why asp.net does not render a dropdownlist with the autopostback property set to true when using the RenderControl method.
eg
Dim sw As New IO.StringWriter
Dim tw As New HtmlTextWriter(sw)
Dim table As New Table
[Code]...
my output renders the dropdown list without the onchange="javascript:setTimeout('__doPostBack(ddl1','')', 0)" that is generated by asp.net when using the dropdownlist normally.
I am trying to find out what html is generated when a control is rendered. For most controls, the following worked fine: Dim tempbuilder As New System.Text.StringBuilder() Dim tempwriter As New
System.Web.UI.HtmlTextWriter(New System.IO.StringWriter(tempbuilder))
Dim generatedhtml as String Me.imgImage.RenderControl(tempwriter) generatedhtml = tempbuilder.ToString()
However, when I tried doing it with an ImageButton, I recieved the following error: Control 'ctl00_cphExampleContent_imgButton' of type 'ImageButton' must be placed inside a form tag with runat=server. What can I do to avoid this?
I've got a server control that renders out a series of dropdownlist and a checkbox that all have autopostback set to true. When the control renders the onchange event binding is not written out!
Controls are defined as protected, named and added to the controls collection in OnInit, and rendered via RenderControl(writer). Page.requiresPostback is also set.
ANy ideas why this might be? I'm scratching my head.
/* chopped version of the code in question */
[Code]....
I am using TreeView Control in Asp.net. I have placed this control inside a panel. The tree control is completely binded (we don't want populate on demand) with an Xmldatasource during a callback and then I call Panel.renderControl to return the response (HTML) to the client side callback handler. Problem: 1. The tree expand/collapse (on click of plus sign) is causing postback whereas when I normally bind a tree with xml during postback and without using renderControl of container control, the expand/collapse (on click of plus sign) is being handled at client side. I want to stop this postback and allow tree node to call javascript to toggle nodes as it does when tree is binded and renderd in case of normal page life cycle.(when render control function is not used)
View 1 RepliesI have a code like this
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
string strConnectionString = ConfigurationManager.ConnectionStrings["SqlServerCstr"].ConnectionString;
SqlConnection myConnection = new SqlConnection(strConnectionString);
myConnection.Open();
string musisim = DropDownList1.SelectedItem.Value;
SqlCommand cmd = new SqlCommand("select B.HESAP_NO FROM YAZ..MARDATA.S_TEKLIF B WHERE B.MUS_K_ISIM = DropDownList1.SelectedItem.Value", myConnection);
Label1.Text = cmd.ExecuteReader().ToString();
myConnection.Close();
i have a customer name as "MUS_K_ISIM" and his number as "HESAP_NO" All i want is, (autopostback is true) automaticly getting label "HESAP_NO" with who has this number "MUS_K_ISIM" in Dropdownlist. How can i do that? Error: Description: An unhandled exception occurred during the execution of the current web request. review the stack trace for more information about the error and where it originated in the code.
Have a dropdown list with autopostback set to 'yes' have another dropdown list box that will be populated based on the selection of the first dropdown. It works fine until I put a submit botton on the form. When I do it appears to not do the auto postback until the submit button is pushed. Can you have a submit button on a form that has a dropdown with autopostback active.
View 2 RepliesWhen I select the item in 1st dropdownlist, values are fetched from database and want to display in second dropdownlist... but the autopostback is not working for the 1st dropdownlist..
View 1 RepliesI want to show a confirm dialog when the user selects an item in a DropDownList. If the user presses "Cancel", I want to stop the postback. Here is the function I add to the onchange event:
function imitateConfirmUnload(event) {
if (window.onbeforeunload = null)
return true;
return confirm("Are you sure you want to navigate away from this page?
You have unsaved changes
Press OK to continue or Cancel to stay on the current page.");
}
And this is the relevant bit of code in my startup script to add the handler to the event:
[code]...
The problem is that the postback occurs even if the user selects "Cancel". If I move the handler on to the click event, it works. But it feels clunky to me.
Edit
Correction: it doesn't work onclick, because the dialog prevents selection, so when the user selects OK, no change has taken place, and no postback when you want it!
