I am using a list of objects as a datasource and passing the object into a user control. I use the code outlined below
[code]...
When I try to access the object this way, it's null.
Funny thing, I can access the user control and all the control data in the user control, but the object (both in the gridview and passed to the user control) are null.
I have this part in the Gridview.
<asp:TemplateField HeaderText="Student">
<ItemTemplate>
<asp:DropDownList ID="ddl" OnSelectedIndexChanged="ddl_IndexChanged" runat="server">
</asp:DropDownList>
[Code]....
After the change, when it is to bind data, I get this Exception message. Why?Object reference not set to an instance of an object.
When my page is first loaded i receive error message stating to the effect
cant find Email for GetInvoicesByVendor.
this refers to a function in another class file:
Public Shared Function GetInvoicesByVendor(ByVal Email As String, ByVal vendorid As Integer) _
As IEnumerable
yet i only want to execute this function during the button click event and not when page is first loaded with the following parameters:
vendorid.Text = 1
txtcustomerid.Text = test@yahoo.co.uk
My objectdatasource is declared as follows:
<asp:ObjectDataSource ID="ObjectDataSource1" runat="server"
OldValuesParameterFormatString="original_{0}"
SelectMethod="GetInvoicesByVendor" TypeName="InvoiceDB">
<SelectParameters>
<asp:ControlParameter ControlID="txtcustomerid" Name="Email"
PropertyName="Text" Type="String" />
<asp:ControlParameter ControlID="vendorid" Name="vendorid" PropertyName="Text"
Type="Int32" />
</SelectParameters>
</asp:ObjectDataSource>
I have a GridView inside an UpdatePanel in which there is a TemplateField column. I need to save the value of this column every time a user changes it. The problem is that when the TextChanged event causes a postback, the GridView datasource is set to nothing. I've noticed that this happens every time there's a postback. Why?
Here is the code:
[CODE]
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Prova.aspx.vb" Inherits="Prova" %>
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 want to display images, which i stored in the MSSQL 2008 with the type of varbinary, in a gridview.
I am using N-Tier to support my web application, i can get the image's value which is in binary type, but i do not know how to display it via a gridview.
I have an object datasource which is using Business object as a myconnection
The method i have defined under myconnection is
Publicstatic
DataTable getfn(String dtype,
String did,
String dprefix,
String dname)
{
datable table = new datatable(); then declared stored proceedure and defined parameters and assighned values
In the stored proceedure it has a query like select column1,coloumn2,coloumn3 As Call from table where
I need to take data from Call and display it to the gridview through object datasource .
I have tried to query a table with an xml column by using XQuery and I can't get the Select to work.
All my knowledge/understanding of the subject comes from this MSDN article:
[URL]
so I am probably overlooking something minor:
I tried this query Select col1, Phone.Query('element CellPhone {I am not sure about what goes here} I tried {data('Phone/cellPhone} from aTable Where Phone.Exist('/Phone/cellPhone/text()[contains.,"412-8977"]') = 1 This syntax is definitely not fun.
I am trying to get the value of the id field in my gridview but I keep coming up with this error when i do selectedValue or selecteIndex
Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
How do I get that id? What I am trying to do is when the user select that link it will delete that information from the database. Here's my code:
[Code]....
[Code]....
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
[Code]....
In the same Code behind file I have:
// This works
Label lblTopNavBarInfo = (Label)Master.FindControl("lblTopNavBarInfo");
lblTopNavBarInfo.Text = "Currently Serving: + FirstName + " " + LastName ;
// This compiles but throws an error in the browser
LinkButton lnkBtnProductsOwned = (LinkButton)LeftNav_CustServ1.FindControl("ProductsOwned"); // The Control is visible
lnkBtnProductsOwned.Enabled = false; // Error: Object reference not set to an instance of an object.
I have GridView control with a checkbox in one of the columns. When I click a button to submit, I want to see if the checkbox is selected, but when I do, it only gets "Yes" for Label but false fo Checked. I know I am accessing the column because I get the Label. Wha tam I missing?
<asp:TemplateField HeaderText="OverRide">
<ItemTemplate>
<asp:CheckBox ID="OverRide" runat="server" Text="Yes" />
</ItemTemplate>
</asp:TemplateField>
//Code Behind
//Where i = the row
CheckBox cb2 = ( CheckBox )GridView2.Rows[j].Cells[7].FindControl("OverRide");
From what I understand within the Gridview Object you can have many datakeynames.
I have the field like this DataKeyNames = "id1, id2"
However, i don't know how to access the DataKeyNames individualy. For example. How do you access the first ID for the for a given row or the 2nd ID for a given row????
I currentlly am trying to get a bit value from a specific cell, i can get a text value from text cell but i cant seem to fiqure out how to access the bit value. This is on a dgvRowCommand event so im using datakeys to access the row and a column index for the coloumn like so.
lblFolderRead.Text = dgvCollabFolder.Rows[currentIndex].Cells[1].Text;
This works if im trying to get a text value but obviously a bit value isnt text and thus does not return anything, How would i access a bit value in the manner above, or if it is not possible that way what other alterntives are there?
I have a webpage that uses a formview. The formview gets the data from the objectdatasource which connects to a query in a table adapter.
