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Maintain sorting throughout paging in gridview in asp.net

How to maintain sorting throughout paging in gridview in asp.net.
Below is my code behind for binding grid, paging, and sorting
private string SortDirection
{
get { return ViewState["SortDirection"] != null ? ViewState["SortDirection"].ToString() : "ASC"; }
set { ViewState["SortDirection"] = value; }
}
private void BindGV(string sortExpression = null)
{
string CS = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
SqlConnection con = new SqlConnection(CS);
SqlCommand cmd = new SqlCommand("SPGetEmpDetailes", con);
cmd.CommandType = CommandType.StoredProcedure;
SqlDataAdapter sda = new SqlDataAdapter(cmd);
using (DataTable dt = new DataTable())
{
sda.Fill(dt);
if (sortExpression != null)
{
DataView dv = dt.AsDataView();
this.SortDirection = this.SortDirection == "ASC" ? "DESC" : "ASC";
dv.Sort = sortExpression + " " + this.SortDirection;
EmployeeGV.DataSource = dv;
}
else
{
EmployeeGV.DataSource = dt;
}
EmployeeGV.DataBind();
}
}
I am new to .NET and I want to maintain sorting throughout paging but I don't know how to do it.
protected void EmployeeGV_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
EmployeeGV.PageIndex = e.NewPageIndex;
BindGV();
}
protected void EmployeeGV_Sorting(object sender, GridViewSortEventArgs e)
{
this.BindGV(e.SortExpression);
}

Ok, so since we have a data pager here, then that means the data page routine will re-bind the GV. So, that means:
Loading up - first page load - we fill the grid
When we page - we fill the grid
When we sort - we fill the grid.
So, from above, we see at least 3 places. That suggests we need (and want) ONE routine to load up the grid - since we have several places where we will do this.
And I see you have one routine for this. We tweak it up a bit.
Next up:
The sort value we get/have does not persit, so once again we can use ViewState for that. (and again I see you attempting to use that).
So, lets lay this out.
First up, and NEVER forget this rule:
You want to load combo boxes, grids, listbox and ANY data on your FIRST page load, and ONLY your first page load, and ONLY first time. If you break this rule then you in effect cannot build a working web forms page - you just can't!!!!
And the reason is simple:
Any button click, any post-back, and any code operations on that page will ALWAYS and I repeat ALWAYS will trigger the page load event first and then YOUR event - (button click, paging or whatever). So, that means we ALWAYS will have our page load code stub and have a if (!IsPostBack) code stub - (darn near always follow this design pattern).
Ok, so lets code this up.
next up: I see no reason to put say a datatable in some using block - they safe dispose on their own. However, adopting using blocks for sql connections, and things like a sql command object - yes, do apply a using block.
Ok, I think we quite much cleared up the base issues.
So, lets setup the code, say like this:
So, say our simple markup - we dropped in a row select button.
<div style="padding:35px;width:55%">
<asp:GridView ID="GridView1" runat="server"
AutoGenerateColumns="False" DataKeyNames="ID" CssClass="table"
AllowPaging="True" OnPageIndexChanging="GridView1_PageIndexChanging" PageSize="8" AllowSorting="True" OnSorting="GridView1_Sorting">
<Columns>
<asp:BoundField DataField="FirstName" HeaderText="First" SortExpression="FirstName" />
<asp:BoundField DataField="LastName" HeaderText="Last" SortExpression="LastName" />
<asp:BoundField DataField="HotelName" HeaderText="HotelName" SortExpression="HotelName" />
<asp:BoundField DataField="City" HeaderText="City" SortExpression="City" />
<asp:BoundField DataField="Description" HeaderText="Description" SortExpression="Description" />
<asp:CheckBoxField DataField="Active" HeaderText="Active" ItemStyle-HorizontalAlign="Center" />
<asp:TemplateField>
<ItemTemplate>
<asp:Button runat="server" Text="View" CssClass="btn" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
<PagerStyle CssClass="GridPager" />
</asp:GridView>
</div>
Ok, now our code, say this:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
ViewState["MySort"] = "HotelName";
BindGV();
}
}
void BindGV()
{
using (SqlConnection conn = new SqlConnection(Properties.Settings.Default.TEST4))
{
using (SqlCommand cmdSQL = new SqlCommand("SELECT * FROM MyHotels", conn))
{
conn.Open();
DataTable rstData = new DataTable();
rstData.Load(cmdSQL.ExecuteReader());
// apply optional sort
if (ViewState["MySort"] != null)
rstData.DefaultView.Sort = ViewState["MySort"] as string;
GridView1.DataSource = rstData;
GridView1.DataBind();
}
}
}
protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
GridView1.PageIndex = e.NewPageIndex;
BindGV();
}
protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
{
ViewState["MySort"] = e.SortExpression;
BindGV();
}
And now we get this:
So, the trick or approach?
We have ONE view sate that holds our sort - when we want to sort, we simply put into this ViewState["MySort"] = some column to sort. After that, our bind + load routines are free to run - and we sort if set.
Thus, the pager routine, sort routine, and load routine -- they all call that one routine, and thus we don't have to write a lot of code.
And the view button? Well, if we click on that button (say we add a click event) like this:
Then the row button click can be this:
protected void Unnamed_Click(object sender, EventArgs e)
{
Button btn = sender as Button;
GridViewRow gRow = btn.NamingContainer as GridViewRow;
Debug.Print("Row index click = " + gRow.RowIndex.ToString());
// get database (hidden pk row id
int? PKID = GridView1.DataKeys[gRow.RowIndex]["ID"] as int?;
Debug.Print("Database PK = " + PKID.ToString());
Debug.Print("Hotel name this row = " + gRow.Cells[2].Text);
}
And clicking, we get:

