Category Archives: ASP

HTML 5 ASP.NET Drag n Drop IE Chrome Firefox

25th November 2016 andre Leave a comment

drag and drop, cross browser support in asp.net

part of a project involved allowing a user to select from a list of 200+ items, and it needed to be easy. So, we decided to provide users with a drag and drop facility

Drag and drop has been around for quite some time, and its a little tricky to get it right. I’m going to show you the basics that i used to enable a drag and drop between lists

What are we after?

we want draggable lists that will do the following

Two lists
drag and drop
support multi select
support re order of list items

The end result

this is what the HTML will look like once the page has rendered, go ahead, give it a try. Try selecting multiple items then dragging them over

as you play around with the drag and drop, monitor your browser console to view the events that are firing

notice that when you change the selected fields the text area displays a comma separated list of selected items

Filter list

Choice fields

Name 1
Name 2
Name 3
Name 4
Name 5
Name 6
Name 7

Selected fields

Name 8
Name 9
Name 10
Name 11
Name 12
Name 13
Name 14

This drag and drop is tied together with just 4 javascript functions, tied to the browser drag events

handleStartDrag()
handleDragEnter()
handleDragOver()
handleDropped()

there are ancillary functions that bind events and respond to the filter

fltrChanged()
UpdatehiddenFields()
bindUIactions()

How its done

In a nutshell

The rendered HTML

<table>
	<tr>
		<td>Choice fields
		    <ul class="ctlDrop" id="lstleft" >
			<li class="ctlDrag" draggable="True" id="uniqueID1" data-fieldName="FieldName1"><span>Name 1</span></li>
			<li class="ctlDrag" draggable="True" id="uniqueID2" data-fieldName="FieldName2"><span>Name 2</span></li>
			<li class="ctlDrag" draggable="True" id="uniqueID3" data-fieldName="FieldName3"><span>Name 3</span></li>
			<li class="ctlDrag" draggable="True" id="uniqueID4" data-fieldName="FieldName4" ><span>Name 4</span></li>
			<li class="ctlDrag" draggable="True" id="uniqueID5" data-fieldName="FieldName5" ><span>Name 5</span></li>
			<li class="ctlDrag" draggable="True" id="uniqueID6" data-fieldName="FieldName6" ><span>Name 6</span></li>
			<li class="ctlDrag" draggable="True" id="uniqueID7" data-fieldName="FieldName7" ><span>Name 7</span></li>
		    </ul>
		</td>
		<td style="width: 4em;">&nbsp;</td>
		<td>Report fields
		    <ul class="ctlDrop" id="lstright">
			<li class="ctlDrag" draggable="True" id="uniqueID8" data-fieldName="FieldName8" ><span>Name 1</span></li>
			<li class="ctlDrag" draggable="True" id="uniqueID9" data-fieldName="FieldName9" ><span>Name 2</span></li>
			<li class="ctlDrag" draggable="True" id="uniqueID10" data-fieldName="FieldName10" ><span>Name 3</span></li>
			<li class="ctlDrag" draggable="True" id="uniqueID11" data-fieldName="FieldName11" ><span>Name 4</span></li>
			<li class="ctlDrag" draggable="True" id="uniqueID12" data-fieldName="FieldName12" ><span>Name 5</span></li>
			<li class="ctlDrag" draggable="True" id="uniqueID13" data-fieldName="FieldName13" ><span>Name 6</span></li>
			<li class="ctlDrag" draggable="True" id="uniqueID14" data-fieldName="FieldName14" ><span>Name 7</span></li>
		    </ul>
		</td>
	</tr>
	<tr>
		<td colspan="3">
			<input type="text" ID="hdnSelectedfields" />
		</td>
	</tr>
</table>

<table>

<tr>

<td>Choice fields

</ul>

</td>

<td>Report fields

</ul>

</td>

</tr>

<tr>

</td>

</tr>

</table>

So whats going on ?

Well a few things are happening here, CSS is styling our stuff. ASP.NET is loading the repeater and generating our “li” elements for the un-ordered lists. And jQuery is doing the rest

the keys points to note here are:

the classes used {ctlDrop, ctlDrag} (for CSS and more importantly jQuery hooks)
the draggable attribute on the items tell the browser these are allowed to be dragged
the use if ID‘s and Data- attributes as hooks for our functionality

how it works

first up i will say you have to do a few inexplicable things to get drag and drop working, but its a given, just do it and don’t ask, or you’ll simply lose your mind like many other techies who ask the “why did they do that?” question. like me

1. enable jQuery to support passing a payload across drag n drop.
2. declare a variable in your class to hold the last entered item that the drag action has entered.

