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Attaching a click event onto an image within a grid view

I am having trouble attaching a click event onto an image that I have stored within a grid view. Basically it is a delete button that will allow the user to delete a specific row depending on where the button is. I have the code in c# ready for it, however, I cannot seem to attach a click event to it.
This is the markup code of the button
<asp:TemplateField HeaderText="Remove" ItemStyle-HorizontalAlign="Center">
<ItemTemplate>
<asp:ImageButton ID="imgbDeleteP" runat="server" BORDER="0" CausesValidation="false" ImageUrl="~/img/Del.png" Height="25px" ImageAlign="Middle"
onClick ="gv_Quals_RowCommand" CommandArgument="<%#Container.DataItemIndex%>" CommandName="Remove" />
</ItemTemplate>
onClick ="gv_Quals_RowCommand"
Here is the code in c# for the click event
protected void gv_Quals_RowCommand(object sender, GridViewCommandEventArgs e)
{
if ((e.CommandName == "Remove"))
{
int index = Convert.ToInt32(e.CommandArgument);
GridViewRow row = gv_Quals.Rows[index];
DataTable dtCurrentTable = (DataTable)Session["CurrentTable"];
dtCurrentTable.Rows[index].Delete();
if ((dtCurrentTable.Rows.Count < 0))
{
}
else if ((row.Cells[0].Text != "*New*"))
{
int appId = 5000;
//int appId = 1;
string insProg = ("delete from projectunitassignment where UnitId =" + int.Parse(row.Cells[0].Text));
SqlCommand cmd = new SqlCommand(insProg, conn);
cmd.Connection.Close();
cmd.Connection.Open();
cmd.ExecuteNonQuery();
cmd.Connection.Close();
RebindCat(appId);
}
}
}
This is the compilation error that I keep getting
CS0123: No overload for 'gv_Quals_RowCommand' matches delegate 'ImageClickEventHandler'
I cannot set the click event through the properties as it is stored within the grid view so I cannot access it through there. Also the click event does not run as I have tested with debugging

The problem is with GridViewCommandEventArgs should be just EventArgs
public void imgbDeleteP_Click(object sender, EventArgs e)
Edit:
I see that in your code you use the Command Argument, so if you want to use that you should see this post
Basically use onCommand instead of onClick or cast the sender to button to get the command argument, something like:
var argument = ((ImageButton)sender).CommandArgument;

Did you try to associate the click event for that grid during page load ?

I think that is because of GridViewCommandEventArgs which commonly used for RowCommand , change it to EventArgs, so that event should be something like this:
protected void gv_Quals_RowCommand(object sender, EventArgs e)
{
ImageButton btn = (ImageButton)sender;
string cmName= btn.CommandName;
string cmArgument= btn.CommandArgument;
if ((cmName == "Remove"))
{
.....
}
}
or to get row index:
GridViewRow gvRow = (GridViewRow)(sender as Control).Parent.Parent;
int index = gvRow.RowIndex;
The first parent is the GridView Cell and the second parent of the GridView Cell is the GridView Row.

gridview and radio button list on browser back button

On my aspx page there is a RadioButtonList and it contains list items named “additions” and “termination”. Also there two gridview “GV_addition” and “GV_termination”. On selecting the radio button “addition”, then the gridview “GV_addition” will be shown. When item “termination” is selected, then the gridview “GV_termination” will be shown.
On radio button changed event, it is working correctly. But my problem is , when I click browser back button, the radio button selection and corresponding grid view not showing correctly. I got issue, “Gv_termination” is showing when radio button “addition” is selected. This issue is showing only when I click browser back button.
Please find my below code
<asp:RadioButtonList ID="RadioButtonList1" runat="server"
onselectedindexchanged="RadioButtonList1_SelectedIndexChanged" AutoPostBack="true">
<asp:ListItem Text="addition" Value="addition"> </asp:ListItem>
<asp:ListItem Text="termination" Value="termination"></asp:ListItem>
protected void RadioButtonList1_SelectedIndexChanged(object sender, EventArgs e)
{
if (RadioButtonList1.SelectedIndex == 0)
{
GV_addition.Visible = true;
GV_termination.Visible = false;
}
else
{
GV_termination.Visible = true;
GV_addition.Visible = false;
}
}
I could not understand why the why the radio button selection and corresponding gridview visiblity is not working on the browsers back button event. Can any one help me to solve this issue?