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!

Click GridView Find Selected Row

I'm trying to take a GridView and get back the data from the row that was clicked. I've tried the code below and when I click the row I get back the selected index but when I look at the actual rows in the GridView they show empty. Not sure what I am missing.
.ASP make my grid.
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="True"
CssClass="datatables" Width="100%"
DataSourceID="SqlDataSource1"
GridLines="None" ShowFooter="True" AllowSorting="True"
onrowcreated="GridView1_RowCreated"
onrowdatabound="GridView1_RowDataBound" ShowHeaderWhenEmpty="True"
onrowcommand="GridView1_RowCommand"
onselectedindexchanged="GridView1_SelectedIndexChanged">
<HeaderStyle CssClass="hdrow" />
<RowStyle CssClass="datarow" />
<PagerStyle CssClass="cssPager" />
</asp:GridView>
On each row data bound I make sure that the click should set the selected index.
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
e.Row.Attributes["onclick"] = Page.ClientScript.GetPostBackClientHyperlink(GridView1, "Select$" + e.Row.RowIndex);
}
}
Then when the selected index changes by clicking this gets fired which I can put a breakpoint on the first line and I see the index of what I clicked on get stored in a. However when I get to the foreach it skips right past it because it shows GridView1 having a Count of 0 rows. In theory it should have a couple hundred rows and when the index matches it should grab the data in the 6th cell over and store it in string b. Why am I getting no rows on the click?
protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
{
int a = GridView1.SelectedIndex
foreach (GridViewRow row in GridView1.Rows)
{
if (row.RowIndex == a)
{
b = row.Cells[6].Text;
}
}
}
Here is my page load.
protected void Page_Load(object sender, EventArgs e)
{
c = HttpContext.Current.Session["c"].ToString();
SqlDataSource1.ConnectionString = //My secret
string strSelect = "SELECT columnnames from tablenames where c in (#c)
SqlDataSource1.SelectParameters.Clear();
SqlDataSource1.SelectCommand = strSelect;
SqlDataSource1.SelectParameters.Add("c", c);
try
{
GridView1.DataBind();
}
catch (Exception e)
{
}
GridView1.AutoGenerateColumns = true;
}

Try just grabbing the row from the SelectedRow property:
protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
{
GridViewRow row = GridView1.SelectedRow;
string b = row.Cells[6].Text;
}
It's my understanding that the Rows collection doesn't get repopulated on PostBacks when you're using those data source controls (like SqlDataSource).
You could probably use your existing code if you called .DataBind() on your GridView prior to trying to iterate through the Rows:
GridView1.DataSourceID="SqlDataSource1";
GridView1.DataBind();
But that seems a little hacky.
After seeing your Page_Load, I see that you need to wrap your databinding code in an if(!Page.IsPostBack) block. Databinding on every postback is interrupting the process of ASP.NET maintaining the state of your controls via the ViewState.

