Dears,
Updatepanel is in Aspx page.
I have a fileupload in .ascx control. Ascx user control is added when its called and every thing else (rest of page controls i.e. listview) works fine on ascx control.
Only fileupload is set to null when Add Button click is fired. I have tried accepted code (another thread in stackoverflow Persist FileUpload Control Value) in Page_Load and even Page_Init but still it becomes null.
Kindly suggest.
Related
Please I need someone to help me with this issue:
When I select an item from an .ascx usercontrol 'DropDownList Box' added to a master page with PlaceHolder1.Controls.Add(LoadControl("//UserControls/mycontrol.ascx"));
The .ascx user control disappears after the item has been selected
You don't show your code, so it's hard to provide an exact answer. but probably you add your user control dynamically only one time and it disappears after each postback.
You need to load Usercontrol after each postback so you need to load Usercontrol in something like Page_load method if you don't.
Gridview controls first event that gets fired
I have a Gridview control on an .aspx page. what is the first gridview control event, that gets triggered/fired.
Init() Occurs when the server control is initialized, which is the first step in its life cycle which is inherited from Control.
I have a ListView control and in the LayoutTemplate I have Previous and Next paging buttons. On clicking the buttons, a PageButton_Click event handler in the code behind file is called to do the paging. It works fine, but if I switch off the ViewState of the ListView, clicking the buttons would not be able to call the event handler in the code behind. What is happening here?
all the server controls events are stored in viewstate. if you want to off the viewstate then not any server control work. if you want to off the viewstate then implemented the logic using javascript or jquery.
We have created a UserControl. Inside user control we are creating an update panel. Inside the panel we are creating various controls such as TextBox, Button, DropDownList and ListBox and event associated with them buttonclick(),DropDown_selectedIndexChanged(),TextBox_TextChenged() etc. All the controls(including update panel) are created programatically using c#.
To ajaxify the events we have used ScriptManager.
ScriptManager is added on OnInit function programatically like as shown:
ScriptManager scriptManager = ScriptManager.GetCurrent(this.Page);
if (scriptManager == null)
{
scriptManager = new ScriptManager();
//scriptManager.EnablePartialRendering = true;
this.Controls.AddAt(0,scriptManager);
}
Every time after page load only one event get fired partial postback(which is desired) but after that no event gets fired .
All valid changes have already been done in web.config file for AJAX .
Please suggest the possible cause and solution of the problem.
On a partial postback, the ScriptManager will not be added because you are trying to add it outside the UpdatePanel (where it has to be). This works on the first page load because it's not a partial postback. But after the partial postback, the dynamically added ScriptManager won't be available to the page, and because you are trying to add it outside the UpdatePanel -- AddAt(0,...) - after a partial postback, it won't actually be added. On a partial postback you can only affect things inside the UpdatePanel that initiated the postback.
Bottom line is, you really can't add a ScriptManager dynamically, since it will never be there after a partial postback. Just like you can't dynamically add any other control outside of an UpdatePanel after an event sourced inside it.
I have a FileUpload control in a Wizard control. When I click the finish button, I set a breakpoint and I can see the filepath selected in the FileUpload control as expected.
However, when I Ajaxify this same Wizard, the value in the FileUpload control is always null at this breakpoint, as if a file hasn't been selected.
I know there's a limit where a FileUpload control can't keep its value after postback, but I have the breakpoint selected on the postback and would still expect to see the value.
Please check this thread: File uploading in AJAX updatepanel without full postback
You need a full postback to use the FileUpload control, try adding the FileUpload control to the PostBackTrigger section in the UpdatePanel.
See: Problem using the ASP.NET FileUpload control in an UpdatePanel?