
name="Text Formatter"/>
</formatters>
<categorySources>
<add switchValue="All" name="General">
<listeners>
<add name="Event Log Listener"/>
</listeners>
</add>
</categorySources>
<specialSources>
<allEvents switchValue="All" name="All Events">
<listeners>
<add name="Event Log Listener"/>
</listeners>
</allEvents>
<notProcessed switchValue="All" name="Unprocessed Category">
<listeners>
<add name="Event Log Listener"/>
</listeners>
</notProcessed>
<errors switchValue="All" name="Logging Errors & Warnings">
<listeners>
<add name="Event Log Listener"/>
</listeners>
</errors>
</specialSources>
</loggingConfiguration>
</configuration>
The “Portal” event log has been created.
This same code and same configuration work fine in other projects. However, I received the activation error in an ASP .Net Webservice, while attempting to log. It seems like it can’t find the Web.config when attempting to create the LogWriter.
I noticed that other projects started to experience the same “Activation Error” with the Database portion of Enterprise Library, and more investigation lead me to the machine.config for the .Net Framework 2.0 & 3.5. There was a common entry in machine.config and the project’s web.config for the Oracle Data Provider. Adding the entries that follow to web.config corrected the “Activation Errors” in the other projects and corrected the LogWriter Activation error in the project mentioned above: