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Run an event when Checkbox is Checked/Unchecked Gridview C#

I have a Gridview that has 4 columns. All in ItemTemplate One column is a CheckBox. This Gridview is binded to a datasource. What I want to do is when the Checkbox is checked update the database with the bit value '1' and if I uncheck the Checkbox to do the same but '0'.
I already know my SQL code to update the database, but I am not sure how to run the event so that it looks at the current row the checkbox is on in the gridview.
Here is the CheckBox Column.
<asp:TemplateField HeaderText="Pick" ItemStyle-CssClass="hrGrid" HeaderStyle-CssClass="hdrHrBase">
<ItemTemplate>
<asp:CheckBox id="cbViewCustomer" runat="server" OnCheckedChanged="ViewCustomer" onAutoPostBack="true" Checked='<%#(Eval("chosen"))%>'/>
</ItemTemplate>
</asp:TemplateField>
Do I use EventArgs like this:
The problem with this is it updates the database but all the rows.
What I am trying to do is update only the current row that is in the Gridview. I am just not sure where to go from here.
protected void ViewCustomer(object sender, EventArgs e)
{
string SelectCustomer = "UPDATE tblcustomer Set chosen ='0'";
NpgsqlCommand changedata = new NpgsqlCommand(SelectCustomer, con);
con.Open();
changedata.ExecuteNonQuery();
con.Close();
}
Or should I be doing something different?

You can do this with OnRowCommand event of gridview like this:-
Associate a RowCommand event with your gridview:-
<asp:GridView ID="mygridview" runat="server" OnRowCommand="mygridview_OnRowCommand">
Next, associate a CommandName & CommandArgument to your checkbox:-
<asp:TemplateField HeaderText="Pick" ItemStyle-CssClass="hrGrid" >
<ItemTemplate>
<asp:CheckBox id="cbViewCustomer" runat="server" Checked='<%#(Eval("chosen"))%>'
CommandName="myCheckbox" CommandArgument="<%# Container.DataItemIndex %>"/>
</ItemTemplate>
</asp:TemplateField>
In the code behind handle the event:-
protected mygridview_OnRowCommand (object sender, GridViewCommandEventArgs e)
{
if(e.CommandName == "myCheckbox")
{
int rowIndex = Convert.ToInt32(e.CommandArgument);
GridViewRow row = mygridview.Rows[rowIndex];
bool ischecked = (row.FindControl("cbViewCustomer") as CheckBox).Checked;
}
}
You can also do it with checbox checked event, but if you have multiple controls then fire the gridview command event instead of individual events.

Nesting Gridview inside Formview breaks insert codebehind context

I have a couple of GridViews in my FormView page and I am wanting to make an Insert row in the FooterRow of the Gridviews. Layout and everything is fine. However, as I'm building the codebehind for the Insert command, I'm running into a context problem. If I move the GridView outside of the FormView markup, the context errors clear up immediately.
GridView Markup
<asp:GridView ID="gvBFMats" runat="server" ShowFooter="True" AutoGenerateColumns="False" DataKeyNames="MaterialID" DataSourceID="BFMatsSQL" OnRowCommand="gvBFMats_RowCommand">
<Columns>
<asp:TemplateField HeaderText="Commands" ShowHeader="False">
<EditItemTemplate>
<asp:LinkButton ID="ButtonUpdate" runat="server" CausesValidation="True" CommandName="Update" Text="Update"></asp:LinkButton>
<asp:LinkButton ID="LinkButton2" runat="server" CausesValidation="False" CommandName="Cancel" Text="Cancel"></asp:LinkButton>
</EditItemTemplate>
<ItemTemplate>
<asp:LinkButton ID="ButtonEdit" runat="server" CausesValidation="False" CommandName="Edit" Text="Edit"></asp:LinkButton>
<asp:LinkButton ID="ButtonDelete" runat="server" CausesValidation="False" CommandName="Delete" Text="Delete"></asp:LinkButton>
</ItemTemplate>
<FooterTemplate>
<asp:LinkButton ID="ButtonAdd" runat="server" CommandName="Insert" Text="Add to Table" />
</FooterTemplate>
...
Insert Command Codebehind
protected void gvBFMats_RowCommand(object sender, GridViewCommandEventArgs e)
{
if (e.CommandName == "Insert" && Page.IsValid)
{
BFMatsSQL.Insert();
}
}
protected void BFMatsSQL_Inserting
(object sender, ObjectDataSourceMethodEventArgs e)
{
DropDownList ddlNewMfr =
(DropDownList)gvBFMats.FooterRow.FindControl("ddlNewMfr");
DropDownList ddlNewThickness =
(DropDownList)gvBFMats.FooterRow.FindControl("ddlNewThickness");
DropDownList ddlNewCore =
(DropDownList)gvBFMats.FooterRow.FindControl("ddlNewCore");
DropDownList ddlNewSize =
(DropDownList)gvBFMats.FooterRow.FindControl("ddlNewSize");
TextBox txtNewColor =
(TextBox)gvBFMats.FooterRow.FindControl("txtNewColor");
TextBox txtNewQty =
(TextBox)gvBFMats.FooterRow.FindControl("txtNewQty");
DropDownList ddlNewFinish =
(DropDownList)gvBFMats.FooterRow.FindControl("ddlNewFinish");
TextBox txtNewExtra =
(TextBox)gvBFMats.FooterRow.FindControl("txtNewExtra");
// Set the SQLDataSource's InsertParameters values
e.InputParameters["MatManufacturerID"] =
Convert.ToInt32(ddlNewMfr.SelectedValue);
e.InputParameters["MatThicknessID"] =
Convert.ToInt32(ddlNewThickness.SelectedValue);
e.InputParameters["MatCoreID"] =
Convert.ToInt32(ddlNewCore.SelectedValue);
e.InputParameters["MatSizeID"] =
Convert.ToInt32(ddlNewSize.SelectedValue);
e.InputParameters["MatFinishPrePostID"] =
Convert.ToInt32(ddlNewFinish.SelectedValue);
string strNewColor = null;
if (!string.IsNullOrEmpty(txtNewColor.Text))
strNewColor = txtNewColor.Text;
e.InputParameters["MatFinishColor"] = strNewColor;
int? intNewQty = null;
if (!string.IsNullOrEmpty(txtNewQty.Text))
intNewQty = Convert.ToInt32(txtNewQty.Text);
e.InputParameters["MatQty"] = intNewQty;
string strNewExtra = null;
if (!string.IsNullOrEmpty(txtNewExtra.Text))
strNewExtra = txtNewExtra.Text;
e.InputParameters["MatNumExtraSheets"] = strNewExtra;
}
Specifically, I get the red squiggly under the gvBFMats in the (Control)gvBFMats.FooterRow.FindControl("Control ID"); that says "The name 'gvBFMats' does not exist in the current context." I'm only guessing that it doesn't like the call to the GridView when it's nested inside a FormView template. Is there a way to pass this context along programatically?

