Custom Server Controls :: Custom Control's Children Do Not Persist Contents After Postback
Feb 25, 2011
I have created a really simple custom control to render panels into a page. The code is below. When I use my control and add any webcontrol to it, after each page postback the contents of these child controls vanishes.
I must have missed something really simple but run the example to reproduce this. Can anyone please enlighten me as to why the controls are being 'emptied' of their contents, and how I stop this occuring?
Now, How can I Parse it and render it in RenderContent method ? !!! The following method is always throw the first Exception, it means this.Controls is always empty !!! How can I do it and how I can access to the nested children in RenderControl method ?
public class Menu : WebControl { .... public override void RenderControl(HtmlTextWriter output) { if (!this.HasControls()) throw new Exception("Controls are empty"); .... } }
I am trying to persist data in a dynamically populated ListBox in a user control. Here are the details
I have a user control which contains a a listBox and button. On Page_Load of user control I am populating the ListBox control with some values. On Click of button, I am trying to fetch the values which I have selected in ListBox. Though this seems very simple and straight forward I am unable to fetch values.
I have placed brake point at Page_Load and on click function, I am seeing that the moment the breakpoint hits Page_Load function (before If (!Ispostback)) , listBox.SelectedIndex is becoming -1.
One more thing here is, I am placing this user control in an SharePoint application page to be specific checkin.aspx page . ( I know this should not be done, but that is the requirement for me)
I'm developing a custom server control, which, on its RenderContents method, does some fancy work and writes content to the page via the HtmTextWriter passed to the method. My code is something like this:
[Code]....
Now, I'd like to have a method to refresh the contents of the control (let's say, go to the db again). I was thinking of calling the RenderContents method manually. The thing is that I don't know how to get the HtmlTextWriter object that my page uses so that I can pass it to the method. How would I achieve this? Would that even work, or is there a better way to do it?
I am trying to build a custom composite control, which allows me to add custom content to each child control. It's a similar concept to what you have with a GridView and TemplateColumn. The markup used to place the control on the page would end up being something like this:
[Code]....
I have the code below, which allows me to put that markup on the page without throwing any errors, and it renders all the correct HTML, except it doesn't render the contents of the ColumnTemplate. I have replaced the Render() code with a comment because it's quite long winded and doesn't add anything important here:
[Code]....
I have tried to follow examples on MSDN and other forums but I can't make this work. I think I'm missing the code to render the contents of the template, but I don't know how to hook that up.
I have an object to hold some specific state information in my web application - I pass it back & forward between pages by making it a property of a basepage which works fine, but I lose it on postback.
Is there any way to persist this property without manually adding & reading it again from viewstate?
I want a create a custom/user control that has children.
For Example, I want my control to have the following markup:
<div runat="server" id="div"> <label runat="server" id="label"></label> <div class="field"> <!-- INSERT CHILDREN HERE --> </div> </div>
and when I want to use it on a page I simply:
<ctr:MyUserControl runat="server" ID="myControl"> <span>This is a child</span> <div runat="server" id="myChild">And another <b>child</b> </ctr:MyUserControl>
The child controls inside my user control will be inserted into my user control somewhere. What is the best way to accomplish this?
The functionality is similar to a asp:PlaceHolder but I want to add a couple more options as well as additional markup and the such. Also the child controls still need to be able to be accessed by the page. (in the example above the page should have the myChild Control on it)
EDIT ------
It can be a template control as long as it allows me to reference the children on the page.
I have a custom control which inherit from the Table class and in the constructor, it takes a an integer as an argument. There is no empty constructor.
Is there a way for the user to set that variable in the properties window after they drag the control onto a form.
I know some .NET controls, you can set the source for the parameter to different things like another control's property, QueryString using just the properties window.
Right now, I have to create the control dynamically. I read the query string and then created the object.
I've created loads of user controls, but this is my first time dealing with extending a server control. The problem I'm getting is that the base control's data is not being persisted across postbacks in a Master/Content page.I'm actually trying to get this working using a Telerik control (for my sins), but the same issue happens with a standard Web TextBox control. Code:
[Code]....
Now, I've copied the way I handle the control state as I do it with user controls (ControlState), and it isn't working. Can someone point me in the right direction please? All the examples I find refer to creating user controls, not extending existing controls. Specifically why nothing is being persisted on post back.
here's a situation and I would appreciate your response.
I have programmatically created the Wizard control:
Page_Load(obj s, evargs e) { Wizard ClaimDetailWizard = new Wizard(); foreach(int item in selectedItems) { //create new step //added custom control to new step //add step to wizard } //added wizard to a placeholder on a page }
Based on List I get from Session i added new steps to my wizard To each step I had added a custom control
Each custom control in tern contains another custom Gridview Control in it.
So here's the problem when the page loads for example for two steps. All is good Wizard does what it's supposed to do.
But when I try to use sorting or paging in that custom Gridview. Somehow it displays the gridview I should see in the next step of the wizard.