I wanted to add a hyperlink in the page right below the formview that will "hyperlink" to another page passing parameters. Those parameters are values from the formview.
Can I just access the parameters of objectdatasource from outside the formview as follows?(it isn't working)?:
<asp:HyperLink
ID="HyperLink215"
NavigateUrl='<%# Eval("VIN", "Contact.aspx?Subject={0}") %>'
runat="server">Contact Us Regarding This Vehicle</asp:HyperLink>
If not, can I access those parameters in codebehind and do a redirect from there? How do I access the data of objectdatasource from codebehind? If I can do that, I could just put a button. Then in the button's click even, I could do the redirect.
Accessing GridView Element of specific row?
GridView1.DataSource = newDs;
I have taken checkbox inside gridview. And also one linkbutton. When i click on linkbutton to check whether this checkbox is checked or not.
I have some code snippest.
[Code]....
I have a Gridview X in which there are 6 columns(5 template columns that are text boxes and 1 bound field). The user has the option of changing the value in the text boxes annd saving them. There is one more GridView Y that displays DB values(all 6 columns are bound fields). Initially X will show the values that being shown in Y, and when user changes the values in Y,he should be able to save it. If we are trying this using OnTextChanged event of asp:Textbox, there is a postback everytime the user makes a change in any of the textboxes. Instead i want it such a way that all the changed values should get concatenated together and should be sent to the DB.
View 4 RepliesIn a page, there is a lable called lblTotal and a gridview with 3 columns; Name, Percentage and Amount.
Name and Percent are values that come from a database. Next I need the caluclate the Amount field. The Amount field should be set by taking the Percentage column value in each row, against the value in lblTotal and displayed in the Amount column
So for example
If the value in lblTotal is £200 and the dataset in my gridview looks like this...
Name......Percent......Amount
John......20%..........
Dave......60%..........
Mark......20%..........
Then the result would be this
Name......Percent......Amount
John......20%..........£40
Dave......60%..........£120
Mark......20%..........£40
So I guess I would need to do this using OnRowCreated and do a find control maybe?
In my application Iam using GridView, in this there are fields (Quantity, Price, Amount) the user can enter Quantity Field value which is a template field (textbox). Iam calculating Amount(Quantity * Price) using Javascript and assigning to the Amount Column cells as below
Gridviewcell.innerText=Quanity * price.
and when user clicks on the Save button I want to add these details of Gridview to the database.
when I try to access the values of the gridview using below code
For i=0 to GridView.rows.count-1
GridView.Rows(i).Cells(2).toString ( for Example)
Next i
It is not displaying the changed value instead it is displaying the default value before calculating the amount.
Before implementing the Javascript part, I had done this in the code behind and it was working fine... Now I just dont want the page to get load so I used javascript.
able to access the value of Gridview cells which are assigned using Javascript.
I have the following html in my gridview in an item template :
<a
href="<%#Container.DataItem("ReciprocalURL")%>"
target="_blank"
title='<%#Container.DataItem("ReciprocalURL")%>'
id="recip">
So I thought that you could use id="name" and access this just like an ASP control such as <ASP:Checkbox
or <ASP:Label etc. My code continues to caugh and state object not set to an instance of an object when I uncheck my checkbox
Line 741: ElseIf Not Me.CheckBox1.Checked Then
Line 742: Dim row As GridViewRow = gvLink.SelectedRow
Line 743: Dim recip As HtmlAnchor = TryCast(row.FindControl("recip"), HtmlAnchor)
Line 744: Response.Write(recip)
Line 745:
[Code]....
 I am trying to implement the code URL...I have a database table with Integer type.Here is the running code line: Code in GridView:
<asp:TemplateField HeaderText="RegionNavn">
<ItemTemplate>
<%# Eval("RegionNavn")%>
</ItemTemplate>
<EditItemTemplate>
<asp:Label ID="lblRegionNavn" runat="server" Text='<%# Eval("RegionNavn")%>' Visible = "false"></asp:Label>
[code]...
On Edit Click, the DropDownList in the GridView brings the previously selected value.On Update Click, the error is:Â "System.FormatException: Input string was not in a correct format."
dCmd.Parameters.Add("@KystverketRegionID", SqlDbType.Int).Value = int.Parse(ddKystverketRegionID.SelectedValue);
Â
When I use the following code:
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 ?
I've a listview where in am using object datasource to bind the data.I've few questions with the object datasource. Will object datasource load the page twice?Also is there any way to stop listview autobind with object datasource i.e i want the listview binding to be controlled by code behind. Now i see i cant control the listview binding on page load.. object datasource is taking care of that?The problem i'm facing is that am getting my control coming to page load twice.
View 3 RepliesWhen 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"))
[Code] ...
HTML code:
<asp:GridView ID="GridView1" runat="server" CellPadding="4" EmptyDataText="no record found" ForeColor="#333333" GridLines="None" AllowPaging="True" HorizontalAlign="Center" Width="303px" AutoGenerateColumns="False">
<AlternatingRowStyle BackColor="White" ForeColor="#284775" />
<EditRowStyle BackColor="#999999" HorizontalAlign="Center" VerticalAlign="Middle" />
<FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
[Code] ....
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?