You're right about it not recognizing the name gvBFMats because it's embedded in a template. Only "top-level", non-embedded controls will be treated in Code Behind as if they had been explicitly declared. Controls declared in a template will not. The compiler doesn't recognize those names.
There's a reason for this. Imagine you have a control called TextBox1 in one of the ItemTemplates for a repeating control. You bind it. Your page's control tree now has dozens of controls with the ID TextBox1. If you want to refer to TextBox1, how does it know which one you mean?
So. What can you do in your situation? Well, BFMatsSQL_Inserting and gvBFMats_RowCommand are both event handlers, so you can't change their signatures.
But, you can make use of them belonging to the same class, and use a module-level variable to hold the reference to gvBFMats. Like this:
private GridView gvBFMats;
protected void gvBFMats_RowCommand(object sender, GridViewCommandEventArgs e)
{
gvBFMats = [your form view].Row.FindControl("gvBFMats") as GridView;
if (e.CommandName == "Insert" && Page.IsValid)
{
BFMatsSQL.Insert();
}
}
Now, BFMatsSQL_Inserting will be able to refer to gvBFMats, and it should have a value.

Getting Gidview Hidden field value on button click in ASP.NET

I have a Gridview dtAppend. I want that when I press delete button the selected row record should be deleted from users table.
I first used button field in gridview, as:
<asp:ButtonField Text="Delete" CommandName="DeleteRow" ControlStyle-CssClass="btn btn-danger btn-small" ControlStyle-ForeColor="White" />
<asp:TemplateField visible="false" ItemStyle-Width="0px">
<ItemTemplate>
<asp:HiddenField ID="HiddenField" Visible="false" runat="server" Value='<%# Eval("userId") %>' />
</ItemTemplate>
</asp:TemplateField>
My client says to show JavaScript alert and on clicking yes the record should be deleted. I cannot write onClientClick for button field so I am being forced to use normal Asp button.
on rowCommand of gridview I am getting the hidden field value in this code
if (e.CommandName == "DeleteRow")
{
GridViewRow row = dtAppend.Rows[Convert.ToInt32(e.CommandArgument)];
hidden1 = (HiddenField)row.Cells[6].FindControl("HiddenField");
string text = Convert.ToString((HiddenField)row.Cells[6].FindControl("HiddenField"));
Session["dtIdDel"] = hidden1.Value;
}
i am getting thew value in Session but i need above code working Button_ClickEvent like below
protected void deleteButton_Click(object sender, EventArgs e)
{
GridViewRow row = dtAppend.Rows[Convert.ToInt32(e.CommandArgument)];
hidden1 = (HiddenField)row.Cells[6].FindControl("HiddenField");
string text = Convert.ToString((HiddenField)row.Cells[6].FindControl("HiddenField"));
Session["dtIdDel"] = hidden1.Value;}
this is where 'e.CommandArgument' gives Error
I cannot use the above code in normal button click as it gives error in e.CommandArgument
Any help?