Please try below steps. For me the same scenario worked.
I could see the values are updating correctly, but the updated radio checked states are not updating in to the UI. So I have set it using javacript on the Onload event of a body.
Add the Onload event on the body.
<body onload="setRadioButonStatus()">
and add the following Javascript.
function setRadioButonStatus() {
var rbtn1 = document.getElementById('RadioButton1');
var rbtn2 = document.getElementById('RadioButton2');
if (rbtn1.hasAttribute("checked"))
rbtn1.checked = true;
if (rbtn2.hasAttribute("checked"))
rbtn2.checked = true;
}

Seems like you aren't creating a "default" scenario. You can do this, and tie the logic together more closely by doing something like this on every Page_Load and leaving it out of your event.
protected void Page_Load(object sender, EventArgs e)
{
GV_addition.Visible = RadioButtonList1.SelectedIndex == 0;
GV_termination.Visible = RadioButtonList1.SelectedIndex == 1;
}
protected void RadioButtonList1_SelectedIndexChanged(object sender, EventArgs e)
{
}

ASP.NET Session State & Postback problems

I have a problem that I believe is a session state issue, but I'm at a loss to figure out what's wrong. I have a sample project to illustrate the problem. (Code below) I have 2 buttons. Each populates a List with some unique data and then uses that data to add a row to a table. The row contains text boxes so that the user can edit the data. (For my sample, there's no update button to persist the data.) To reproduce the problem in VS2010, create a new "ASP.NET Web Application" project and copy/paste the aspx code and the c# code-behind into Default.aspx, then run the application.
Press the DataSet 1 button and the grid should populate with 1 row.
Edit the data in one of the text boxes and tab off of the text box. (The newly entered text should remian, and the font should be blue. This is what I want to happen.)
Now click either of the DataSet buttons to reset the List and refresh the table.
Edit the data in one of the text boxes and tab off the text box. (Immediately, the text in the box refreshes back to its original value. This only happens once, though. If you edit either text box now, it will work normally.)
This is repeatable... the first edit after pressing the DataSet buttons a 2nd, 3rd, etc. time gets reset back to the original value. And I can't figure out why.
<%# Page Title="Home Page" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true"
CodeBehind="Default.aspx.cs" Inherits="DebugPostbackIssue._Default" %>
<asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeadContent">
</asp:Content>
<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">
<h2>
Welcome to ASP.NET!
</h2>
<p>
Populate the table with DataSet #1:<asp:Button runat="server" ID="btnDS1" Text="Dataset 1" OnClick="btnDS1_Click" />
</p>
<p>
Populate the table with DataSet #2:<asp:Button runat="server" ID="btnDS2" Text="Dataset 2" OnClick="btnDS2_Click" />
</p>
<p>
<asp:Table runat="server" ID="tblData">
<asp:TableHeaderRow runat="server" ID="thrData">
<asp:TableHeaderCell Scope="Column" Text="Column 1"></asp:TableHeaderCell>
<asp:TableHeaderCell Scope="Column" Text="Column 2"></asp:TableHeaderCell>
</asp:TableHeaderRow>
</asp:Table>
</p>
</asp:Content>
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace DebugPostbackIssue
{
public partial class _Default : System.Web.UI.Page
{
private List<string> _MyData = new List<string>();
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Page_Init(object sender, EventArgs e)
{
LoadSessionData();
GenerateGrid(false);
}
protected void btnDS1_Click(object sender, EventArgs e)
{
_MyData = new List<string>();
_MyData.Add("111");
_MyData.Add("aaa");
SaveSessionData();
GenerateGrid(true);
}
protected void btnDS2_Click(object sender, EventArgs e)
{
_MyData = new List<string>();
_MyData.Add("222");
_MyData.Add("bbb");
SaveSessionData();
GenerateGrid(true);
}
private void SaveSessionData()
{
Session["MyData"] = _MyData;
}
private void LoadSessionData()
{
if (Session["MyData"] != null)
_MyData = (List<string>)Session["MyData"];
else
_MyData = new List<string>();
}
private void GenerateGrid(bool ClearData)
{
if (ClearData)
while (tblData.Rows.Count > 1)
tblData.Rows.Remove(tblData.Rows[tblData.Rows.Count - 1]);
TableRow tr = new TableRow();
foreach (string s in _MyData)
{
TableCell tc = new TableCell();
TextBox txtBox = new TextBox();
txtBox.Text = s;
txtBox.Attributes.Add("OriginalValue", s);
txtBox.TextChanged += new EventHandler(txtBox_TextChanged);
txtBox.AutoPostBack = true;
tc.Controls.Add(txtBox);
tr.Cells.Add(tc);
}
if (tr.Cells.Count > 0)
tblData.Rows.Add(tr);
}
void txtBox_TextChanged(object sender, EventArgs e)
{
TextBox Sender = (TextBox)sender;
if (Sender.Text == Sender.Attributes["OriginalValue"])
Sender.ForeColor = System.Drawing.Color.Black;
else
Sender.ForeColor = System.Drawing.Color.Blue;
}
}
}

