Postback does not reload all controls in the NameValueCollection

Question

Postback does not reload all controls in the NameValueCollection

Recently, I designed a custom User Control in asp.net.

public class InputMask : CompositeControl, IPostBackDataHandler, IPostBackEventHandler

Imagine the custom control is enclosed within a div element:

<div runat="server" id="inputArea">
    <asp:MaskInput runat="server" ID="ssn" ToolTip="SSN" Format="SSN" PartialMask="true" />
</div>

In the code behind, there is the following snippet:

 inputArea.Visible = False

During postback,

LoadPostData(string postDataKey, NameValueCollection postCollection)

does not contain the MaskInput key.

However, if you try this approach:

inputArea.Attributes.Add("style", "display:none")

The postCollection will have the MaskInput key present.

It seems that when using CSS to hide the div, the control is still rendered but invisible. On the other hand, with visible=false, the control is not even rendered at all.

Is there any workaround to retrieve the key in LoadPostData while using visible=false?

c#css asp.net custom-controls

Answer 1

Answer №1

To address and fix the issue at hand:

I made adjustments to the LoadPostData method as follows:

public override bool LoadPostData(string postDataKey, NameValueCollection postCollection) {
        this.Text = postCollection[ClientID + InputHiddenPostfix];
        return false;
    }

and updated it to:

public override bool LoadPostData(string postDataKey, NameValueCollection postCollection) {
        var key = ClientID + InputHiddenPostfix;
        string text = this.Text;
        if (postCollection.AllKeys.Any(k => k.Equals(key))) {
            string item = postCollection[key];
            if (this.ReadOnly || text.Equals(item, StringComparison.Ordinal)) {
                return false;
            }
            this.Text = item;
        } else {
            return false;
        }           
        return true;
    }

In addition, I modified the Text property to utilize ViewState

From:

    [Bindable(true)]
    [Category("Appearance")]
    [DefaultValue("")]
    public string Text { get; set; }

to

    [Localizable(true)]
    [PersistenceMode(PersistenceMode.EncodedInnerDefaultProperty)]
    [WebCategory("Appearance")]
    [WebSysDescription("MaskBase_Text")]
    [Bindable(true, BindingDirection.TwoWay)]
    [DefaultValue("")]
        public string Text {
        get {
            string item = (string)this.ViewState["Text"];
            if (item != null) {
                return item;
            }
            return string.Empty;
        }
        set {
            this.ViewState["Text"] = value;
        }
    }

Answer 2

To address and fix the issue at hand:

I made adjustments to the LoadPostData method as follows:

public override bool LoadPostData(string postDataKey, NameValueCollection postCollection) {
        this.Text = postCollection[ClientID + InputHiddenPostfix];
        return false;
    }

and updated it to:

public override bool LoadPostData(string postDataKey, NameValueCollection postCollection) {
        var key = ClientID + InputHiddenPostfix;
        string text = this.Text;
        if (postCollection.AllKeys.Any(k => k.Equals(key))) {
            string item = postCollection[key];
            if (this.ReadOnly || text.Equals(item, StringComparison.Ordinal)) {
                return false;
            }
            this.Text = item;
        } else {
            return false;
        }           
        return true;
    }

In addition, I modified the Text property to utilize ViewState

From:

    [Bindable(true)]
    [Category("Appearance")]
    [DefaultValue("")]
    public string Text { get; set; }

to

    [Localizable(true)]
    [PersistenceMode(PersistenceMode.EncodedInnerDefaultProperty)]
    [WebCategory("Appearance")]
    [WebSysDescription("MaskBase_Text")]
    [Bindable(true, BindingDirection.TwoWay)]
    [DefaultValue("")]
        public string Text {
        get {
            string item = (string)this.ViewState["Text"];
            if (item != null) {
                return item;
            }
            return string.Empty;
        }
        set {
            this.ViewState["Text"] = value;
        }
    }

Postback does not reload all controls in the NameValueCollection

Answer №1

Similar questions

Make the text in the SCSS file placeholder bold

Utilizing Inline Placement within Email Templates

Preventing background style from taking precedence over backgroundColor style in React's inline styling

Tips for downsizing a large image to fit into a smaller area

Avoid auto-scaling of div content

What's the name of the auto-triggered dropdown menu feature?

Add a new division to a component when a specific event handler is triggered by another component using React and the reduce method

Steps to animate a div expanding to fit its content dimensions

CSS Table columns are set to have a fixed width for the first and last columns, while the middle two columns have dynamic widths

ASP repeater exceeding container boundaries

Shifting Icon to the Right within the Drawer Navigator Toolbar

Why are the radio buttons not aligned with the text in the center?

The iPage server has encountered a 403 Forbidden Error, preventing

Here's a new take on the topic: "Implementing image change functionality for a specific div in Angular 8 using data from a loop"

What methods can be used to carry out personalized deserialization for specific fields?

Toggle jQuery to hide a div and update its CSS styling

Tips on changing textbox values in Page Object Model for both incrementing or decrementing

Verify whether a div element is styled in a specific manner

Tips for avoiding the display of the overall scrollbar while utilizing grid with an overflow:

Best Practices for Managing Long Running Tasks in ASP.NET 4.0 with C#