Error Configuring Services in an External Startup Class
When configuring services in an external startup class, there are a few common errors that developers encounter. Let’s discuss these errors in detail along with examples.
1. Class Not Found Error
This error occurs when the external startup class mentioned in the configuration is not found by the application.
Example:
<configuration>
<appSettings>
<add key="StartupClass" value="MyNamespace.MyExternalStartupClass" />
</appSettings>
</configuration>In the above example, if the “MyNamespace.MyExternalStartupClass” does not exist in the application, you will encounter a “Class Not Found” error.
2. Incorrect Class Name or Namespace
Make sure you provide the correct class name and namespace in the configuration. An incorrect class name or namespace will prevent the application from finding and executing the external startup class.
Example:
<configuration>
<appSettings>
<add key="StartupClass" value="InvalidNamespace.InvalidClass" />
</appSettings>
</configuration>In the above example, if the namespace “InvalidNamespace” or class name “InvalidClass” is incorrect, the external startup class will not be found, resulting in an error.
3. Assembly Loading Issues
When the external startup class is present in a different assembly other than the main application assembly, you need to ensure that the assembly is correctly referenced and loaded by the application.
Example:
<configuration>
<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
<dependentAssembly>
<assemblyIdentity name="ExternalAssembly" publicKeyToken="xxxxxxxxxxxx" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-999.999.999.999" newVersion="1.0.0.0" />
</dependentAssembly>
</assemblyBinding>
</runtime>
</configuration>In the above example, the application needs to reference and load the “ExternalAssembly” correctly. Ensure that the publicKeyToken and version are provided correctly to match the external assembly.
By analyzing these common errors, you should be able to troubleshoot and fix any issues you encounter when configuring services in an external startup class.