没有UI调用时为什么CalledFromWrongThreadException？

Question

我有一个AsyncTask调用webservice方法并将返回的数据发送回主线程。此任务不会影响任何UI元素，但会在调用CalledFromWrongThreadException的行上抛出onResultSuccess。我有许多其他AsyncTask基本上以完全相同的方式工作，更改被调用的Web服务方法和参数等，但这是唯一失败的。有人发现可能是什么问题吗？ AsyncTask看起来像是：

public static class ClockOff extends AsyncTask<String, Void, Void> 
{

public OnAsyncResultClockOff onAsyncResultClockOff;
public void setOnResultListener(OnAsyncResultClockOff onAsyncResultClockOff) {
    if(onAsyncResultClockOff != null) {
        ResultClockOff = onAsyncResultClockOff;
    }
}

private static final String SOAP_ACTION = "http://tempuri.org/ClockOff";
private static final String METHOD_NAME = "ClockOff";
private static final String NAMESPACE = "http://tempuri.org/";
private static final String URL = GlobalFunction.URL;
@Override
protected Void doInBackground(String... strArgs) 
{
    try
    {
        SoapObject Request = new SoapObject(NAMESPACE, METHOD_NAME);
         Request.addProperty("Items", strArgs[0]);
         Request.addProperty("ID", strArgs[1]);

         SoapSerializationEnvelope soapEnvelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
         soapEnvelope.dotNet = true;
         soapEnvelope.setOutputSoapObject(Request);
         HttpTransportSE transport= new HttpTransportSE(URL);
         transport.call(SOAP_ACTION, soapEnvelope);
         SoapObject result = (SoapObject) soapEnvelope.bodyIn;

         String ReturnMessage = ((SoapObject) result.getProperty(0)).getPropertyAsString(0);
         String ReturnMessageHeader = ((SoapObject) result.getProperty(0)).getPropertyAsString(1);
         String ActionType = ((SoapObject) result.getProperty(0)).getPropertyAsString(2);
         String SelectedCompleted = ((SoapObject) result.getProperty(0)).getPropertyAsString(3);
         String ClockOffItems = ((SoapObject) result.getProperty(0)).getPropertyAsString(4);

         //Exception thrown on the below line
         onAsyncResultClockOffItem.onResultSuccess(ReturnMessage, ReturnMessageHeader, ActionType, SelectedCompleted, ClockOffItems);
         return null;
    }
    catch (Exception e) 
    {
        onAsyncResultClockOffItem.onResultFail();
        return null;
    }
}
}

OnAsyncResultClockOff只是：

public interface OnAsyncResultClockOff {
    public abstract void onResultFail();
    public abstract void onResultSuccess(String returnMessage,
            String returnMessageHeader, String actionType,
            String selectedCompleted, String clockOffItems);
}

通过以下方式调用：

ClockOff co= new ClockOffItem();
co.setOnResultListener(onAsyncResultClockOff);
co.execute(items, ID);

onAsyncResultClockOff实施OnResultFail()和OnResultSuccess方法。