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Datagrid ItemCommand event not firing

I am still a novice with asp.net, so I'm sure there are better ways to do some of this...
I want to allow a user to enter a date, and then execute an SQL query against a database to return all records matching that date. I want to display those records, and allow the user to select one for additional processing. It seemed like the DataGrid with a column of Pushbuttons was a good choice. In fact, I've done this before, but it those cases there was no user interaction involved. The page just ran a fixed SQL query. With what I'm doing now, the data is displayed as I want, but the Pushbuttons aren't working...the ItemCommand event doesn't fire.
I've read a lot of threads about the ItemCommand event not firing, but I still can't get this to work. My understanding is that I need to bind the DataGrid while not in a Postback, and I think my code does that. When I debug the Page_Load event, I can see that the code inside if (!IsPostBack){} is running, and the session variables have the expected data.
On the page that hosts the DataGrid, I have a 'Find' button that executes a SQL query against a database. The query uses a date entered into the textbox that is on that page. In the 'Find' button click event, I store the results of the query (a DataTable) in a session variable, then do a Redirect to re-load the page.
Once the page reloads, the session variables contain my expected data and the data is displayed in the DataGrid, along with the Pushbuttons. When I click any of the buttons in the DataGrid, the contents of the DataGrid disappear and the ItemCommand event does not fire.
Here's the definition of the DataGrid (updated to include the button):
<asp:Panel runat="server" ID="pnlSelect" HorizontalAlign="Left" Visible="true" style="margin-top:10px" >
Please select a participant.
<asp:DataGrid runat="server" ID="grdItems" AutoGenerateColumns="true" BorderColor="black" BorderWidth="1" CellPadding="3" style="margin-left:2px; margin-top:6px" OnItemCommand="grdSelect_ItemCommand" >
<Columns>
<asp:ButtonColumn HeaderStyle-HorizontalAlign="Center" ButtonType="PushButton" Text="Select" HeaderText="Select" CommandName="Select" >
<ItemStyle Width="60px" HorizontalAlign="Center"/>
</asp:ButtonColumn>
</Columns>
</asp:DataGrid>
</asp:Panel>
Here's the Page Load code (unneeded code-behind stuff is commented out):
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
if (Session["y"] != null)
{
txtFind.Text = Session["x"].ToString();
DataTable table = Session["y"] as DataTable;
Session.Remove("x");
Session.Remove("y");
if (table != null)
{
/*
ButtonColumn buttonColumn = new ButtonColumn
{
HeaderText = "Select",
Text = "Select",
CommandName = "Select",
ButtonType = ButtonColumnType.PushButton,
};
grdItems.Columns.Add(buttonColumn);
foreach (DataColumn c in table.Columns)
{
BoundColumn column = new BoundColumn
{
HeaderText = c.Caption,
DataField = c.Caption,
ReadOnly = true
};
grdItems.Columns.Add(column);
}
*/
grdItems.DataSource = table;
grdItems.DataBind();
}
}
}
}
Here's the relevant 'Find' button event code. I can't post the details of the sql query text, but that part does work and the DataTable does contain the expected data:
DataTable table = DatabaseHelper.FindBySQL(sqlText);
if (table != null && table.Rows.Count > 0)
{
Session["x"] = searchtext;
Session["y"] = table;
Response.Redirect(Request.RawUrl, true);
}
And this the ItemCommand event. I place a breakpoint on the first line, and the debugger never hits it.
protected void grdItems_ItemCommand(object source, DataGridCommandEventArgs e)
{
string item = "";
switch (e.CommandName.ToLower())
{
case "select":
item = e.Item.Cells[1].Text.Trim();
//todo: handle the selected data
break;
}
}
Thanks for any thoughts.
Don

asp.net: How to update data in GridView through Checkbox in particular row

I am developing a Web Form, where I show Gridview with data. One of the column consists of CheckBox. How can I update data in particular row.
so my question is:
How to unidentified particular row and send an sql request with UPDATE when user Check or Uncheck the CheckBox?
Update:
Here is my code that i have. It doesn't update value of CheckBox.
namespace:
public partial class Call_Bills : System.Web.UI.Page
{
SqlConnection con = new SqlConnection();
string check;
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button_Submit(object sender, EventArgs e)
{
foreach (GridViewRow row in GridView2.Rows)
{
con.ConnectionString = ConfigurationManager.ConnectionStrings["TestDeductionsConnectionString2"].ToString();
con.Open();
bool private1 = (row.FindControl("CheckBox1") as CheckBox).Checked;
if (private1 == true)
{
check = "1";
}
else
{
check = "0";
}
SqlCommand cmd = new SqlCommand("insert into DetailCosts(private) values(#private)", con);
cmd.Parameters.AddWithValue("#private", check);
cmd.ExecuteNonQuery();
}}
name of GridView is: GridView2;
name of Checkbox in the Table: private;
id of CheckBox in Gridview is:
<asp:TemplateField HeaderText="Private" SortExpression="private">
<ItemTemplate>
<asp:CheckBox ID="CheckBox1" runat="server" Checked='<%# Eval("private") %>' />
</ItemTemplate>
<HeaderStyle HorizontalAlign="Center" />
</asp:TemplateField>

you can manually define a method to handle a postback generated by a control inside a gridview column. To do that you just need to add the tags AutoPostBack=True and OnCheckedChanged=YourMethodName to the control.
On the code-behind, define this method as public void, and define the parameters that usually would be there (sender as object and e as EventArgs), like:
public void YourMethodName(object sender, EventArgs e)
On the method, you may need to get the GridViewRow which contains the control that has generated the event. To do that, just parse the sender parameter (which will be the checkbox) and get 2 parent levels (GridViewCell and GridViewRow), it would be something like:
GridViewRow row = ((CheckBox)sender).parent.parent;
Since you have the row, you may get any control inside it with the FindControl method. If you need an id to identify the entitiy being updated, you may store it in a hidden field inside the row.
Hope it helps!

