C# - Silverlight - Dynamically Creating Controls Without Any Postbacks?
Sep 27, 2010
Can I dynamically create controls in Silverlight without a postback to the server (even an asynchronous one). Does silverlight drag-n-drop requires postback?
I'm asking this because I've an asp.net application where I dynamically create/delete lots of controls. So after the postback I'm getting error with view state stating that the control tree doesn't match the view state tree.
On a dashboard page I'm loading several controls dynamically; the controls always need to be loaded so there is no if (!Page.IsPostBack) code. The problem though is in that in the code-behind, we are using Request.Form.GetValues and a particular dropdown field's value is always null (presumably because the controls are being cleared and reloaded on a postback) and this is triggering an error later on in the page that expectes a value from this dropdown. I have to use Request.Form.GetValues because the page enables dynamically adding rows (each row containing 5+ HTML inputs) via Javascript.
If I check for postback, then the button event of the control does not fire at all but instead the dashboard page is reloaded, and no controls are loaded at all (i.e. the page is blank).
How do I get around this issue? I need to dynamically load the controls at all times, but I also need to retrieve the values via Request.Form.GetValues.
(Server-side, in ibtnGetQuote_Click - this is actually a loop since user can append multiple rows; "i" is appended to the word "Class" to find the exact row)
IList<string> classes = this.GetFormValues("Class1"); // This will return null all the time... private IList<string> GetFormValues(string clientID) { String[] values; values = Request.Form.GetValues(clientID); if (values == null) { Control ctl = FindControl(clientID); // uses built-in FindControl method values = Request.Form.GetValues(ctl.ClientID);......
The original code was hardcoding the "ctl00$xx$xx" stuff, but the control may or may not be loaded so we cannot guarantee the name the control will get. In fact, I'm not even sure if this will work for all scenarios since only the FIRST control is a server control, the rest are just standard HTML controls so wouldn't have a "ClientID".
I have a C# web application that dynamically adds user controls to the default page for whatever "mode" the application is in. The problem is that it is not persisting these across postbacks. How do I persist these across postbacks and keep the content of the controls that are in the user control?
For instance, say I have a user control that creates a new tour record. The user clicks on the Tour item from the menu on the default page, it dynamically loads the tours user control. The user then fills out the form in the tours user control and clicks save. This is where the problem happens. When the postback occurs, the web application has no idea that the new tours user control was ever loaded. So, no save takes place because the Save button's click event never even gets fired.
i am currently working on a webform that has several dynamically populated dropdown lists. this works just fine, however, i have other web controls that require to have a postback..and at the time the page postsback, it reloads my dropdownlists, reseting whatever option i had chosen...
I'm trying to create an visual designer like Visual Studio, Expression Blend, Dreamweaver etc as an ONLINE APPLICATION (ASP.NET).
Can Silverlight be helpful with this? What are the things i need to be aware of before starting developing this online app? How good is it dragging, dropping & moving controls around with Silverlight?
I have added some combobox and texboxes in gridview dynamically to provide the data entry like operations.i have fetched and reset the value of these dynamically added controls on button click as ->
I have a GridView with a column of checkboxes. I also have a panel pnlSubmitOffer which serves as a modal dialog with ajaxToolkit:ModalPopupExtender:
[Code]....
I need a set of controls (text boxes and datetimepickers) to appear on the modal dialog based on how many checkboxes in the GridView are checked, i.e. a set for each checked record. Thus the controls should be added to the panel dynamically. But I don't know how to do it, as btnSubmitOffer click is not handled, because the modal dialog appears first. I was told that the controls can be added dynamically using javascript, but my knowledge of it is not enough.
I have a requirement in which i want to create an aspx form in which I want to define the name of the controls in the xml file and on the basis of the xml file i want to create the aspx form. if in the xml form there are 10 controls then dynamically 10 controls will be created i have following type of xml
I have a dropdown list on my homepage which users select a category. After selecting the category, user will fill a form which has related controls to that category in it.
As I have many categories, I just want to have single ascx page and adding controls to it dynamically according to the user choice.
For example: One chose Telephone category, he will face a form having drop down lists asking, what brand? what color? And one chose, book category, he will face drop down lists asking which type? howmany pages?
So 1 ascx must do my work at runtime done as I have alot of categories.
I am going to take these criterias from a database table which has CategoryID and Criteria colomns.
And if I can do that, will it be possible to add field validators to these dynamically created controls.
Never really worked with the asp tables but for this project it makes more sense, I am having trouble addding rows dynamically from the sql datatable i am pulling. In hte datatable it has 12 rows with 14 columns, I need to make this into a table, with a dtagrid I would be done but I have to pull other data that they could add columns, so a table I am told is easier.
