ASPxHiddenField.ClientInstanceName Property

Gets or sets the ASPxHiddenField‘s client programmatic identifier.

Namespace: DevExpress.Web

Assembly: DevExpress.Web.v23.2.dll

NuGet Package: DevExpress.Web

Declaration

C#

[DefaultValue("")]
public string ClientInstanceName { get; set; }

VB.NET

<DefaultValue("")>
Public Property ClientInstanceName As String

Property Value

Type	Default	Description
String	String.Empty	A string value that specifies the ASPxHiddenField‘s client identifier.

Remarks

Use the ClientInstanceName property to specify a unique client-side identifier for the ASPxHiddenField control. The ClientInstanceName property’s value can be used on the client side to programmatically access the client object rendered for the ASPxHiddenField control in client-side script. This property is particularly important in referencing the ASPxHiddenField control when it is contained within a naming container (for instance, within an ASPxPageControl‘s page or an ASPxPopupControl‘s window).

If the ClientInstanceName property is not specified for a control, the control’s client identifier is generated automatically, and equals the value of the control’s ID property. Note that in this case, client-side programmatic access to the control is not allowed when the control is contained within a naming container.

Special Characters in Client Instance Name

If the ClientInstanceName property contains special characters, for instance, the dot (.), you cannot access a client object by this name. Call the GetByName(name) method to retrieve the client-side object instead.

<dx:ASPxTextBox ... ClientInstanceName="SomeType.SomeProp" />

var txt = ASPxClientControl.GetControlCollection().GetByName("SomeType.SomeProp");  
txt.SetText("Some Text");  

Example

The following part of the ASPxHiddenField online demo illustrates how to manipulate the ASPxHiddenField items collection on the client and server side by using the ASPxClientHiddenField.Get, ASPxClientHiddenField.Set, ASPxHiddenField.Item property etc.

JS

...
var viewsCount = 3;
function ShowPrevPage(){
    ChangeActiveViewIndex(-1); 
}
function ShowNextPage(){
    ChangeActiveViewIndex(1);
}
function ChangeActiveViewIndex(changeIndex){
    hfAnswers.Set("questionIndex", GetQuestionIndex() + changeIndex);
    cpVoting.PerformCallback();
}
function GetQuestionIndex(){
    return hfAnswers.Get("questionIndex");
}
function IsPreviewPage(){
    return GetQuestionIndex() == (viewsCount - 1);
}
function OnSeasonChanged(s, e){
    hfAnswers.Set("month", 0);
    hfAnswers.Set("season", s.GetSelectedIndex());
}
function OnMonthChanged(s, e){
    hfAnswers.Set("month", s.GetSelectedIndex());
}
...

ASPX

<script runat="server">
...
     private void LoadPreview() {
         int seasonIndex = (int)hfAnswers["season"];
         int monthIndex = (int)hfAnswers["month"];
         lblSelectedSeason.Text = seasons[seasonIndex];
         lblSelectedMonth.Text = months[seasonIndex][monthIndex];
     }
...
 </script>

...
 <dxhf:ASPxHiddenField runat="server" ClientInstanceName="hfAnswers" ID="hfAnswers">
 </dxhf:ASPxHiddenField>
...