Hi I took some time off of my work to compile your code, and I figured it out, just change your textbox change to the following :
void txtBox_TextChanged(object sender, EventArgs e)
{
TextBox Sender = (TextBox)sender;
if (Sender.Text == Sender.Attributes["OriginalValue"])
Sender.ForeColor = System.Drawing.Color.Black;
else
{
Sender.ForeColor = System.Drawing.Color.Blue;
if (Session["MyData"] != null)
{
List<string> _ss = (List<string>)Session["MyData"];
//_ss.Find(a => a == Sender.Attributes["OriginalValue"]);
_ss.Remove(Sender.Attributes["OriginalValue"]);
_ss.Add(Sender.Text);
}
}
}
ur welcome!

Try creating a datatable. I would, on "event" copy your asp table content to a datatable, then when you get the servers response add that to the datatable. Then copy the datatable back to your asp table, and repeat... Datatables can be used like variables.
Or try using a cookie.

Try changing...
protected void Page_Init(object sender, EventArgs e)
{
LoadSessionData();
GenerateGrid(false);
}
To...
protected override void OnLoadComplete(EventArgs e)
{
LoadSessionData();
GenerateGrid(false);
}
Based on your description I believe that your value is getting reset because of how the page life cycle works in ASP.NET & that is the page_init is getting called before your event due to ASP.NET quirkiness. Above code is how I work around it, I'm sure there's other ways too.

Okay, I have it working, now. Wizpert's answer pointed me in the right direction... Upon discovering that the TextChanged event did not fire during the times when the value was erroneously being reset to the original value, it occurred to me that during the Click events I was calling GenerateGrid(true). This forced the removal of the existing rows and the addition of new rows. (Removing & adding the dynamic controls at that point in the life cycle must be interfering with the TextChange event handler.) Since the Click event fires after Page Init and after Page Load, the state values were already written to the text boxes and I was overwriting them. But the 2nd text box edit did not force GenerateGrid(true) to be called so the state values were not overwritten any more.
If this sounds confusing, I apologize. I'm still wrapping my head around this. But suffice to say that I had to change my GenerateGrid method to reuse any existing rows and not delete them. (If they don't exist, like when GenerateGrid is called from Page Init, then they are added.) So this was a page lifecycle issue after all.
Thank you.

Object reference not set to an instance of an object when tring to set the selection of a combo box