Edit 2
The DropDownList is inside an UpdatePanel so that may affect behavior.
I really have no idea on this problem on the cascading dropdownlist. I have a cascading dropdownlist that bind with calling the web services.
I wan to do a autopostback to get the value of the Album GUId so that i can query out all the photo list of that album. it is working well if my page without the AlbumGUId query string.
my problem is:
when i redirect from other page and passing the Album GUId querystring to this page, it will display all my photo for this album guid. but when i change the album to Select which should be able to display all the Photos, it cannot display out. It only will work is when i choose another album and then go back to Select then it only can work..
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Well I have a strange problem.I have a page with 2 DropDownLists on it and a custom web-user-control. The custom web user control has an UpdatePanel within it, and an Ajax Timer control within the UpdatePanel to periodically update a listing of stuff.When I "drop-down" one of the DropDownLists and hover over (not click on) an option while the Timer control within the UpdatePanel asynchronously posts back to the server, the DropDownList "autopostbacks" to the server!
I'm trying to figure out why an asynchronous postback would cause the DropDownList to act as if I selected/clicked on an option so that I can find a way around this issue.Now it's really simple to reproduce this problem. Create a Web User control called "TimerUpdatedListing"...this is the ASPX code markup for the web user control:
<%@ Control Language="vb" AutoEventWireup="false" CodeBehind="TimerUpdatedListing.ascx.vb" Inherits="MyNamespace.TimerUpdatedListing" %>
<div style="width: 150px; height: 150px; overflow: auto; border: solid 1px navy;">
<asp:UpdatePanel ID="anUpdatePanel" runat="server">
[code]...
I have a required field validator to validate a dropdownlist. this dropdownlist is an autopostback one, and it's causevalidation property is set to be false.the issue is, when I select the default item, the validation message shows, but the still do the postback. And after the postback, the message disappers.here is the snippet of codes:
<asp:RequiredFieldValidator ID="ContactMethodRequired" runat="server" ControlToValidate="ContactPreferences"
Display="Dynamic" ErrorMessage="Please choose your contact method"
EnableClientScript="true" InitialValue=""></asp:RequiredFieldValidator> [code].......
i have two dropdownlist in my webform both are filled dynamically in the page_load event
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Am using DropDown list. Whenever Autopostback is true it selecting first value of dropdown list...
View 1 RepliesMy dropdownlist having data from database added with the following item:
DropDownList.Items.Insert(0, new ListItem("Please select", "0"));
The sites I mantain are using way too much ViewState and I'd like to reduce that so the size of the page is reduced. I've done a lot to remedy this but I have an issue relating to DropDown lists that use AutoPostbacks.I have a dropdown list with a lot of list items and a good part of the ViewState usage is to hold the list item data. If I disable ViewState and set the AutoPostBack property to true, the page will post back and in the page load I am trying to repopulate the dropdown list with cached data. However, it seems that the SelectedIndexChanged event doesn't fire when EnableViewState="false".Is it possible to make this work without enabling ViewState for the drodown list?
View 6 RepliesI have a DropDownList in a GridView with AutoPostBack="true" and on SelectedIndexChanged fires an event.
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Everything works fine across browsers as long as the user is scrolling through the DropDownList using a mouse.In IE8, things start to go haywire when the user is navigating the DropDownList using up/down arrows on the keyboard. The SelectedIndexChange event is fired with nearly every up/down key pressed. In Firefox 3 and Chrome 9, the behavior is more like what I would expect, that the event isn't fired until the user stops on DropDownList selection and hits the enter key.
Is there something that I should be doing in IE, short of setting AutoPostBack="false", so that the event is fired every time the up/down arrows are used on the keyboard?
I have a Gridview that provides the user the student name for a particular class, a dropdown list to enter grades. If a grade of 'U' is given, a textbox appears in which the last day of attendance must be listed.
It works... though not as conviently as it could; the faculty would like to be able to tab from one dropdownlist to next in succession.
On each ddlGrades changes I write the value to the database and if a 'U' was chosen, display the textBox... but I can't figure how to set focus on the next ddlGrades control, or even the same ddlGrades control that initiated the postbock.