Databinding to a Hidden Aspxcombobox?

I have an aspxGridView control to list some records. I am using a combobox to fill some data, which is different from aspxgridview's .
protected void ASPxGridView1_CellEditorInitialize(object sender, ASPxGridViewEditorEventArgs e)
{
if (e.Column.FieldName == "LnkHotelID")
{
ASPxComboBox cmb = e.Editor as ASPxComboBox;
cmb.DataSource = DsHtel;
cmb.ValueField = "HotelID";
cmb.ValueType = typeof(Int32);
cmb.TextField = "HotelName";
cmb.DataBindItems();
}
}
I don't want to see "LnkHotelID" so I want it hidden. But when I hide this column, I can't use the function above. Also I want to see "HotelName" column but not to update it.
So I have two questions:
1) How can I access aspxcombobox at runtime?
2) How can I show my HotelName but not edit them?

Set the ASPxComboBox.ClientEnabled property to False:
ASPxComboBox cmb = e.Editor as ASPxComboBox;
cmb.ClientEnabled = false;

When you hide column with visible=false it will not render that in HTML so you can't use above function. So instead of visible false use style property with display: none
<style>
.hiddencolumn {display:none;}
</style>
<asp:GridView ID="GridViewHotel" runat="server" AutoGenerateColumns="false">
<Columns>
<asp:BoundField DataField="LnkHotelID" ItemStyle-CssClass="hidden"
HeaderStyle-CssClass="hiddencolumn" />
</Columns>
</asp:GridView>
Now you can use your code.

How to hide a column (GridView) but still access its value?

I have a GridView with a DataSource (SQL Database). I want to hide a column, but still be able to access the value when I select the record. Can someone show me how to do this?
This is the column I want to hide and still want to access its value:
<asp:BoundField DataField="Outlook_ID" HeaderText="OutlookID" />
I tried everything to hide the column (property Visible="false"), but I can't access its value.

<head runat="server">
<title>Accessing GridView Hidden Column value </title>
<style type="text/css">
.hiddencol
{
display: none;
}
</style>
<asp:BoundField HeaderText="Email ID" DataField="EmailId" ItemStyle-CssClass="hiddencol" HeaderStyle-CssClass="hiddencol" >
</asp:BoundField>
ArrayList EmailList = new ArrayList();
foreach (GridViewRow itemrow in gvEmployeeDetails.Rows)
{
EmailList.Add(itemrow.Cells[YourIndex].Text);
}

If I am not mistaken, GridView does not hold the values of BoundColumns that have the attribute visible="false". Two things you may do here, one (as explained in the answer from V4Vendetta) to use Datakeys. Or you can change your BoundColumn to a TemplateField. And in the ItemTemplate, add a control like Label, make its visibility false and give your value to that Label.

Define a style in css:
.hiddencol { display: none; }
Then add the ItemStyle-CssClass="hiddencol" and the HeaderStyle-CssClass="hiddencol" attribute to the grid field:
<asp:BoundField DataField="ID" HeaderText="ID" ItemStyle-CssClass="hiddencol" HeaderStyle-CssClass="hiddencol" ClientIDMode="Static" />

You can use DataKeys for retrieving the value of such fields, because (as you said) when you set a normal BoundField as visible false you cannot get their value.
In the .aspx file set the GridView property
DataKeyNames = "Outlook_ID"
Now, in an event handler you can access the value of this key like so:
grid.DataKeys[rowIndex]["Outlook_ID"]
This will give you the id at the specified rowindex of the grid.

You can do it programmatically:
grid0.Columns[0].Visible = true;
grid0.DataSource = dt;
grid0.DataBind();
grid0.Columns[0].Visible = false;
In this way you set the column to visible before databinding, so the column is generated.
The you set the column to not visible, so it is not displayed.

