Web服务未处理的异常

Question

To use webservice I added a web service reference and then added the following code to my MainPage.xaml.cs file.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Microsoft.Phone.Controls;

namespace WebServiceTest
{
  public partial class MainPage : PhoneApplicationPage
  {
    // Constructor
    public MainPage()
    {
      InitializeComponent();
    }

    private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)
    {
      try
      {
        ServiceReference.PDAServiceSoapClient ws = 
          new ServiceReference.PDAServiceSoapClient();
        ws.GetResoureAroudCompleted += 
          new EventHandler<ServiceReference.GetResoureAroudCompletedEventArgs>(ws_GetResoureAroudCompleted);

        ws.GetResoureAroudAsync("基站,机楼", 113, 23, 10000);
      }
      catch
      {
        System.Windows.MessageBox.Show("error！");
      }
    }

    void ws_GetResoureAroudCompleted(object sender, ServiceReference.GetResoureAroudCompletedEventArgs e)
    {
      if (e.Error != null)
      {
        var result = e.Result;
      }
    }
  }
}

Then I ran PhoneApplication and got this exception:

System.InvalidOperationException was unhandled Message=There was an error reflecting type 'WebServiceTest.ServiceReference.GetResoureAroudResponseGetResoureAroudResult'. InnerException: System.InvalidOperationException Message=There was an error reflecting property 'Any1'.

in Reference.cs Code:

public WebServiceTest.ServiceReference.GetResoureAroudResponseGetResoureAroudResult EndGetResoureAroud(System.IAsyncResult result) {
                object[] _args = new object[0];
                **WebServiceTest.ServiceReference.GetResoureAroudResponseGetResoureAroudResult _result = ((WebServiceTest.ServiceReference.GetResoureAroudResponseGetResoureAroudResult)(base.EndInvoke("GetResoureAroud", _args, result)));**
                return _result;
            }

It's not caught by try-catch, anybody know why?

Answer 1

I have faced the same problem and after investigating I did the following which solved the issue:

usually you will find two properties in the class causing the error:

private System.Xml.Linq.XElement[] anyField;

private System.Xml.Linq.XElement any1Field;

What I did was the following:

1- change the first property from an array to a single value variable as follows

private System.Xml.Linq.XElement anyField;

2- change the getter and setter methods of this property , to match your changes

[System.Xml.Serialization.XmlAnyElementAttribute(Namespace="http://www.w3.org/2001/XMLSchema", Order=0)]
public System.Xml.Linq.XElement Any {
    get {
        return this.anyField;
    }
    set {
        this.anyField = value;
        this.RaisePropertyChanged("Any");
    }
}

3- remove or comment out the second property

// private System.Xml.Linq.XElement any1Field;

4- remove or comment out the second property's getter and setter methods

/*   
[System.Xml.Serialization.XmlAnyElementAttribute(Namespace="urn:schemas-microsoft-com:xml-diffgram-v1", Order=1)] 
public System.Xml.Linq.XElement Any1 { 
    get { 
        return this.any1Field; 
    } 
    set { 
        this.any1Field = value; 
        this.RaisePropertyChanged("Any1"); 
    } 
}   
*/

At this point you can now access the resulting XML as follows by calling the "Any" property which will return an xml which you can manipulate :

ex, in my case it was the following class causing the problems

public partial class GetUserBalancesClassAccounts

in my method I was able to access the xml as follows

GetUserBalancesClassAccounts accts = balances.Accounts;

XElement doc = accts.Any;

foreach( XElement docElement in doc.Elements()){

    foreach (XElement account in docElement.Elements("Account"))   
    {

    ... do something ...

    }    
}

Answer 2

The exception is not caught by your exception handler because it occurs in the framework and is out of scope. Depending on whether the webservice conforms to best practice, it may surface an Error object and if so you should inspect this prior to attempting to retrieve any data.

This can produce symptoms similar to yours, but I'm not certain this is the problem you face.