After postback (click on a button) in my ASP.NET form, all the DataItem of my form are null. Why? What should I do to retrieve the content of the DataList even after postback?
protected void buttonAddRecord_Click(object sender, EventArgs e)
{
foreach (DataListItem item in listFields.Items)
[code]...
I have a
<%# DataBinder.Eval(Container.DataItem, "starttime") % >
i.e. starttime is field in mysql which i bind to asp:Repeater. and want to print as <span>Start Time:
<%# DataBinder.Eval(Container.DataItem, "starttime") %> </span>
if starttime is not blank ..and if blank, print nothing.. How to do this in asp.net ...
How to deal with Null values in GridView Container.DataItem
[Code]....
In a nested GridView (GridView inside a template column of parent GridView). I am binding child GridView to a DataTable in parent GridView's RowDataBound event. this works as it should. But the problem i am facing is in Child GridView's RowDataBound Event, when i try to access e.Row.DataItem property it returns null. I am expecting it to return DataRowView Type. which i will then use to set values of TextBox's.
[code]....
I have a datalist with price label
<asp:label runat="server" ID="lblPrice" Font-Bold="true" Font-Size="Medium"> <%# DataBinder.Eval(Container.DataItem, "dProduct_price") %></asp:label>
i have used to find the control in my code but when i debug the value is null
Label price = (Label)e.Item.FindControl("lblPrice");
For example in my datalist if Eval("OptionJ").Tostring = Null I would like the function GetVisible to set visibility of the radio button to false like so:
<input name="Q<%#Eval("ID")%>" type="radio" value="J" visible="<%# GetVisible(Eval("OptionJ").ToString()) %>">
<%#Server.HtmlEncode(Eval("OptionJ").ToString())%>
</option><br />
I then have a codebehind function like so:
Protected Function GetVisible(ByVal Evalresult As String) As String
If Evalresult = Nothing Then
Return "False"
Else
Return "True"
End If
End Function
I have also tried checking EvalResult = String.empty
In the outputted html the visible status is being set to false...
<input name="Q3" type="radio" value="J" visible="False">
But it is still displayed on the page!
i have datalist.i can bind datalist but problem is that null value does not bind.but all values are not null.
my scenerio is asign click btn click then view open then insertion and save.if free class btn click then another view open and then insertion...in asign class it can bind but free class not bind.while i m providing day and period also.so why they canot bind?
So I have followed this tutorial to try and me edit a record in a datalist.
[URL]
When I click update after updating anyfield it throws a NullReferenceException was unhandled by the user code. Here is my code.
protected void DataList1_UpdateCommand(object source,
am using a gridview, which is inside datalist, but whenever I try to serach gridview in datalist it reyurns NULL. I using the following code, bolded line is not able to assign gridview:
amespace DataListXML
i am trying to maintain some data into cookies but after postback if i check the value of the cookies in pageload the value is always null
this is how i set and get the cookies
private static string GetCookie(string name)
{
return HttpContext.Current.Response != null ? HttpContext.Current.Response.Cookies[name].Value : string.Empty;
}
private static void SetCookie(string name, string value)
{
HttpContext.Current.Response.Cookies[name].Value = value;
HttpContext.Current.Response.Cookies[name].Expires = DateTime.Now.AddDays(ExpireTimeInDays);
}
I've got a weird problem with a NullReferenceException on a high traffic website my company hosts. The exceptions are logged with full stack-traces but I am unable to reproduce it.The exception occurs a couple of times a day, for different users, and it's a NullReferenceException thrown in the code block below:
protected void Page_Load(object sender, EventArgs e)
{
...
if (!Page.IsPostBack)
{
...
this.ViewState[StaticClass.StaticStringProperty] = StaticClass.StaticIntProperty; // this is the line the exception occurs on
...
}
}
The only place I can figure that a NullReferenceException would be thrown is if ViewState is NULL, but I've never known that and can't find any reason why this would be the case in a Page_Load that isn't a postback.StaticStringProperty and StaticIntProperty are both initialised, static properties of StaticClass.
StaticStringProperty is defined as:
public const string StaticStringProperty = "IdFromClient";
Does anyone know how this could happen, or any other reason why a NullReferenceException would be thrown on the above line?
EDIT.As requested, the full stack-trace for the error is as follows. Line 54 is the line I've highlighted above.
at MyCompany.MyApplication.Appliance.Page_Load(Object sender, EventArgs e) in C:Documents and SettingsshellamaMy DocumentsMyApplicationAppliance.aspx.cs:line 54
at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e)[code]....
I have a asp.net page titled EstMaterials.aspx with a gridview that fills from a SQL table based on a parameter passed to it. The code for calling the form is below.
<asp:UpdatePanel ID="upAddMaterials" runat="server">
<ContentTemplate>
<div id="AddMaterials" style="text-align:center">
<asp:Button ID="btnDecoy" runat="server" Text="Decoy" style="display:none" />
<asp:LinkButton ID="lbAddMaterials" runat="server" Text="Add Materials"></asp:LinkButton>
[code]....
I have an a button field set as a link in a gridview. When the user clicks on the link it should open the "EstMaterials.aspx" page with a gridview listing the materials required for this job. If I do not have a parameter i.e, ScheduleWeek.oJob.JobSeqNbr, the gridview fills fine. However, with the parameter listed the gridview does not fill. It appears the form opens without ever looking at the parameter being passed.The page load event is below.
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not IsPostBack Then
If Not IsNothing(ScheduleWeek.oJob) Then
Dim tbl As New DataTable
[code]....