    <!--Enable jQuery to support payload-->
    jQuery.event.props.push('dataTransfer');
    <!--class wide storage variable for the last entered item while dragging-->
    var curEnterElementID;

jQuery.event.props.push('dataTransfer');

var curEnterElementID;

The singleton script layout looks like this

jQuery(document).ready(function ($) {

    function ctlDragDrop() {
        "use strict";

        jQuery.event.props.push('dataTransfer');

        var curEnterElementID;

        function handleStartDrag(e) {        };
        function handleDropped(e) {        };
        function handleDragOver(e) {        };
        function handleFltrChanged(e){        };
        function handleDragEnter(e) {          };
        function UpdateHiddenFields() {        } ;

	this.bindUIactions = function () {         };

        <!--Public function initialise-->
        this.init = function () {
        };
    };

    ctlDragDrop = new ctlDragDrop();

    <!--initialise on a seperate thread-->
    setTimeout(function () { ctlDragDrop.init(); }, 0);  

});

jQuery(document).ready(function ($) {

function ctlDragDrop() {

"use strict";

jQuery.event.props.push('dataTransfer');

var curEnterElementID;

function handleStartDrag(e) { };

function handleDropped(e) { };

function handleDragOver(e) { };

function handleFltrChanged(e){ };

function handleDragEnter(e) { };

function UpdateHiddenFields() { } ;

this.bindUIactions = function () { };

this.init = function () {

};

ctlDragDrop = new ctlDragDrop();

setTimeout(function () { ctlDragDrop.init(); }, 0);

});

The Code

Loading the form

The code infront

jumping straight in, we need two lists, driven by some data source. Here is how we load the lists, using .net repeaters

<table>
    <tr>
	<td>Choice fields
	    <ul class="ctlDrop" id="lstleft" >
		<asp:Repeater ID="rptfieldsNotChoose" runat="server">
		    <ItemTemplate>
		    </ItemTemplate>
		</asp:Repeater>
	    </ul>
	</td>
	<td style="width: 4em;">&nbsp;</td>
	<td>Selected fields
	    <asp:HiddenField ID="hdnSelectedfields" runat="server" ClientIDMode="Static" />
	    <ul class="ctlDrop" id="lstright">
		<asp:Repeater ID="rptfieldsChosen" runat="server">
		    <ItemTemplate>
		    </ItemTemplate>
		</asp:Repeater>
	    </ul>
	</td>
    </tr>
</table>

<table>

<tr>

<td>Choice fields

<asp:Repeater ID="rptfieldsNotChoose" runat="server">

</ItemTemplate>

</asp:Repeater>

</ul>

</td>

<td>Selected fields

<asp:HiddenField ID="hdnSelectedfields" runat="server" ClientIDMode="Static" />

<asp:Repeater ID="rptfieldsChosen" runat="server">

</ItemTemplate>

</asp:Repeater>

</ul>

</td>

</tr>

</table>

Notice we have a hidden field in the right hand column, this will be used to stored the selected values, as the selection changes

Code Behind – the repeater code

On our data bind we add list items to the list, and some information to the each list item. Class, draggable, data-fieldName, data-ordinal.

Private Sub myPage_Init(sender As Object, e As EventArgs) Handles Me.Init
	AddHandler rptfieldsChosen.ItemDataBound, AddressOf repeater_ItemDataBound
	AddHandler rptfieldsNotChoose.ItemDataBound, AddressOf repeater_ItemDataBound
End Sub

Private Sub repeater_ItemDataBound(sender As Object, e As RepeaterItemEventArgs)
	If {ListItemType.AlternatingItem, ListItemType.Item}.Contains(e.Item.ItemType) Then
	    Dim di As Base.adoEntity.Model.vwlist_All_Field_Definitions = e.Item.DataItem
	    Dim li As New HtmlControls.HtmlGenericControl("li") With {.ID = di.GUID.ToString}
	    li.Attributes.Add("class", "ctlDrag")
	    li.Attributes.Add("data-ordinal", di.ordinal)
	    li.Attributes.Add("data-fieldName", di.column_name)
	    li.Attributes.Add("draggable", "True")
	    Dim span As New HtmlGenericControl("span")
	    span.InnerHtml = di.column_name
	    li.Controls.Add(span)
	    e.Item.Controls.Add(li)
	End If
End Sub