I have a text box and a RadComboBox like this :
<asp:TextBox ID="txt_inner_emp_num" runat="server" Width="60px"
ontextchanged="txt_inner_emp_num_TextChanged" AutoPostBack="true"></asp:TextBox>
<telerik:RadComboBox ID="rad_ddl_inner_emp_name" runat="server" CausesValidation="False"
CollapseDelay="0" Culture="ar-EG" ExpandDelay="0" Filter="Contains" ItemsPerRequest="100"
MarkFirstMatch="true" Width="380px" EnableAutomaticLoadOnDemand="True" EmptyMessage="-emp name-" ShowMoreResultsBox="True" AutoPostBack="True">
</telerik:RadComboBox>
According to the Telerik Documentation
Set a data source to the RadComboBox. Use either DataSourceID or the
DataSource property to do this and set the DataTextField and
DataValueField properties to the respective fields in the data source.
(Note that when using DataSource you must set the property on each
postback, most conveniently in Page_Init.) Set
EnableAutomaticLoadOnDemand to true.
protected void BindEmployees()
{
rad_ddl_inner_emp_name.Items.Clear();
rad_ddl_inner_emp_name.DataSource = Utilities.GetAllEmployees();
rad_ddl_inner_emp_name.DataTextField = "name";
rad_ddl_inner_emp_name.DataValueField = "emp_num";
rad_ddl_inner_emp_name.DataBind();
}
protected void Page_Init(object sender, EventArgs e)
{
BindEmployees();
}
protected void txt_inner_emp_num_TextChanged(object sender, EventArgs e)
{
rad_ddl_inner_emp_name.ClearSelection();
rad_ddl_inner_emp_name.Items.FindItemByValue(txt_inner_emp_num.Text.TrimEnd()).Selected = true;//Get exception here Object reference not set to an instance of an object.
}
I find rad_ddl_inner_emp_name.Items.Count = 0 !! before set the selection ! How to fix this problem ?

As I'm sure you aware of by now, the radcombox typeahead functionality searches text via client side interaction and not by value, which is why you can't find the values.
What I would suggest is having a secondary object to search by emp_num (assuming that's the value that will always be entered into the textbox).
For example, create a global variable:
private Dictionary<string, string> Emp_Dict = new Dictionary<string, string>();
Then populate this dictionary when you do your binding. The following code assumes an ienumerable type being returned. If not you may have to populate the dictionary differently. Also, for this to work, you have to include (System.Linq).
var dataSource = Utilities.GetAllEmployees();
Emp_Dict = dataSource.ToDictionary(ex => ex.emp_num, ex => ex.name);
rad_ddl_inner_emp_name.Items.Clear();
rad_ddl_inner_emp_name.DataSource = dataSource;
rad_ddl_inner_emp_name.DataTextField = "name";
rad_ddl_inner_emp_name.DataValueField = "emp_num";
rad_ddl_inner_emp_name.DataBind();
So now we need to use the dictionary on the text changed event.
protected void txt_inner_emp_num_TextChanged(object sender, EventArgs e)
{
rad_ddl_inner_emp_name.ClearSelection();
if (Emp_Dict.ContainsKey(txt_inner_emp_num.Text.TrimEnd()))
{
rad_ddl_inner_emp_name.SelectedValue = txt_inner_emp_num.Text.TrimEnd();
rad_ddl_inner_emp_name.Text = Emp_Dict[txt_inner_emp_num.Text.TrimEnd()];
}
}
Now when the text changes in the text box, the radcombobox will update when a valid emp_num is entered into the textbox.

The Problem is that the Items only get loaded when you request them!
Set
EnableAutomaticLoadOnDemand="False"
and it will work!
UPDATE:
if you want to use LoadOnDemand set these two Properties and delete the EnableAutomicLoadOnDemand!
EnableLoadOnDemand="True"
EnableItemCaching="True"
UPDATE 2:
Enable ItemCaching isn´t necessary, but it doesn´t hurt!

You do not need to bind data to RadComboBox on every postback unless you disable the view state.
Filter, MarkFirstMatch and EnableAutomaticLoadOnDemand are not useful in your case as you are loading all employees by yourself.
LoadOnDemand basically is when user starts typing inside ComboBox, ComboBox fires ItemsRequested event and retrieves data via ajax.
<asp:TextBox ID="txt_inner_emp_num" runat="server" Width="60px"
ontextchanged="txt_inner_emp_num_TextChanged" AutoPostBack="true" />
<telerik:RadComboBox ID="rad_ddl_inner_emp_name" runat="server"
CausesValidation="False" Culture="ar-EG">
</telerik:RadComboBox>
protected void Page_Init(object sender, EventArgs e)
{
if (!IsPostBack)
{
rad_ddl_inner_emp_name.DataSource = Utilities.GetAllEmployees();
rad_ddl_inner_emp_name.DataTextField = "name";
rad_ddl_inner_emp_name.DataValueField = "emp_num";
rad_ddl_inner_emp_name.DataBind();
}
}
protected void txt_inner_emp_num_TextChanged(object sender, EventArgs e)
{
string value = txt_inner_emp_num.Text;
if(!string.IsNullOrWhiteSpace(value))
{
value = value.Trim();
if (rad_ddl_inner_emp_name.Items
.FindItemByValue(txt_inner_emp_num.Text.Trim()) != null)
rad_ddl_inner_emp_name.SelectedValue = value;
}
}

