C# - Can't Initialize A User Control Property Using Eval
Feb 23, 2010
I designed a user control. It contains a public property "CurrentValue". When I try to initialize the property using an Eval expression, a null value is assigned.
// In below code, label assignment is OK, RatingNull user control assignment get null
I have one ASP.Net web page dynamically loading any one of about twenty User Controls at a given time. Since each user control is somewhat different, I've implemented the following extension to me pass a variable number of parameters to custom user control constructors: [URL]It, by the way, works very well! However, I've now come across the fact that both the web page and the user controls will need to share a few Data Tables. In other words, both the web page and the user control will need to access and manipulate data in these data tables.
To implement this fact I've used the Session object to store each data table. Each of these data tables starts out empty and then starts growing as the user enters more data into the user controls. The initialization of the data tables has to be done in the web page for a series of technical reasons that I won't get into here but rest assured that it does have to occur there.
But I found that in order to ENSURE that the initialization was taking place, it was simplest to just pass a reference to each data table as an extra parameter in the LoadUserControl call. This does work but it seems like overkill to me because on the user control constructor side, nothing is actually done with the data tables at the time of instantiation of the user control.
This made me go back to basics, thinking, "Why include a parameter if you're not actually going to use it?" But yet, it does seem to be the most straightforward way to ensure the data table is initialized and stored in the Session object.
I've got a web site that has a master page and that master page (mpMaster that has a user control ucControl1) which has a sub user control (ucControl2), this user control has a property which accepts a value. Now, I have a page that uses the master page and on this page I have another user control (ucPageControl), I need to find a way of setting the value in ucControl2 from ucPageControl. Is this possible at all?
i built a user control and i want to make one of its properties as a must, that's mean if you not supply this control when you create the control the project won't be compile, just like if you omit the runat="server" property.
I created one web user control with property named "ReadonlyField" with boolean datatype. I am able to use in my web pages and now i wanted to add a description to that property so that i dont need to explain each time to my team member what is that property's intention.
I got following snippet in c# but didnt find any equivalent in vb.net and also not sure whether it will work or not.
[Description("My Description")] public int MyIntProperty { get {..} set {..} }
I have a user control with a WebDateTimeEdit server control on it (essentially a TextBox). I'd like to be able to set some of the server control's properties by way of the user control's markup or programatically. for example I have this defined on my user control:
[code]....
this blows up because WebDateTimeEdit1 is null.
is there any way I can make this happen? also can do I do this
myControl2 .Font.Size = FontUnit.Point(8);
where the Font property is read only on the server control?
I have a control that I want to be able to mark areas as editable. When a user enters a username and password, they can then edit these editable areas.One of the area to edit is the main content of the page. Since I want them to be able to edit this on every page, I have put the editable control into the master page, wrapped around the ContentPlaceHolder of the master page.I found out how to allow the parser to allow <prefix:tag></prefix:tag> rather than just ending it with />, but I can't figure out how to get the text within the tags to be accessible through something like a Text property. A prime example of this behavior is the Label control, where you can put <asp:Label>Hello!</asp:Label> and access Hello! through the .Text property in the code.
I have created a user custom control, and what I would like to do is to pass it the text value from a label where I can carry out some other processing.
I have a very simple user control with 5 radio buttons on it, and 3 properties (ID, RatingSetID, and Rating). On the initial load of the page they are on, the code acquires data and places the data into the 3 properties. However, when the submit button is clicked the page reloads and the 3 properties get reset to 0, they are in the !IsPostBack as well.
I have a custom user control UserProfileLink on which I have two basic string properties, UID and UserFullName which I would like to use in a template column in a DataGrid like this:
I get an error saying "The server tag is not well formed" which leads me to believe this type of binding isn't possible. Is there a way to do this, or is it impossible?
I have a web user control (ascx) that exposes an "ID" property. What I want to do is set this property when the SelectedIndexChanged event fires in a gridview in the containing page. However, I can't seem to do it.... Here's my code:
CustomControl.ascx <%@ Control Language="vb" CodeBehind="CustomControl.ascx.vb" %> <asp:Panel ID="myPanel" runat="server"></asp:Panel>
I'd lke to expose that panel as a property that I can use at design time.
CustomControl.ascx.vb <ParseChildren(True), PersistChildren(False)> _ Partial Public Class CustomControl Inherits System.Web.UI.UserControl #Region "Members and Properties" <PersistenceMode(PersistenceMode.InnerProperty)> _ Public Property SomePanel() As Panel Get Return myPanel End Get Set(ByVal value As Panel) myPanel= value End Set End Property #End Region Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load Response.Write(myPanel.HasControls.ToString()) End Sub End Class
Before I get to the question, let me give a bit of background. I'm trying to develop a custom caching mechanism that I can apply to custom built user controls. (Please be aware that I know that there are some built in caching mechanism in .NET) Depending on certain flags set declaratively in the mark-up the control should load a cached version of its previously rendered content or execute normally (and if certain flags are set it should generate a cache of its content for next time it loads). I would like to be able to pass certain flags declaratively in the mark-up and being able to check their value at Page Init and, depending on the flag value, determine whether the control should load a cached version or not.
The problem that I'm facing is that as far as I'm aware I can only get the value of the properties declaratively assigned in the mark-up if I called the DataBind(). However I'm faced with two problems: Firstly calling this.DataBind() from within MyUC will trigger the binding of all its child controls which would defeat the purpose of the cache; also all user controls have been built so that they will not call DataBind() before the LoadComplete event has fired, so to make sure that the parent controls they live in has done its initialisation and has computed the properties that are declaratively passed to the child user control (ie PropA, PropB, PropC).And now the question: is there a way to bind the CacheProp property so to retrieve its value without data binding all other properties and without triggering the data binding of all its child controls?
When I add a user control which has bindable properties to an asp.net page I do not see its bindable properties on the designer's dialog box when I click the edit Data bindings on the Repeater-Listview
Code: Imports System.ComponentModel <System.ComponentModel.DefaultBindingProperty("Text")> _ Public Class UserControls_ucSpecialTextBox Inherits System.Web.UI.UserControl ... <EditorBrowsable(EditorBrowsableState.Always), _
I'm having trouble to access a Parent's property in User Control. I don't know how to access the parent. The Parent Page's name is Search.aspx. I saw the example below and tried it:
[Code]....
Than I could access the Parent's Property, but when I ran the website I got these errors:
1. The user control is not declared in the parent page 2. The user contol has a circular reference
I have a hidden field on my default.aspx page. Within default.aspx page I have a user control which has a label on it. I need the label to display the value on the hidden field. How can I go about this?