Private Sub myPage_Init(sender As Object, e As EventArgs) Handles Me.Init

AddHandler rptfieldsChosen.ItemDataBound, AddressOf repeater_ItemDataBound

AddHandler rptfieldsNotChoose.ItemDataBound, AddressOf repeater_ItemDataBound

End Sub

Private Sub repeater_ItemDataBound(sender As Object, e As RepeaterItemEventArgs)

If {ListItemType.AlternatingItem, ListItemType.Item}.Contains(e.Item.ItemType) Then

Dim di As Base.adoEntity.Model.vwlist_All_Field_Definitions = e.Item.DataItem

Dim li As New HtmlControls.HtmlGenericControl("li") With {.ID = di.GUID.ToString}

li.Attributes.Add("class", "ctlDrag")

li.Attributes.Add("data-ordinal", di.ordinal)

li.Attributes.Add("data-fieldName", di.column_name)

li.Attributes.Add("draggable", "True")

Dim span As New HtmlGenericControl("span")

span.InnerHtml = di.column_name

li.Controls.Add(span)

e.Item.Controls.Add(li)

End If

End Sub

jQuery – the ancillary functions

bindUIactions()

We will bind to the dragover and the drop event on the elements with class ctlDrop

We will bind to the dragstart, dragenter, drop and click events of the elements with class ctlDrag

Finally we will bind to the txtfltr element so we can filter our list

 this.bindUIactions = function () {
    <!--bind events-->
    $('.ctlDrop')
	.on("dragover", handleDragOver)
	.on("drop", handleDropped);

    $('.ctlDrag')
	.on("dragstart", handleStartDrag)
	.on("drop", handleDropped)
	.on("dragenter", handleDragEnter)
	.on("click", function (e) {
	    $(e.target).closest("li").toggleClass("selected");
	});
    $('#txtfltr').on("keyup blur change", handleFltrChanged);
};

this.bindUIactions = function () {

$('.ctlDrop')

.on("dragover", handleDragOver)

.on("drop", handleDropped);

$('.ctlDrag')

.on("dragstart", handleStartDrag)

.on("drop", handleDropped)

.on("dragenter", handleDragEnter)

.on("click", function (e) {

$(e.target).closest("li").toggleClass("selected");

});

$('#txtfltr').on("keyup blur change", handleFltrChanged);

};

UpdateHiddenFields()

handling the collecting of the selected items into a comma separated list is relatively simple, and this function will be called from the end of the drop event

function UpdateHiddenFields() {
    var hdn = $('#hdnSelectedfields');
    var flds = [];
    $("#lstright > li").each(function () {
	flds.push('[' +  $(this).attr("Data-fieldName") + ']')                
    });
    
    hdn.val(flds.join(","));
}

function UpdateHiddenFields() {

var hdn = $('#hdnSelectedfields');

var flds = [];

$("#lstright > li").each(function () {

flds.push('[' + $(this).attr("Data-fieldName") + ']')

});

hdn.val(flds.join(","));

}

jQuery – The Drag and Drop routines

handleStartDrag()

The start drag routine, a must have to set the sllowed effect property, this is searchable on the drop if you need to.

function handleStartDrag(e) {
    console.log("dragstart");

    e.dataTransfer.effectAllowed = 'move';
    e.dataTransfer.setData("text", e.target.id);
};

function handleStartDrag(e) {

console.log("dragstart");

e.dataTransfer.effectAllowed = 'move';

e.dataTransfer.setData("text", e.target.id);

};

handleDragOver()

The drag over routine, this is another must have, without this, obscurely no draggable item will drop. Don’t ask just do

function handleDragOver(e) {
    if (e.preventDefault) {
	e.preventDefault(); // Necessary. Allows us to drop.
    }
    e.dataTransfer.dropEffect = 'move';
    return false;
};

function handleDragOver(e) {

if (e.preventDefault) {

e.preventDefault(); // Necessary. Allows us to drop.

