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
I have a repeater on my asp.net web forms page.
The repeater data source is a list of "OrderLine" objects.
Each repeater item has a TextBox control that displays the quantity of the order line.
When the quantity in the textbox control is changed, there is an auto postback to recalculate the total and discount value properties of the OrderLine object.
My question is, is there a better way to access the object data directly instead of getting the index of the repeater item and using that to get the object list index like below?
I'd like to access the object directly if possible rather than create temporary variables.
protected void txtLineQuantity_TextChanged(object sender, EventArgs e)
{
RepeaterItem rItem = (RepeaterItem)((Control)sender).NamingContainer;
int i = rItem.ItemIndex;
decimal netPrice = OrderLines[i].NetPrice;
decimal netTotal = OrderLines[i].NetTotal;
int qty = OrderLines[i].Quantity;
decimal weight = OrderLines[i].Weight;
TextBox txtLineQuantity = (TextBox)rItem.FindControl("txtLineQuantity");
//... do calculations and bind data to repeater control
}
If i've missed any info that's needed please let me know...
Thanks
You can add a HiddenField control to RepeaterItem. Bind data to HiddenField.
ASP
<asp:Repeater runat="server" ID="repeater">
<ItemTemplate>
<asp:HiddenField ID="hiddenNetPrice" runat="server" Value='<%# Eval("NetPrice") %>' />
<!--Other Controls
</ItemTemplate>
</asp:Repeater>
C#
RepeaterItem rItem = (RepeaterItem)((Control)sender).NamingContainer;
var hiddenNetPrice= rItem.FindControl("hiddenNetPrice") as HiddenField;
var netPrice = hiddenNetPrice.Value;
I've got a pretty strange problem with my usercontrols that I'm working with. I'm coding some user controls to be used in a DotNetNuke module.
Basically I have a UserControl on my page that holds some controls and then there is a Placeholder where I am loading in a UserControl that has a GridView placed in it.
Basically here is my page structure
<asp:Panel runat="server" ID="pnlServiceType" Visible="false">
<uc:ServiceType runat="server" ID="ServiceType" />
</asp:Panel>
Within that user control are some form elements and then the following:
<asp:PlaceHolder runat="server" ID="phServices" />
That placeholder then has a user control added to it like so:
<p class="header"><asp:Label runat="server" ID="lblServiceHeader" Font-Bold="true" /></p>
<asp:GridView runat="server" ID="gvServices" AlternatingRowStyle-BackColor="#eaeaea" BorderStyle="None" GridLines="None"
AutoGenerateColumns="false" CellPadding="6" Width="100%" EnableViewState="false" OnRowEditing="gvServices_RowEditing">
When the user picks something in the DropDownList, I'm clearing the controls out of the Placeholder, and re-adding just a single UserControl for the set of records for whatever type they've picked like so
_serviceID = e.Value;
//Clear the controls out of the placeholder
phServices.Controls.Clear();
//Reset the count of grids for the OnInit() method
Session["GridCount"] = 0;
if (e.Value != "NULL")
{
PopulateServicesGrid(_service.GetServicesByFormType(Convert.ToInt32(e.Value)));
}
else
{
PopulateServicesGrid(_service.GetServicesByClient(Convert.ToInt32(_client)));
}
And the PopulateServicesGrid method:
private void PopulateServicesGrid(List<NOAService> services)
{
//Creates a LINQ grouping based on the Billing Codes
//Allows a super easy creation of grids based on the grouped billing codes
var query = services.Select(service => service.BillingCode).Distinct();
foreach (string code in query)
{
var servicesByCode = services.Where(service => service.BillingCode == code).ToList();
ServicesGrid servicesGrid = LoadControl("~/DesktopModules/LEL Modules/NOA/ServicesGrid.ascx") as ServicesGrid;
Label lblServiceHeader = servicesGrid.FindControl("lblServiceHeader") as Label;
GridView gvServices = servicesGrid.FindControl("gvServices") as GridView;
phServices.Controls.Add(servicesGrid);
servicesGrid.ID = code;
lblServiceHeader.Text = servicesByCode[0].FormTypeName;
gvServices.DataSource = servicesByCode;
gvServices.DataBind();
Session["GridCount"] = phServices.Controls.Count;
}