Bind a list of users controls to gridview

I desperately seeks in vain. I want to bind a List(T) of Users Controls (.ascx) to a gridview. I initialize my controls in code-behind :
List<myControl> ctrls = new List<myControl>();
myControl ctr = LoadControl("~/Control.ascx") as myControl;
ctr.Name = ...
// ...
ctrls.Add(myControl); // add new control to the collection
And after, i bind this list to Gridview control :
this.GridView1.DataSource = ctrls;
this.gridView1.DataBind();
In the Page_Load event with condition If (!IsPostBack). This does not work: the representation of the object is displayed. Whereas when I put the controls in a Panel, all worked.

Don't use a GridView for this. Use a Repeater. And bind it to the data, not to list of controls. Example:
<asp:Repeater runat="server" id="ControlsRepeater">
<ItemTemplate>
<uc:MyControl runat="server" />
</ItemTemplate>
</asp:Repeater>
Code Behind
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack)
{
var myData=GetData(); //should return some type of ICollection representing your data to bind to
ControlsRepeater.DataSource=myData;
ControlsRepeater.DataBind();
}
}
If you want paging, then you should take advantage of lazy loading (the Entity Framework handles this for you if you use that) and the Linq functions .Take() and .Skip().

Edit row in gridview with hyperlink in ASP.NET

I've got a gridview displaying product instance info; I need a hyperlink in my Action column to bring up an view/edit page that displays the row data. How do I make the link bring up the data from that specific row into the edit page?
Note: there are other questions with similar titles, however, they do not cover this specific topic.

Use datakeys in the gridview, using datakey will get you the id of each clicked hyperlink , and then you can use that id to edit or delete the selected items easily. In the code behind just find the hyperlink control , pass the data key and write d update sql for it. Inorder to move your data to other pages you can sessions but if you are developing a commercial website session wont be a good idea due to its security issues, use cookies in that case .
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
if (Request.QueryString["productID"] != null)
{
productID = Convert.ToInt32(Request.QueryString["productID"]);
bindData(productID)
}
...
}
}
protected void bindData(int productID)
{
//to avoid sql injection as mentioned below use parameters
SqlConnection conn = new SqlConnection(ConnectionString); // define connection string globally or in your business logic
conn.Open();
SqlCommand sql = new SqlCommand("Select * From [Table] Where ID = #productID",conn);
SqlParameter parameter = new SqlParameter();
parameter.ParameterName = "#ID";
parameter.Value = productID;
sql.Parameters.Add(parameter);
conn.close()
}
You can also use Microsoft.ApplicationBlocks.Data.dll to avoid repeating ado.net , it will reduce your code.

Try something like this?
ViewProducts.aspx:
<columns>
<asp:HyperLinkField DataNavigateUrlFields="ProductID" HeaderText="Edit"
ItemStyle-Width="80"
DataNavigateUrlFormatString="EditProduct.aspx?productID={0}"
Text="Select" ItemStyle-HorizontalAlign="Center" />
...
</columns>
EditProduct.aspx:
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
if (Request.QueryString["productID"] != null)
{
productID = Convert.ToInt32(Request.QueryString["productID"]);
...
}
...
}
}

There are n+1 ways to solve this problem. If you are using the sql data source you can accentually have VS generate the sql and edit logic for you if you don't have specific requirements. here is a code project tutorial.
Another oft used tactic is to add a command button to the row and populate the command argument with the ID of the row you want to edit then in the oncommand event handle what ever logic you need.
you can also use a simple html link and and use get parameters. Or you can session like I said there a a ton of ways to solve this problem.

accessing gridview hiddenfield

' />
I want to access the value in the hidden field in my code behind. I know i need to do this when the item is bound but i cant seem to work out how to do it.
protected void addLabelsWhereNeeded(object sender, EventArgs e)
{
// Get Value from hiddenfield
}

Try adding
OnRowDataBound="addLabelsWhereNeeded"
to your GridView. Then cast the control in the corresponding cell to a HiddenField to grab the value:
protected void addLabelsWhereNeeded(object sender, GridViewRowEventArgs e)
{
HiddenField hf = e.Row.Cells[0].Controls[1] as HiddenField;
String theValue = hf.Value;
}
assuming you've defined your GridView as:
<asp:GridView runat="server" ID="gv" OnRowDataBound="addLabelsWhereNeeded">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<%--your hidden field--%>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
Just make sure you are indexing the correct cell and correct control within that cell.

yes you are right. You must do it on ItemDateBound. Check It must work

I do quite see what you want to achieve with this private field while databinding? In the RowDataBound Event you can access the whole data item, so there is no need for the use of a hidden value.
Pseudocode:
protected void Grid1_RowDataBound(object sender, GridViewRowEventArgs)
{
if(e.RowType == RowType.DataRow)
{
}
}
Set a Breakpoint into if clause and use quickwatch to see how you need to cast the DataItem that is currently bound to gain full access to all properties, even if they aren't bound to any control.