If you do have a TemplateField inside the columns of your GridView and you have, say, a control named blah bound to it. Then place the outlook_id as a HiddenField there like this:
<asp:TemplateField HeaderText="OutlookID">
<ItemTemplate>
<asp:Label ID="blah" runat="server">Existing Control</asp:Label>
<asp:HiddenField ID="HiddenOutlookID" runat="server" Value='<%#Eval("Outlook_ID") %>'/>
</ItemTemplate>
</asp:TemplateField>
Now, grab the row in the event you want the outlook_id and then access the control.
For RowDataBound access it like:
string outlookid = ((HiddenField)e.Row.FindControl("HiddenOutlookID")).Value;
Do get back, if you have trouble accessing the clicked row. And don't forget to mention the event at which you would like to access that.

You can make the column hidden on the server side and for some reason this is different to doing it the aspx code. It can still be referenced as if it was visible. Just add this code to your OnDataBound event.
protected void gvSearchResults_DataBound(object sender, EventArgs e)
{
GridView gridView = (GridView)sender;
if (gridView.HeaderRow != null && gridView.HeaderRow.Cells.Count > 0)
{
gridView.HeaderRow.Cells[UserIdColumnIndex].Visible = false;
}
foreach (GridViewRow row in gvSearchResults.Rows)
{
row.Cells[UserIdColumnIndex].Visible = false;
}
}

Leave visible columns before filling the GridView. Fill the GridView and then hide the columns.

Here is how to get the value of a hidden column in a GridView that is set to Visible=False: add the data field in this case SpecialInstructions to the DataKeyNames property of the bound GridView , and access it this way.
txtSpcInst.Text = GridView2.DataKeys(GridView2.SelectedIndex).Values("SpecialInstructions")
That's it, it works every time very simple.

I have a new solution hide the column on client side using css or javascript or jquery.
.col0
{
display: none !important;
}
And in the aspx file where you add the column you should specify the CSS properties:
<asp:BoundField HeaderText="Address Key" DataField="Address_Id" ItemStyle-CssClass="col0" HeaderStyle-CssClass="col0" > </asp:BoundField>

I used a method similar to user496892:
SPBoundField hiddenField = new SPBoundField();
hiddenField.HeaderText = "Header";
hiddenField.DataField = "DataFieldName";
grid.Columns.Add(hiddenField);
grid.DataSource = myDataSource;
grid.DataBind();
hiddenField.Visible = false;

I found this solution, an elegant(IMO) quick 2 parter.
1.
On your gridview, add a column as normal, no need to do anything differently:
<asp:BoundField DataField="AccountHolderName" HeaderText="Account Holder"
ReadOnly="true"/>
You can keep the header text if this is useful to you for later processing.
2.
In the rowdatabound method for the grid hide the header, footer and row for that column index:
if (e.Row.RowType == DataControlRowType.Header)
{
e.Row.Cells[10].Visible = false;
}
if (e.Row.RowType == DataControlRowType.Footer)
{
e.Row.Cells[10].Visible = false;
}
if (e.Row.RowType == DataControlRowType.DataRow)
{
e.Row.Cells[10].Visible = false;
}

You can do it code behind.
Set visible= false for columns after data binding .
After that you can again do visibility "true" in row_selection function from grid view .It will work!!

I searched a lot but no luck. The most of them was working with some errors. Finally I used this code and it worked for me.
probably you should change 1 to some other value. for me I would hide second col.
protected void FoundedDrGridView_RowDataBound(object sender, GridViewRowEventArgs e)
{
if(e.Row.RowType!=DataControlRowType.Pager)e.Row.Cells[1].Visible = false;
}

I just set the width to 0. and it works.
columns.AddFor(m => m.Id).Name("hide-id").Width(0);

When I want access some value from GridView before GridView was appears.
I have a BoundField and bind DataField nomally.
In RowDataBound event, I do some process in that event.
Before GridView was appears I write this:
protected void GridviewLecturer_PreRender(object sender, EventArgs e)
{
GridviewLecturer.Columns[0].Visible = false;
}