}

e.dataTransfer.dropEffect = 'move';

return false;

};

handleDragEnter()

The drag enter routine, this is required because internet explorer doesn’t correctly record which element the drop occurs over, so here we record the last entered element before the drop. And thus we have cross browser compatibility

function handleDragEnter(e) {
    console.log("enter " + $(e.currentTarget).prop("tagName") + ' ' + e.currentTarget.id);
    curEnterElementID = e.currentTarget.id;
};

function handleDragEnter(e) {

console.log("enter " + $(e.currentTarget).prop("tagName") + ' ' + e.currentTarget.id);

curEnterElementID = e.currentTarget.id;

};

handleDropped()

The drop routine, this is where all of the hard work is done. If you are a public facing website you might want to add screening of the mime type that is dropped, just incase its not what you are expecting. I’m not doing that here, our project was internal

function handleDropped(e) {
	console.log("drop " + $(e.currentTarget).prop("tagName") + ' ' + e.currentTarget.id);
	e.stopPropagation();
	e.preventDefault();

	var droppedElemID = e.dataTransfer.getData("text");
	var droppedElem = document.getElementById(droppedElemID);

	if (droppedElemID != undefined) {
		var ulTGT = $(e.target).closest(".ctlDrop")[0];
		var ulSRC = $('#' + droppedElemID).closest(".ctlDrop")[0];
		//how many selected items are there
		var currSelectedItems = $(ulSRC).find('li.selected');
		//get the index of the items, the source item and the item dropped over
		var indexofDropTGT = parseInt($('#' + ulTGT.id + ' li').index($('#'+ curEnterElementID).closest("li")[0]))
		var indexofDropSRC = parseInt($('#' + ulTGT.id + ' li').index($(droppedElem).closest("li")[0]))

		//For one way dropping uncomment this line
		//if (ulTGT.id === 'lstleft') { return false;}

		//if we are in the same drop object then we must be changing order
		if (ulSRC === ulTGT) {
			//if moving a selection around
			if (currSelectedItems.length > 1) {
				$(currSelectedItems).each(function (i, e) {
				    $($(ulTGT).children()[indexofDropTGT]).before(e);
				})
				$(ulTGT).find('li.selected').removeClass("selected");
			}
			else {
				//if moving a single item

				if (indexofDropSRC > indexofDropTGT) {
				    //moving down
				    $($(ulTGT).children()[indexofDropTGT]).before(droppedElem);
				}

				if (indexofDropSRC == 0 && indexofDropTGT == 0) {
				    //moving first or last
				    $($(ulTGT).children()[0]).before(droppedElem);
				}

				if (indexofDropSRC < indexofDropTGT) {
				    //moving up
				    $($(ulTGT).children()[indexofDropTGT]).after(droppedElem);
				}
			}

		}
		else {
			if (currSelectedItems.length > 1) {
				$(currSelectedItems).each(function (i, e) {
				    ulTGT.appendChild(e);
				    $('#' + e.id).closest("li").removeClass("selected");
				})
			}
			else {
				ulTGT.appendChild(droppedElem);
				$('#' + droppedElemID).closest("li").removeClass("selected");
			}
		}

	UpdateHiddenFields();
    }
};

function handleDropped(e) {

console.log("drop " + $(e.currentTarget).prop("tagName") + ' ' + e.currentTarget.id);

e.stopPropagation();

e.preventDefault();

var droppedElemID = e.dataTransfer.getData("text");

var droppedElem = document.getElementById(droppedElemID);

if (droppedElemID != undefined) {

var ulTGT = $(e.target).closest(".ctlDrop")[0];

var ulSRC = $('#' + droppedElemID).closest(".ctlDrop")[0];

//how many selected items are there

var currSelectedItems = $(ulSRC).find('li.selected');

//get the index of the items, the source item and the item dropped over

var indexofDropTGT = parseInt($('#' + ulTGT.id + ' li').index($('#'+ curEnterElementID).closest("li")[0]))

var indexofDropSRC = parseInt($('#' + ulTGT.id + ' li').index($(droppedElem).closest("li")[0]))

//For one way dropping uncomment this line

//if (ulTGT.id === 'lstleft') { return false;}

//if we are in the same drop object then we must be changing order

if (ulSRC === ulTGT) {

//if moving a selection around

if (currSelectedItems.length > 1) {

$(currSelectedItems).each(function (i, e) {

$($(ulTGT).children()[indexofDropTGT]).before(e);

})

$(ulTGT).find('li.selected').removeClass("selected");

}

else {

//if moving a single item

if (indexofDropSRC > indexofDropTGT) {

//moving down

$($(ulTGT).children()[indexofDropTGT]).before(droppedElem);

}

if (indexofDropSRC == 0 && indexofDropTGT == 0) {

//moving first or last

$($(ulTGT).children()[0]).before(droppedElem);

