User Control's Default Property Values do Not Appear In Properties Window

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Jonathan Wood - 07 Feb 2008 16:33 GMT

Below is a user control (ascx file) I created.

Everything works fine except, when I first place an instance of the control
on a form and look at the associated properties, my initial property values
appear blank. They only show a value if I enter a new value.

What is the trick to have my default property values appear in the
properties window?

Thanks.

Signature

Jonathan Wood
SoftCircuits Programming
http://www.softcircuits.com

<%@ Control Language="C#" ClassName="HelpButton" %>

<script runat="server">

protected string _helpFile = "Help.aspx";
protected string _imageUrl = "Help.png";

public string HelpFile
{
get { return _helpFile; }
set { _helpFile = value; }
}

public string ImageURL
{
get { return _imageUrl; }
set { _imageUrl = value; }
}

protected void Page_Load(object sender, EventArgs e)
{
RegisterClientScripts();
}

protected override void Render(HtmlTextWriter writer)
{
base.Render(writer);

// Render control
writer.Write(String.Format("<input type=\"image\" src=\"{0}\" alt=\"Help\"
onclick=\"javascript:return ShowHelp('{1}');\" style=\"border-width:0px;\",
/>",
ResolveUrl("~/Images/Help.jpg"), ResolveUrl("~/Help/" + HelpFile)));
}

protected void RegisterClientScripts()
{
// Create client-side scripts to generate kilograms from pounds and vice
versa
if (!Page.ClientScript.IsClientScriptBlockRegistered("ShowHelp"))
{
Page.ClientScript.RegisterClientScriptBlock(typeof(Page), "ShowHelp",
"function ShowHelp(url){" +
"window.open(url, \"_blank\",
\"height=300,width=450,toolbar=no,status=no,menubar=no,location=no,scrollbars=yes\");"
+
"return false;}", true);
}
}

</script>

Reply to this Message

Manish - 07 Feb 2008 20:41 GMT

Hi Jonathan,

Please refer to the code below to create the CotnrolLibrary and then use it
in your App.

namespace WebControlLibrary1
{
    /// <summary>
    /// Summary description for WebCustomControl1.
    /// </summary>
    [DefaultProperty("Text"),
    ToolboxData("<{0}:PopupGreeting runat=server></{0}:PopupGreeting>")]
    public class PopupGreeting : System.Web.UI.Control
    {
        [Bindable(true),
        Category("Appearance"),
        DefaultValue("")]
        public string PopupMessage
        {
            get
            {
                // See if the item exists in the ViewState
                object popupMessage = this.ViewState["PopupMessage"];
                if (popupMessage != null)
                    return this.ViewState["PopupMessage"].ToString();
                else
                    return "Welcome to my Web site!";
            }

            set
            {
                // Assign the ViewState variable
                ViewState["PopupMessage"] = value;
            }
        }

        [Bindable(true),
        Category("Appearance"),
        DefaultValue("")]
        public bool Enabled
        {
            get
            {
                // See if the item exists in the ViewState
                object enabled = this.ViewState["Enabled"];
                if (enabled != null)
                    return (bool) this.ViewState["Enabled"];
                else
                    return true;
            }

            set
            {
                // Assign the ViewState variable
                ViewState["Enabled"] = value;
            }
        }

        protected override void OnPreRender(EventArgs e)
        {
            base.OnPreRender(e);

            string scriptKey = "intoPopupMessage:" + this.UniqueID;

            if (!Page.IsStartupScriptRegistered(scriptKey) && this.Enabled &&
                !Page.IsPostBack)
            {
                string scriptBlock =
                    @"<script language=""JavaScript"">

</script>";
                scriptBlock = scriptBlock.Replace("%%POPUP_MESSAGE%%", this.PopupMessage);

                Page.RegisterStartupScript(scriptKey, scriptBlock);
            }
        }
    }

}

Regards,
Manish
www.ComponentOne.com

> Below is a user control (ascx file) I created.
>
[quoted text clipped - 6 lines]
>
> Thanks.

Reply to this Message

Jonathan Wood - 08 Feb 2008 00:26 GMT

Okay, looks like I may be missing a few elements. I'll print out your post
and do a bit more studying.

Thanks.

Signature

Jonathan Wood
SoftCircuits Programming
http://www.softcircuits.com

> Hi Jonathan,
>
[quoted text clipped - 95 lines]
>>
>> Thanks.

Reply to this Message

User Control's Default Property Values do Not Appear In Properties Window

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