This gets my data and I can see it
mydataTable = new DataTable mydataTable = GetData(sql) mydataTable.add.row(myDataTable.rows(0)(0))
I get nothing but errors trying to do this, what is the correct way to add rows to an asp.net table
Can I add this all to a datagrid and then add the extra columns I need if they are there with out using a table.
It seems when I try to dynamically create multiple instances of a User Control, I get an Object Reference Not Set To An Instance Of An Object error on any ASP control that I'm using in that User Control
Here's the class where I'm creating them.
[Code]....
Am I able to successfully refer to a panel on the page that I'm calling this routine from simply by ByVal ... As Panel, or should I use HttpContext?
I have created a control with two standard asp controls in (a label and a Textbox).I want to have access to the controls within but also be available from the designer so that the label properties can be prefixed with Label_ etc for example
[Code]....
How can I create a property from this reflection list?
apologies beforehand for what can possibly be a daft conceptual question. I have an ascx control that has a bunch of ASP labels and buttons in the ascx page and some other public methods and properties in the code behind. When I drop this ascx control in a page it all works fine. I now have a page with a placeholder and I am trying to dynamically create an instance of my ascx control and put it there. I then reference this control in code and while all public methods and properties are available (ie MyControl.TitleString = "Hello";MyControl.DoSomething();) none of the ASP controls are. Rather, they are all null. So MyControl.buttonSave is null, MyControl.LabelTitle is null, etc. Is this by design? Am I missing something? If not, what's the point of being able to create dynamically do this?
I want to create columns in gridview dynamically based on rows in a table and each gridview colum should have a checkbox. When I Click the save button, I want to save the checkbox state. How Can I do this ?
I am dynamically creating initial rows and cells in a asp:table on Page Load, whose cells need to have embedded user controls.
I have an Add Row button, where in, whenever I click I need to add rows to existing table and also persist viewstate of the user controls already added earlier to cells during initialization.
When I click on Add button, the controls disappear. how to recreate tables with their embedded user controls and populate the viewstate.
This is the basic piece of code I have currently and I am stuck -
Using C# and SQL server. I need to dynamically format a web page which is intend for reporting. I have 2 SQL tables. Projects ( Project ID and Project Name) and Subprojects ( SubprojectName, ProectID, EmployeeName, Decription). Subprojects are linked to the projects throughthe ProjectID field
Needed format; Employee Name
All the project for that EmployeeName All the SubProjects for that EmployeeName undre the given project + Description of the subproject Eg: Peter Project A SubProject AA <subProject AA Description > SubProject AB <subProject AB Description > SubProject AC <subProject AC Description > Project B SubProject BA <subProject BA Description > SubProject BB <subProject BB Description ANN Project C SubProject CA <subProject CA Description > SubProject CB <subProject CB Description >
I have to show progress bar in datalist and having following scenario:
I am collecting response for the questions For each answer, total no of responses and their respective Percentage(%) is calculated
Now I have to show this % progress in progress bar
means if a answer have 100% response then progress bar show 100% (100% filled) if it have 50% response then only half of progress bar is filled (50% filled)and so on. response is calculated upto one decimal places(like it can be 33.3% or whatever)and respective % have to be shown in progress bar
So I have to create progress bar dynamically for each response %
How to display % in progress bar, I am using asp.net 2.0 with C#..
I've an item template inside a grid which has a <asp:LinkButton/> inside it. I assign the text for the link button as
<%# Convert.ToString(Eval("Tags"))%>
Tags can have a string with multiple tags in it delimited by space. For eg. "sports", "sports cricket", "sports cricket sachin" are the examples of some possible tags.
I want to create a button for each tag inside the string. How can i create the controls (server control - linkbutton) dynamically during runtime inside the grid item template?
I have written some code to dynamically generate template columns for gridview which works well. However, each cell in the gridview has to be a linkbutton, which when clicked does a db update and redirects to a specific url with some parameters in it.
I have attached a click event handler to the linkbutton in the InstantiateIn method but the event does not seem to fire.
//Dynamically creating the Grid protected void btnAnalyze_Click(object sender, EventArgs e)
I am stuck in chart controls...Here is my prob... There is a ListBox containing some items...when user selects multiple items from the list box I want to generate a dynamic table with the number of columns same as that of the number items selected in the listbox. And for each selected item I want to show a seperate chart in the columns...Currently I want the same chart control for every selected item (i.e. a static hard coded chart that i will replace later by dynamic values)....I am using a method that draws a chart control using a sample dataset... I am calling it each time when a new column is created..Also the DrawChart method executes for the first column only and throws an index out of range exception! after the first execution...my code is not working...here
