Forms Data Controls :: ListView Delete And Object Reference Not Set
Feb 18, 2011
I keep getting Object Reference not set to an instance of an object errors when I try to use the ListView delete function. It is a fairly freshly created listview and is very close to the original template so not sure what is going wrong. Some possibly relevant code:
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I also put in a breakpoint in the deleting event (only reason I added the deleting event) to look at the status of everything. When I do: Contact delContact = (Contact)e.Entity; and look at the values, the values for almost everything are set to null. It does have the correct value for the ID of the contact object that needs to be deleted. When I continue to step, it jumps to my designer.cs file and appears to break here:
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likely because _Case_ID is null. The exact exception I'm encountering is: System.NullReferenceException: Object reference not set to an instance of an object. While I could probably re populate the object with correct values, that doesn't seem likely to address the real cause of the problem.
I created a ListView and attempted to delete a record using the delete button and native procedures. It failed and threw an error.Pass in a valid dictionary for delete or change your mode to OverwriteChangesIn researching this issue, it appeared there is a problem with the list view when deleteing and ConflictDetection is set to
can you please help me to brainstorm the possible causes of this error. I've got a paged repeater with localisation bound programitcally to an sqldatasource using a stored proc. I can post code if needs be but it's rather long. I'm looking for typical causes of this error + will make note for future reference!
erver Error in '/WebSite4' Application.
Object reference not set to an instance of an object. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
Source Error:
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Line 233:Line 234: Repeater1.DataSource = PagedResultsLine 235: Repeater1.DataBind()Line 236: doPaging()Line 237: End Sub
My problem is I get an "Object reference not set to an instance of an object." error at runtime on the line "ddl2.SelectedValue = cat1". Ironically I got this from an example on the internet and the only difference is my Cat1 varible which has the correct value at runtime.
I would like to enable/disable the field BagNo in my gridview, depending on the value of another field in the gridview called ScriptNo, when I click the edit button I get this message "Object reference not set to an instance of an object".
here is the code
Protected Sub GridView1_RowEditing(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewEditEventArgs) Handles GridView1.RowEditing Dim row As GridViewRow = GridView1.Rows(e.NewEditIndex) If DirectCast(row.FindControl("ScriptType"), TextBox).Text = "TTA" Then
Protected Sub Repeater1_ItemDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.RepeaterItemEventArgs) Handles Repeater1.ItemDataBound ' display placeholder image if no imageId Dim ltrImage1 As Literal = CType(e.Item.FindControl("Image1"), Literal) Dim ltrImage2 As Literal = CType(e.Item.FindControl("Image2"), Literal) Dim drv As DataRowView = CType(e.Item.DataItem, DataRowView) If String.IsNullOrEmpty(drv("ImageId").ToString) Then ltrImage1.Text = "<img src=""images/properties/x_thumb.gif"" alt="""" />" ltrImage2.Visible = False End If End Sub
I need you assistance, Dynamic Delete LinkButton with CommandName=Delete gives me an error: Delete can only be called on a valid data item. nfact I am designing a Complex Grid using .Net 3.5 ListView Control with Scrollbar and Fixed Toolbar: This grid consist of 3 Tables:
1- footer 2- Toolbar Control 3- Scrolling Data Grid with Header
ListView give us only one ItemPlaceHolder to Bind Data as per LayoutTemplate, so I cannot able to manupulate my Toolbar Controls with ItemTemplate :(, therefore I decide to use ItemDataBound to add ImageButtons Dynamically using Init Page Event and I am able to get the result as you saw above:
ImageButton with funnel icon is with CommandName="Filter" ImageButton with magnifier icon is with CommandName="View" ImageButton with stop icon is with CommandName="Delete"
Now I can able to handle Filter and View with OnItemCommand Event but when I click Delete button I am getting an error as shown below: The grid used CSS I am sending you the HTML and code behind to resolved this problem: HTML CODE:
I have created an ASP page to display records for auditor review and response. The page consists of two repeaters that display 5 rows from a database at a time. for each row displayed, a RadioButtonList, containing two buttons is attached. If the second button is selected, an input text box is displayed to allow auditor comments.
My situation is that I cannot find a way to identify which row is being selected? When I select the Button that should enable the text box, I'm receiving the following error:
"Object reference not set to an instance of an object"
I'm just starting out in ASP coding and would like to know what I'm not doing right?
I am using VS 2008 SP1. My also have included CSS Friendly adapter [URL] in my project ( I mentioned this because my GridView Empty data template is not showing when using GridView's CCS Friendly adapter). I have a GridView and a DetailsView. When a record in GridView is selected its details information is shown in the Details View. Type of Data source I am using is ObjectDataSource. My Insert and Update methods works perfectly. It is only the Delete method that is passing null values to the underlying object delete method. My source codes for both the UI, BLL, DAL is shown below
in my default.aspx page i have a dropdown List and a textbox with a submit button below that there are 2 listbox... and the dropdown list holds the names of the listbox
my logic here is to select an item from the dropdown list and put some text in the text box and submit the form which will add an item to the listbox selected.. but when i do this i get an error saying Object reference not set to an instance of an object. i tried to figure out the problem and found that when i remove the reference to the Site Master Page it works fine and when i undo and apply my reference back to the Site Master Page i get the same error.
On Edit Click, the DropDownList in the GridView brings the previously selected value.On Update Click, the error is: "System.FormatException: Input string was not in a correct format."
ddlRegionNavn.DataTextField = "RegionNavn"; ddlRegionNavn.DataValueField = "RegionID"; // from RegionNavn to RegionID
On Edit Click, the DropDownList values in the GridView is not firing and the following error shows.Object reference not set to an instance of an object. How to implement the code when having a value of type Int ?
When I am executing the below code on Visual Studio 2008, then it is executing properly with out any error. But when i am executing it on Visual Studio 2012, then it showing me following error (System.NullReferenceException: Object reference not set to an instance of an object) at line 64
Why is it so?
.vb Code is below :
Imports System.Data.SqlClient Imports System.Data Partial Class grid Inherits System.Web.UI.Page Function constr() As String Dim i As New IO.StreamReader(Server.MapPath("constr.config"))
I have a dropdownlist attached to a cell when edit is selected. I am using the following code to populate the drop down list with the value that is on the row.
dlBU.Items.FindByValue((e.Row.FindControl("lblBU") as Label).Text).Selected = true;
This works famously when I have a value in the cell. It fails when the cell has not yet been populated. Is there an if then clause that if the value of e.Row.findcontrol("lblBU") is null no default value?
First time using a ListView control, I have it inside an UpdatePanel:
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When the UpdatePanel Loads, it feeds the data to the ListView. Whenever the user clicks on a row in the ListView, a new window displaying a "note" pops up, the ItemDataBound event ties it all together. What I'm trying to do is add a button to each row so that the user can delete the row. This would call a Sql statement and then the row should disappear. I followed a couple of articles I found on ListView on how to do this, so I added a button called imgBtnDeleteNote (see markup above) and set the CommandName = "Delete", hoping that it would trigger the ItemCommand and ItemDeleting event (I have some bogus code in them, first I wanted to see if they would trigger).
The problem is that they don't seem to get triggered when I click on the delete button. All the rows in the listview disappear, and when I manually refresh the page they come back. My guess is that the events are not firing because I'm not using a DataSource object in the aspx code, but I'm not sure.