Simply you can remove visible="false"
<asp:HiddenField ID="HiddenField" runat="server" Value='<%# Eval("userId") %>' />

You Better Remove Visible="false" . Because, the value that has to be binded for hidden field will not be binded in to the field if Visible="false" is there. Any how its a hidden field, so make it Visible="true"
EDIT :
How you handled the RowDataBound event of the Grid, are you assigning the CommandArgument for each row, other wise the above concept will not work in Paging. Refer as below
Ex : -
Button btnMail = (Button)e.Row.FindControl("lnkMail");
btnMail.CommandArgument = e.Row.RowIndex.ToString();

I think this would be easy way, instead of using hidden field.
<asp:LinkButton CommandArgument='<%# Eval("userId") %>' OnClientClick="if (!confirm('Are you sure you want delete?')) return false;" CommandName="DeleteRow" ID="eliminar" runat="server" Text="delete"/>
if (e.CommandName == "DeleteRow")
{
int userId = Int32.Parse(e.CommandArgument.ToString());
}

You can simply send ID as command argument
or
Try the code as below:
var ID = int.Parse(((HiddenField)item.FindControl("HiddenField1")).Value);
sql = "delete from tablename where id=" + ID;

Programmatically access GridView columns and manipulate

I have a GridView :
<asp:GridView ID="GridView1" runat="server" AllowPaging="True" GridLines="None"
HorizontalAlign="Left" AutoGenerateColumns="False"
DataSourceID="SqlDataSource1" onrowcommand="GridView1_RowCommand1">
<HeaderStyle HorizontalAlign="Left" />
<Columns>
<asp:TemplateField HeaderStyle-Width="150">
<HeaderTemplate>
<b>Downloads</b>
</HeaderTemplate>
<ItemTemplate>
<!-- <asp:HyperLink ID="hyperlinkDownload" runat="server" NavigateUrl="" >Download
MP3</asp:HyperLink> -->
<asp:LinkButton CommandName="download"
CommandArgument='<%# Eval("Name") %>' runat="server">Download MP3</asp:LinkButton>
</ItemTemplate>
</asp:TemplateField>
</asp:GridView>
I want to query the value of a particular field in a DB and if it's true, display the LinkButton. if false, I want the linkButton not to be displayed.
is there a way to access the GridView programmatically and make visible certain of its columns or manipulate its items ?
help.

You can do this by adding a handler to the RowDataBound event. Add an event handler along this lines of this in your code behind:
protected void myGrid_RowDataBound(Object sender, GridViewRowEventArgs e)
{
var data = e.Row.DataItem as DataRowView;
if (data != null)
{
var lbtDownload = e.Row.FindControl("lbtDownload");
lbtDownload.Visible = (bool) data.Row["HasFileForDownload"];
}
}
In your markup, attach the event handler to the grid:
<asp:GridView OnRowDataBound="myGrid_RowDataBound" ...>
You will also need to assign an id to the LinkButton, matching the one that you are search for using the FindControl() method in the event handler.
Disclaimer: I am on currently a Linux machine with no chance of testing this. Please report any bugs in the code - feel free to correct them if you have editor rights.

Yes there is.
1) You need to subscribe the RowDataBound event.
2) Give the LinkButton an ID.
3) Insert in codebehind
protected void GridView1_RowDataBound(Object sender, GridViewRowEventArgs e)
{
if(e.Row.RowType == DataControlRowType.DataRow)
{
LinkButton _bt = e.Row.FindControl("ID") as LinkButton;
if(_bt != null)
{
// have a look at the e.row.DataItem and try to get the value of your desired visibility property
_bt.Visible = true;
}
}
}
4) If this does not work with accessing the DataItem, start thinking about a LinqDataSource.

Get the Current Selected Row of GridView on a button Click

I want to fetch the DataKey of the Selected Row of GridView on button click.

I would Personal do it in a Template Field Like so:
<asp:TemplateField>
<ItemTemplate>
//EDIT: after a comment it is suggested that you pass the RowIndex as the command argument which would provide access to the entire row
<asp:LinkButton ID="btnCopy" runat="server"CausesValidation="False"CommandName="MyCommandButton"CommandArgument='<%# Eval("MyDataKeyOrWhateverIWanteverIWantFromTheBindingSource")%>'>
</ItemTemplate>
</asp:TemplateField>
CodeBehind
protect void MyCommandButton(Object sender,CommandArgument e)
{
int DataKeyOrPK=int32.Parse(e.CommandArgument.ToString());
}
You other option would be:
<asp:gridview id="myGrid" runat="server"
width=100% datakeynames="Myid"
autogeneratecolumns=false
onSelectedIndexChanged="MyEvent">
<asp:templatefield headertext="Choose your dream home">
<itemtemplate>
<asp:linkbutton runat="server" commandname="select" text='<%# Eval ( "Whatever" ) %>' />
</itemtemplate>
</asp:templatefield>
Note the commandname="select" above.
Data-bound controls recognize certain command names and automatically raise and handle the appropriate events for the control. The following command names are recognized:
Cancel, Delete, Edit, Insert, New, Page, Select, Sort and Update. Reference
Codebehind
private void MyEvent(Object sender, EventArgs e)
{
string id = myGrid.SelectedDataKey.Value.ToString();
}

Use the SelectedDataKey property of the GridView:
DataKey currentKey = myGridView.SelectedDataKey;