}

if (indexofDropSRC < indexofDropTGT) {

//moving up

$($(ulTGT).children()[indexofDropTGT]).after(droppedElem);

}

else {

if (currSelectedItems.length > 1) {

$(currSelectedItems).each(function (i, e) {

ulTGT.appendChild(e);

$('#' + e.id).closest("li").removeClass("selected");

})

}

else {

ulTGT.appendChild(droppedElem);

$('#' + droppedElemID).closest("li").removeClass("selected");

}

UpdateHiddenFields();

}

};

the javascript file is available for download here dragndrop

the CSS is available for download here dragndrop CSS

.NET, ASP, VB

String.replace ignorecase

3rd August 2011 andre 1 Comment

Replace a string but ignore the case, I keep forgetting about this little handy function

Heres an example of usage

'Import the library you need to use
Imports System.Text.RegularExpressions
'set up some vars here to play with
Dim TheString As String = "fint THAT String I need to change"
Dim ReplaceText As String = "the"
Dim TheResultsString As String

'INSTEAD OF THIS
TheResultsString = TheString.Replace("THAT", ReplaceText)
'DO THIS
TheResultsString = Regex.Replace(TheString, "that", ReplaceText, RegexOptions.IgnoreCase)

'Import the library you need to use

Imports System.Text.RegularExpressions

'set up some vars here to play with

Dim TheString As String = "fint THAT String I need to change"

Dim ReplaceText As String = "the"

Dim TheResultsString As String

'INSTEAD OF THIS

TheResultsString = TheString.Replace("THAT", ReplaceText)

'DO THIS

TheResultsString = Regex.Replace(TheString, "that", ReplaceText, RegexOptions.IgnoreCase)

Annoyances, ASP, Development

ASP.NET Master Page Nested inheritance

14th February 2011 andre Leave a comment

I seem to be asked this a lot so i thought i would mention this online so hopefully people will no longer ask me, they’ll find the answer when they ask google

You are trying to inherit from a masterpage and you recieve the following error

the page has one or more < asp:content> that do not correspond with < asp:ContentPlaceHolder> controls in masterpage

Script tags are the culprit around 80% of the time. For some reason the visual studio designer doesnt like not fully closing your script tags at design time.

Change all of you script tags from this

< script type="text/javascript" src="js/myjs.js" /> 
correcting it to this:
< script type="text/javascript" src="js/myjs.js" ><  /script>
Any you should be good to go.

.NET, ASP, Entity Framework 4.0, Linq, VB

VAT Information Exchange System (VIES)

7th December 2010 andre Leave a comment

What is the VIES ?
It is an electronic means of transmitting information relating to VAT-registration (= validity of VAT-numbers) of companies registered in EU. Furthermore, information relating to (tax exempt) intra-Community supplies between Member States’ administrations is also transmitted via VIES

The Taxation and Custom Union has provided us developers a nice little webservice to use for validating VAT numbers realtime.

This is their public facing page for one off manual validation
http://ec.europa.eu/taxation_customs/vies/
The service to be used by your application can be found here
http://ec.europa.eu/taxation_customs/vies/checkVatService.wsdl

The FAQ is here http://ec.europa.eu/taxation_customs/vies/faqvies.do

Ok so now i will demonstrate how to use this in your Visual Studio based application

If you have Visual Studio 2010, and your building a web app, in solution explorer right click the web app root node and you should see “Add Web Reference”, this will present you with the “Add Web Reference” dialog box
Paste the above web reference link into the “URL” and hit the “GO” green arrow

VIESVSWebReference — VIES Visual Studio Web Reference

Now Hit “Add Reference” and Visual Studio creates the Web Server Proxy and Wrapper Class.
Ok so now your project has the reference lets see how to use it

On your page that you wish to validate a vat number you should do the following
1. Collect a valid 2 character country code from the User
2. Collect a valid vat number from the User
3. Perform the needed filter on both of these values prior to envoking the webservice
4. Verify the return from the service and take action

First off you will need to import the reference into your page. For ease I use asp.net vb, C# will be similar and there are plenty of converters out there to see the code in c#

Imports eu.europa.ec

1	Imports eu.europa.ec

now your ready to use the reference
For this example we will be supplying country code and VAT number only. There are various other methods available but this suited me so its the only demo you will be getting.
The rules
1.The country code must be valid
2. The VAT number must contain no spaces and only be numerical numbers
3. We pass the validation boolean as a byref, if you also wanted to see what the company name and address the EU have on file for the company the webservice verified, you can pass two strings “Name” and “address” byref and view the content upon return.

