Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
?
Solved

return value async webservice

Posted on 2014-12-11
9
Medium Priority
?
142 Views
Last Modified: 2015-01-16
Does anyone have a good example of calling a web service asynchronously and retrieving a return value (i.e. a dataset) in ASP.NET And VB.NET ?
0
Comment
Question by:cehrnow
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 5
  • 4
9 Comments
 
LVL 96

Expert Comment

by:Bob Learned
ID: 40496641
Introductory questions:

What type of web service?

What type of web site?

Framework version?
0
 

Author Comment

by:cehrnow
ID: 40496856
ASMX
Framework 4.0
0
 
LVL 96

Expert Comment

by:Bob Learned
ID: 40497306
If you are going against a classic .asmx web service, then it should have auto-generated async methods in the proxy that it generated, so you could do something like this:

 	 Private supplier As New BookSupplier.WebService()

        Public Sub GetBookCost(ByVal bookName As String)

	   AddHandler supplier.GetCostCompleted AddressOf supplier_GetCostCompleted

	   supplier.GetCostAsync(bookName)

        End Sub

       Private Sub supplier1_GetCostCompleted(sender As Object, e As BookSupplier.GetCostCompletedEventArgs)
	   If e.Error IsNot Nothing Then
		Throw e.Error
	   End If
    	   Dim cost As Decimal = TryCast(e.UserState, Decimal)
	   costLabel.Text = "Quote from Book Supplier: " & cost
        End Sub

Open in new window

0
Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 

Author Comment

by:cehrnow
ID: 40497670
They did not get auto generated as I think this is not longer the default.
Can you please show what I need to add.
0
 
LVL 96

Expert Comment

by:Bob Learned
ID: 40500413
Can you show me the code for the auto-generated proxy?

How did you add the web service reference?
0
 

Author Comment

by:cehrnow
ID: 40500642
I don't think VS2013 adds these anymore ?
0
 
LVL 96

Expert Comment

by:Bob Learned
ID: 40501021
Here is an example of a classic web service reference:

     public void EchoMessageServiceAsync(string MessageID, string Destination, string Touchpoint, string Location, string Style, string ProductionFlag) {
            this.EchoMessageServiceAsync(MessageID, Destination, Touchpoint, Location, Style, ProductionFlag, null);
        }
       
        /// <remarks/>
        public void EchoMessageServiceAsync(string MessageID, string Destination, string Touchpoint, string Location, string Style, string ProductionFlag, object userState) {
            if ((this.EchoMessageServiceOperationCompleted == null)) {
                this.EchoMessageServiceOperationCompleted = new System.Threading.SendOrPostCallback(this.OnEchoMessageServiceOperationCompleted);
            }

Use the following steps:

Right click on the Reference node in the Server Explorer tree
Select Add Service Reference
Click on the Advanced button in the lower left corner
Click on the Add Web Reference button in the Compatibility section at the bottom of the Advanced dialog

This will allow you to add a web service reference the old, classic way.
0
 

Author Comment

by:cehrnow
ID: 40502155
It is the async methods in the webservice that are not being created.
Do you have VB code to show how these can be added ?
0
 
LVL 96

Accepted Solution

by:
Bob Learned earned 2000 total points
ID: 40503006
Even in Visual Basic, the async methods should be created when you add a classic web reference, using the Compatibility dialog.

I have uploaded a short .mp4 recording of what I mean.

https://filedb.experts-exchange.com/incoming/ee-stuff/8399-Add-Classic-Web-Reference.mp4
0

Featured Post

Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Article by: jpaulino
XML Literals are a great way to handle XML files and the community doesn’t use it as much as it should.  An XML Literal is like a String (http://msdn.microsoft.com/en-us/library/system.string.aspx) Literal, only instead of starting and ending with w…
It was really hard time for me to get the understanding of Delegates in C#. I went through many websites and articles but I found them very clumsy. After going through those sites, I noted down the points in a easy way so here I am sharing that unde…
In this video you will find out how to export Office 365 mailboxes using the built in eDiscovery tool. Bear in mind that although this method might be useful in some cases, using PST files as Office 365 backup is troublesome in a long run (more on t…
In this video, Percona Solution Engineer Rick Golba discuss how (and why) you implement high availability in a database environment. To discuss how Percona Consulting can help with your design and architecture needs for your database and infrastr…
Suggested Courses

636 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question