Below is my simplified .aspx followed by the codebehind
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I am having a problem with dropdownlist auto post back set to true...
In my project I have to hide and display two other dropdown lists depends on selected index change of a main dropdown..
I set the auto postback to true and I am hiding and displaying the dropdowns on user selection...Everthing is working fine..
But I am having a very hard time when user types when the dropdown got focus..this is very annoying situation..if type one word its doing a postback and they are unable to type further...
is there any way to fire this onselectedindex change event on blur or on enter key press...is there a way of doing it with java script or jquery...
I have applied your code to print all pages of grid view, and it is throwing an exception that grid view control must be placed in Form tag with runat=server, my gridview control is already in Form tag with runat=server,
Then I tried to override VerifyRenderingInServerForm even as you explianed, i am using asp.net 2.0, when i write
publicoverridevoid VerifyRenderingInServerForm(Control control) {
/* Verifies that the control is rendered */
}
It gives an error that no suitable method found for override...
I am using an asp.net autopostback enabled dropdown list. Here i want to restrict the autopostback property fot the value "Select" in the ddl. I have used javascript for this purpose. but not working.My code look like this.
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I have a ListView that I need to populate a dropdownlist while rendering. For each rown in my table has a field called sizes which has data that looks like this "blue; red; yellow; green", I need to render a dropdownlist in the ItemTemplate with these values, I tried placing a PlaceHolder but I don't know how to populate it. I have tried to populate it OnItemDataBound and OnUnload but neither seem to work.
View 1 RepliesI have following *.aspx page
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Test.aspx.cs" Inherits="Admin_Test" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
[code]....
When I change the value in dropdownList (in browser), it does PostBack, but it selects the first item of list after PostBack - it doesn't save my value.
GetAllDepartments(isDeleted) is a stored procedure, it returns a List of objects with two properties - FieldKey and Name.
have a ASP.NET page for mobile view.On that page I have this part:
[Code]....
While testing this on normal computer using IE7 IE8 it fires the AutoPostBack Control.BUT TESTING IN IPHONE THIS DOES NOT FIRES....ALSO THE DISPLAY IS WIERD BECAUSE A SEPARATE BOX APPEARS AT THE BOTTOM TO SELECT THE LIST.
IAm using ASP.NET Ajax.
Iam having a Update Panel with DropDownList with AutoPostBack="True"
I dont want to postback it, but it going postback, i dont want AutoPostBack="false"
.
Here my code:
<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server" EnablePartialRendering ="true" >
</asp:ScriptManager>
<br />
<br />
<div>
</div>
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack ="true" OnSelectedIndexChanged ="DropDownList1_SelectedIndexChanged" >
<asp:ListItem Value="0">----Select----</asp:ListItem>
<asp:ListItem Value="101">General Admin</asp:ListItem>
<asp:ListItem Value="102">Admin Assistant</asp:ListItem>
<asp:ListItem Value="103">Software</asp:ListItem>
<asp:ListItem Value="104">Recruiting</asp:ListItem>
</asp:DropDownList>
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode ="Conditional" >
<ContentTemplate >
<asp:DropDownList
ID="DropDownList2" runat="server">
<asp:ListItem Value="0">----Select----</asp:ListItem>
<asp:ListItem></asp:ListItem>
</asp:DropDownList>
</ContentTemplate>
<Triggers >
<asp:AsyncPostBackTrigger ControlID ="DropDownList1" EventName ="SelectedIndexChanged" />
</Triggers>
</asp:UpdatePanel>
</form>
I want to do a Jquery POST and get a chart using renderControl attribute of CHart which will return HTML attributes back to browser. The CHart is created dynamically based on parameters passed from post and from model. I have successfully done this on WEbforms,
However the same with MVC give a empty image. The handler doesn't perform the same in MVC2 3.5. I went near to 50 sites now.
I can't use other solution like base64encoding as IE6, 7 don't support it.
What I'm trying to do? I have few data parameteres to be sent (POST) to server and in response get the Chart image as tag along with other attributes and data appended in HTML form and sent to browser, all this to be done using JQUERY. No postbacks to be used.
I have badly searched on google, bing nothing turns out to be valuable.