I have a simple page containing a GridView control that generates thead and tbody tags after rendering. In my jQuery script, I have a line that reads this way:
$('#GridView1
thead').eq(0).html()
When the page loads for the first time, this script returns an objects and works well. But when I click a button and cause a postback, it returns null. By the way, the button changes the number of the rows returned from the data source (based on the value of a textbox) and updates the grid.
Im currently experincing some difficulties with the viewState. The scenario is that i have a datagrid that has a column of buttons that when pressed will store a value in the viewState. I have already done this on one occasion in the same page, but for some reason the second item in the view state is always returning null, even when i hardcode in a number in before the postback. Im at a loss as to why this is happening, anyone expericened this and know what is wrong.
EDIT: Ive found out the cause, Its due to when you click a button in a data grid it does the postback code first, then fires the event handler, so of course the view state would be empty as it is coded to be set in the event handler for the button click. Is there any way to avoid that? So the event code is fired before the postback code?
I'm having a really difficult time getting a DataList to work at all. When nothing is bound to the control (this happens before postback) I get an error.
<asp:DataList ID="ResultBox" runat="server">
<ItemTemplate><%#DataBinder.Eval(Container.DataItem, "Loc")%><br>
</ItemTemplate>
</asp:DataList>
I get the error: DataBinding: 'System.Data.DataRowView' does not contain a property with the name 'Loc'.
I know it doesn't contain a property with the name 'Loc' because I haven't bound anything to the control, which I only do after hitting a Submit button and postback.
How do I get around this so it conditionally evaluates the DataList?
In asp I want to add row to my gridview when I read barcode. But when I want to add second row , gridview.datasource = null. So, my first row is removed from gridview in TxtBxBarcode_TextChanged event.
TxtBxBarcode and gridview are in the different update panels.
How can I prevent this "gridview.datasource is null when Postback" ?
I've been looking around and trying a lot of different tactics to solve this issue but basically the senario is this.I have a gridview with a fileUpload in it.I can upload a file perfectly and it writes to the database.The trouble starts when I update a different cell and don't touch the cell with the fileUpload in it,it'll postback a null value to the database.
How can I keep the fileUpload control from sending a null on postback to the database so it won't clear out my entry if there isn't a new one to replace it?Or alternatively,how to I default the value to the old value on postback if nothing was entered through the FileUPload control?
[Code]...
I am using datalist and used custom paging for that but on page index changed there is full postback..because i am sending the values through querystring just have a look to this link
[URL]
i want to remove this postback...
I have a GridView and a DataList on the same page in a father/son relationship.I am trying to have the selected row on the GridView be in 'focus' on postback so if a person toward the bottom of the list is selected then the scroll position is maintained.I am trying to do the same with a DataList too.Heres my javascript.
[Code]....
and I have this around the GridView :
[Code]....
and this around the DataList:
[Code]....
The funny thing about this code is when I comment out the DataList portion, the GridView scroll postition works, when I comment out the GridView javascript portion the DataList scroll postion works.Is there a special way to make sure both of these can work or is it a javascript issue?
A common problem in repeater controls where you want to display data for update (like a list of user phone numbers that can be updated and submitted back to the database) is where to store the database unique row identifier. So, I created a custom Textbox control that I've added a Data property to. I populate this data property with the unique row id. The problem is that when I post back the list and go through the repeater items the control's data property is null. The custom control looks like this:
[Code]....
The tag in the repeater looks like this:
[Code]....
I have a custom checkbox with the same data property and it works fine. I actually put in the same repeater with the textbox control and the checkbox control have the row id on postback but the textbox did not. Is there some limitation on the textbox control that might be causing this.
I have a UpdatePanel which is having a Datalist inside it , and in datalist i have a country dropdownlist whose autopostback = true , now it is causing postback which i want to trigger , but i am unable to set it as AsyncPostBackTrigger inside update panel because update panel won't find the dropdownlist as it is in datalist.
View 1 RepliesThe following code works well as long as I pass a querystring value to the datalist.
Private Sub BindGrid()
Dim id As Integer = Integer.Parse(Context.Request.QueryString("id"))
Dim strConnString As String = ConfigurationManager.ConnectionStrings("Conn").ConnectionString
Using con As New SqlConnection(strConnString)
Using cmd As New SqlCommand()
cmd.CommandText = "select Id, Name from tblFiles where Id=@Id"
[Code] ......
However, the page errors with the message "Value cannot be null." if I don't pass a value. I know that DataList does not have an EmptyItem Property like a Gridview control. I do not want the page to error if I don't pass a value. Need info to deal with empty values in a datalist.
Most websites have pointed me to this code to use:
<FooterTemplate>
<asp:Label ID="lblEmpty" Text="No Result" runat="server"
Visible='<%#boolean.parse(([b]list[/b].Items.Count=0).ToString())%>'>
</asp:Label>
</FooterTemplate>
The 'list' throws an error. The error is "Too few type arguments to 'System.COllections.Generic.List". I am not sure if the code is written in C# and that is what is causing the error. It seems that it should work but I can not figure out the 'list' error.
I use this bit of code in the code behind a OnRowDataBound comand of a gridview:
Code:
(int)DataBinder.Eval(e.Row.DataItem, "SectorID")I have made some changes to my Class so that SectorID is now a list of ints. How do i return the first item in the list using the above method?
i am new in ListView Control. I have a List view to show shopping products. in each data Item i put a link-button for "Add to cart" button. in my scenario clicking on this button causes ShoppingCart.Instance.AddItem("Product GUID") to call. how can i perform that?
i set CommandName="Select" in Link Button and performed this:
[code]....
I'm using DataTable for DataBinding.
Can I access dataitem (I think its suppose to be DataRow in my case) from aspx?
Something like:
<img alt="" src='<%= DataItem("ColumnName") %>' />