Also what I'm noticing through debugging. Is that when I press next in the wizard I go back to the original page where I do all of the code specified above, and it recreates the wizzard. But it goes to the next step. Is this the way wizard supposed to work? Just doesn't seem very efficient.
i am new to technology so go easy on this post according to what i read from web there are 3 type of custom server controls 1 superclass2 composite 3 renderedi found video tutorial for superclass custom server control but couldnt find video tutials for other 2.lease forward me link for composite and rendered custom server controls video tutorial
created a Custom Textbox Control that is intended to be a "masked date" textbox, so that I can handle different ways a user might enter in a date and make it work no matter what.I did this by creating a custom control with 3 separate Textboxes one for month,one for day one for year,then do some handling for different things that could be entered and it would all work.
The problem I am having is,when I add this control to the page,if I do an alert to check the Text value of the custom control it just gives me "[ServerControl1]" even if I enter in a date.
I tried doing an AutoPostback after entering so that it would refesh the Viewstate to have the values of the textboxes but the control doesnt seem to actually postback, even though I have it enabled.accessing the Textbox value after someoen has entered a date?first custom control I have created and have been using google.
I am creating custom server control. I have two classes in project. One is main class that render control and another will be used to render content based on condition.I just want to know how to render content from other classes in main class.For example. This isjust an example.My main class code
[Code]....
My TopLeftPane class
[Code]....
My page code on page load event
[Code]....
When I run the page, Header title always getting null. This is a just sample code. I will have more than 20 classes so I dont want to write a code in main class to render whole control.I hope all of you understand my problem.
I have to use inline code for an aspx page and I need to use a custom server control that is defined in the same aspx page but the control does not get processed as a server control. it gets returned as is as static html tag.
I'm getting some wierd behaviour with my User control. I've created User control & it has BUTTON which checks the validity of the number entered in the textbox of that user control. I have written Button Clik event handler in the USer Control code behind which checks the database table and tells valid or not. So far so good. In my application i dynamically add User controls. I make sure that I add them Page_Load so that for every postback UCs are visible. I'm ussing Session to save my UserControls. The problem starts at some point when i click the Validate button in the User Control all my user controls dissappear & after some postbacks all my controls appear. I don't know why this is happening. I have included my code for reference.
I'm building an n-tier application, with the web client and the class library separate. I'm also using the factory pattern of development, using interfaces to act as containers for different objects they are associated with. The problem I'm expreriencing is that I declared a public interface class in the class library and I can create an instance of it in in my aspx pages but whenever I declare it in my custom control code-side, i get an error, like so:
Error 20 The type or namespace name 'IContentMaker' could not be found (are you missing a using directive or an assembly reference?)
notge that I have inherited the class library namespace using the 'using' keyword just in case you are wondering. My code is like so:
using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Xml.Linq; using TQO_Classes ; //importing the class library project public partial class PageContentMgr : System.Web.UI.UserControl { private IContentMaker _data; //this line throws the error, it works fine on aspx pages
I have an ASP.net web application project written in VB. Am trying to test a cobbed-together "MyTreeview" control put together from C# code that's been converted.
I think this will come "close" to what I'm trying to do - just get a treenode to have a CSS tag and render properly.
I have an App_LocalResources directory and a file called CustomTreeNode.vb. Inside that file is the following code:
I have a Custom Server Control with a Collapsible Panel Extender. I want to be able to keep the Collapsable state (open or closed) when doing a Post Back.
Iam developing a custom checkbox control deriving from the 'compositecontrol' which i need to use it for a composite control purpose.
public class TngCheckBox : CompositeControl {
i have written the required properties which are working fine except the "checked" property. here is my code for 'checked' property. i tried both the below ways (commented one and not commneted) . the problem is the 'checked' value is not setting the value at the get set part of the property.its assigning the value at the design time , but when i check and uncheck its not updating the property value.which is resulting me wrong .
Iam developing a custom checkbox control deriving from the 'compositecontrol' which i need to use it for a composite control purpose.
public class TngCheckBox : CompositeControl {
i have written the required properties which are working fine except the "checked" property. here is my code for 'checked' property. i tried both the below ways (commented one and not commneted) . the problem is the 'checked' value is not setting the value at the get set part of the property.its assigning the value at the design time , but when i check and uncheck its not updating the property value.which is resulting me wrong .
I try to mak a custom textbox. Something pretty easy to do but I can't figure out one thing. When I write my textbox in designmode I have this <custom:Textbox runat="server" ID="Textbox1">Test</custom:Textbox> The problem is The textbox is a webcontrol I added to my class [Parsechildren(false)] like this [Parsechildren(false)]
public class Textbox : WebControl { }
now the problem is I want to able to write the Text from the textbox between the beginningtag and andingtag but I want to disable every other control in designmode. When I add < between the tags then you can see you can write all tags between it. disable all controls except literal between the tage in designmode?