This is how i do it

    ''' <summary>
    ''' Calls the Taxation Customs Union web service to validate the vat number
    ''' This works in most cases and is the best way to validate
    ''' VAT Information Exchange System (VIES)
    ''' </summary>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Function CheckVATEUNumber() As Boolean
        Dim IsValid As Boolean = False
        'get the country code of this User (they are logged in so we can find it)
        Dim Code As String = (From I In DLadoEntity.Items _
                             Join C In DLadoEntity.Countries On C.UID Equals I.CompanyCountryUID _
                             Join OC In DLadoEntity.OC_Locations On OC.UID Equals C.OCLocationUID _
                             Where I.UID = SC.intUserCompanyUID _
                             Select OC.ISO3166A2CountryCodes).FirstOrDefault

        'Prepare and clean up the VAT number supplied on the form
        Dim str As String = txtVatNumber.Text.Trim
        Dim vatnumber As String = ""
        For Each c As Char In str
            If IsNumeric(c) Then
                vatnumber = vatnumber & c
            End If
        Next

        'default to UK if we cant find a code
        If String.IsNullOrEmpty(Code) Then Code = "GB"

        'prepare our address and company name vars for return (we dont use them at the moment)
        Dim Add As String = "", Name As String = ""
        'encapsulate the webservice all in a try catch (if it fails in our case we dont worry very much)
        Try
            Dim ViesVATCheck As New eu.europa.ec.checkVatService
            ViesVATCheck.checkVat(Code, vatnumber, IsValid, Name, Add)
        Catch ex As Exception
            'if there is a problem validating the VAT number then we dont really care too much
            'we wont be buying anythingfrom them, they purchase from us so let let them through
            IsValid = True
        End Try

        Return IsValid
    End Function

''' <summary>

''' Calls the Taxation Customs Union web service to validate the vat number

''' This works in most cases and is the best way to validate

''' VAT Information Exchange System (VIES)

''' </summary>

''' <returns></returns>

''' <remarks></remarks>

Function CheckVATEUNumber() As Boolean

Dim IsValid As Boolean = False

'get the country code of this User (they are logged in so we can find it)

Dim Code As String = (From I In DLadoEntity.Items _

Join C In DLadoEntity.Countries On C.UID Equals I.CompanyCountryUID _

Join OC In DLadoEntity.OC_Locations On OC.UID Equals C.OCLocationUID _

Where I.UID = SC.intUserCompanyUID _

Select OC.ISO3166A2CountryCodes).FirstOrDefault

'Prepare and clean up the VAT number supplied on the form

Dim str As String = txtVatNumber.Text.Trim

Dim vatnumber As String = ""

For Each c As Char In str

If IsNumeric(c) Then

vatnumber = vatnumber & c

End If

'default to UK if we cant find a code

If String.IsNullOrEmpty(Code) Then Code = "GB"

'prepare our address and company name vars for return (we dont use them at the moment)

Dim Add As String = "", Name As String = ""

'encapsulate the webservice all in a try catch (if it fails in our case we dont worry very much)

Try

Dim ViesVATCheck As New eu.europa.ec.checkVatService

ViesVATCheck.checkVat(Code, vatnumber, IsValid, Name, Add)

Catch ex As Exception

'if there is a problem validating the VAT number then we dont really care too much

'we wont be buying anythingfrom them, they purchase from us so let let them through

IsValid = True

End Try

Return IsValid

End Function

Most of the above code is preparation, there are very few ines tha perform the webservice method.
The actual call is made in the try catch

Dim ViesVATCheck As New eu.europa.ec.checkVatService
ViesVATCheck.checkVat(Code, vatnumber, IsValid, Name, Add)

1 2	Dim ViesVATCheck As New eu.europa.ec.checkVatService ViesVATCheck.checkVat(Code, vatnumber, IsValid, Name, Add)

My particular app verifies the value of IsValid in the calling function, how you validate the values is up to you, on asuccessful return the value will be true and the byref Name and Add will contain the registered company name and address.

For your reference there is also another way to reference the web service described here http://softwareobjects.net/technology/other/vies-vat-number-checker/

Information Technology, Life, Interesting Stumbles, Servers, Configuration, Topology, Security, Best Practices, Developing, Fire Fighting, Problem solving, Visual Studio 2005 – 2015 .NET 1.1 – 4.5, jQuery, JSON & much much more