调用Workday Assign_Costing_Allocation API时XML生成错误的排查与解决

Let’s break down how to debug this issue and fix that frustrating XML serialization error with Workday’s API. I’ve tackled similar problems with WCF and Workday integrations before, so here’s what works:

Debugging Steps to Identify the Root Cause #

• Enable XML Serialization Logging: Add this configuration to your app.config or web.config to capture detailed serialization logs. This will show exactly which type is causing the problem and where it’s being referenced:

  <configuration>
    <system.diagnostics>
      <sources>
        <source name="System.Xml.Serialization" switchValue="Information, ActivityTracing">
          <listeners>
            <add name="xml" type="System.Diagnostics.XmlWriterTraceListener" initializeData="serialization.log" />
          </listeners>
        </source>
      </sources>
    </system.diagnostics>
  </configuration>
  

  Check the generated serialization.log file for specific clues about where the type is being used unexpectedly.

• Inspect Your Request Object Structure: Double-check that you’re not passing a Tenanted_Payroll_WorktagObjectIDType instance where the API expects a base worktag type. Sometimes auto-generated proxies can have ambiguous inheritance hierarchies, so verify the type hierarchy in your References.cs file.

• Test with a Minimal Request: Build the smallest possible valid Assign_Costing_AllocationInput object (only required fields) and send it. Gradually add fields until the error reappears—this will pinpoint exactly which part of your request is triggering the serialization failure.

• Validate Against Workday’s Schema: Use the XSD from Workday’s API documentation to validate your request structure. Tools like Visual Studio’s XML Schema Validator can catch mismatches in type references that might be causing the error.

Fixes to Resolve the Serialization Error #

The core issue here is that the XML serializer doesn’t recognize Tenanted_Payroll_WorktagObjectIDType at runtime, even though it has serialization attributes. Here’s how to fix that:

1. Add XmlInclude to the Base Type:
   Find the parent class that Tenanted_Payroll_WorktagObjectIDType inherits from (e.g., WorktagObjectIDType in your proxy code) and add the XmlInclude attribute to it. This tells the serializer that the base type can include instances of this subclass:

   [System.Xml.Serialization.XmlInclude(typeof(Tenanted_Payroll_WorktagObjectIDType))]
   [System.CodeDom.Compiler.GeneratedCodeAttribute("System.Xml", "4.7.2612.0")]
   [System.SerializableAttribute()]
   public partial class WorktagObjectIDType : object, System.ComponentModel.INotifyPropertyChanged {
       // ... existing code ...
   }
   

2. Regenerate the Service Proxy:
   If you used Visual Studio’s "Add Service Reference" to generate the proxy, try regenerating it with these adjustments:

   • Open the "Advanced" settings during reference setup
   • Check "Reuse types in referenced assemblies" to ensure all related types are included
   • Confirm you’re using the correct v29.2 WSDL for Workday’s API—outdated WSDLs often cause missing type references

3. Add XmlInclude to the Service Contract:
   If the base type approach doesn’t work, add the XmlInclude attribute directly to your service interface or client class:

   [System.ServiceModel.ServiceContractAttribute(Namespace="urn:com.workday/bsvc", ConfigurationName="PayrollService.PayrollPort")]
   [System.Xml.Serialization.XmlInclude(typeof(Tenanted_Payroll_WorktagObjectIDType))]
   public interface PayrollPort {
       [System.ServiceModel.OperationContractAttribute(Action="urn:com.workday/bsvc/Assign_Costing_Allocation", ReplyAction="*")]
       Assign_Costing_AllocationResponse Assign_Costing_Allocation(Assign_Costing_AllocationInput request);
   }
   

4. Verify Serialization Attributes:
   Double-check that the Tenanted_Payroll_WorktagObjectIDType class has the correct XmlType attribute with the Workday namespace (urn:com.workday/bsvc). Your existing code shows it does, but auto-generated code can sometimes have typos—confirm the namespace matches exactly what the API expects.

内容的提问来源于stack exchange，提问作者jprusakova