Since you don't have any item in rad_ddl_inner_emp_name.Items you can set txt_inner_emp_num.Text as selected in ddl.
First check if rad_ddl_inner_emp_name.Items count > 0 then set desired text selected. Or you can check if rad_ddl_inner_emp_name.Items.FindItemByValue(txt_inner_emp_num.Text.TrimEnd()) is not null.

asp.net c# is checkbox checked?

How do I determine if the checkbox is checked or not checked?
Very perplexed why this is not working - it is so simple!
On my web form:
<asp:CheckBox ID="DraftCheckBox" runat="server" Text="Save as Draft?" />
<asp:Button ID="PublishButton" runat="server" Text="Save" CssClass="publish" />
Code behind which runs in the click event for my save button:
void PublishButton_Click(object sender, EventArgs e)
{
if (DraftCheckBox.Checked)
{
newsItem.IsDraft = 1;
}
}
When debugging it never steps into the If statement when I have the checkbox checked in the browser. Ideas?!
I think there maybe some other code affecting this as follows...
In Page_load I have the following:
PublishButton.Click += new EventHandler(PublishButton_Click);
if (newsItem.IsDraft == 1)
{
DraftCheckBox.Checked = true;
}
else
{
DraftCheckBox.Checked = false;
}
newsItem is my data object and I need to set the checkbox checked status accordingly.
When the save button is hit I need to update the IsDraft property based on the checked status of the checkbox:
void PublishButton_Click(object sender, EventArgs e)
{
if (IsValid)
{
newsItem.Title = TitleTextBox.Text.Trim();
newsItem.Content = ContentTextBox.Text.Trim();
if (DraftCheckBox.Checked)
{
newsItem.IsDraft = 1;
}
else
{
newsItem.IsDraft = 0;
}
dataContext.SubmitChanges();
}
}
So, isDraft = 1 should equal checkbox checked, otherwise checkbox should be un-checked. Currently, it is not showing this.

Specify event for Button Click
<asp:Button ID="PublishButton" runat="server" Text="Save" onclick="PublishButton_Click" />

What i can see you have not got a OnClick on your button. So like this:
<asp:CheckBox ID="DraftCheckBox" runat="server" Text="Save as Draft?" />
<asp:Button ID="PublishButton" runat="server" OnClick="PublishButton_Click"
Text="Save" CssClass="publish" />
And then the function should work like it is:
protected void PublishButton_Click(object sender, EventArgs e)
{
if (DraftCheckBox.Checked)
{
newsItem.IsDraft = 1;
}
}

Please replace code as following code..
void PublishButton_Click(object sender, EventArgs e)
{
if (DraftCheckBox.Checked==True)
{
newsItem.IsDraft = 1;
}
}

Try adding onclick="PublishButton_Click" in the button field on the form. And I don't know if it makes a difference, but generated event handlers are protected void.

For me the best solution in the end has been to create 2 separate pages: 1 for editing a news articles & 1 for a new news article. So Ill never then be in the position of a new news data object being created when the page reloads.
Both page return to the article index list page when the save button is pressed and that seems to work with being able to save the state of the draft checkbox and then show the state on the edit page.

The checkbox.checked isn't used in the context you want it to (this is a boolean that if true, will make the checkbox look checked).
What you could do is to use instead a checkboxlist. Then you could do the following:
foreach(Listitem li in CheckBoxList1.Items)
{
if (li.Selected)
{
NewsItem.Isdraft = 1;
}
}