}
And on my ServiceType UserControl, on the PageInit, I'm readding the ServiceGrid usercontrol so that my grids show up across postbacks and aren't lost from the Placeholder
void NOAServiceType_Init(object sender, EventArgs e)
{
for (int i = 0; i < Convert.ToInt32(Session["GridCount"]); i++)
{
ServicesGrid servicesGrid = LoadControl("~/DesktopModules/LEL Modules/NOA/ServicesGrid.ascx") as ServicesGrid;
phServices.Controls.Add(servicesGrid);
}
}
The grids populate successfully and everything seems to work just fine. But for some reason, on my GridView, I have a CommandField of
<asp:CommandField ShowEditButton="true" ItemStyle-HorizontalAlign="Right" EditText="Edit" UpdateText="Update"
EditImageUrl="~/images/LELModules/appbar.edit.rest.png" CancelImageUrl="~/images/LELModules/appbar.close.rest.png" UpdateImageUrl="~/images/LELModules/appbar.check.rest.png"
ButtonType="Image" CausesValidation="false" />
When I click my Edit command on the Grid row, nothing happens. My grid doesn't lose its rows, the control is still there, everything seems like it should be ok. The RowEditing event doesn't fire until I click it a second time.
Any idea why this might be occuring?
UPDATE: I've managed to figure out that my SelectedIndexChanged handlers are effectively resetting the DataSource on the Grid contained by the UserControl when they are readded to the PlaceHolder. When the CommandField (Edit) is clicked though, the Init fires for the UserControl that holds the placeholder
ServiceType UserControl < `Init` fires here
-Form elements
-Placeholder which holds
--UserControl with GridView
The Init method loads up new instances of the UserControl and adds them to the PlaceHolder, but the DataSource is null. With EnableViewState=true it looks like the data is still bound, but if I handle PreRender, I can see that the DataSource on my gvServices | null
Is it even possible to edit rows like this on a GridView that is being added dynamically to a PlaceHolder over and over?
FIXED I found out what the issue was after referring to this article
http://www.west-wind.com/weblog/posts/2006/Feb/24/Overriding-ClientID-and-UniqueID-on-ASPNET-controls
It got me thinking, what if the IDs were getting changed? The controls are way nested. So I went and put a watch on the GridView's ID, ClientID, and UniqueID just to see. When the Control is loaded on my Init handler, it's assigned a super generic ID when it's added.
private void PopulateServicesGrid(List<NOAService> services)
{
//Creates a LINQ grouping based on the Billing Codes
//Allows a super easy creation of grids based on the grouped billing codes
var query = services.Select(service => service.BillingCode).Distinct();
foreach (string code in query)
{
var servicesByCode = services.Where(service => service.BillingCode == code).ToList();
ServicesGrid servicesGrid = LoadControl("~/DesktopModules/LEL Modules/NOA/ServicesGrid.ascx") as ServicesGrid;
Label lblServiceHeader = servicesGrid.FindControl("lblServiceHeader") as Label;
GridView gvServices = servicesGrid.FindControl("gvServices") as GridView;
phServices.Controls.Add(servicesGrid);
**servicesGrid.ID = code;**
lblServiceHeader.Text = servicesByCode[0].FormTypeName;
gvServices.DataSource = servicesByCode;
gvServices.DataBind();
Session["GridCount"] = phServices.Controls.Count;
}
}
I was setting the ID as something else. So when I was hitting the Edit RowCommand on my grid, it was reloading the controls again on Init and the IDs were being changed back from my custom set code (T2020, pulled from my database) to the generic ID again, it didn't know how to fire the event.
I hope this helps someone as I've lost at least 12 hours fixing this problem.
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;
}
Hi I'm having a bit of an issue with a asp.net repeater
I'm building a categories carousel with the dynamic categories being output by a repeater.
Each item is a LinkButton control that passes an argument of the category id to the onItemClick handler.
a page variable is set by this handler to track what the selected category id is....
public String SelectedID
{
get
{
object o = this.ViewState["_SelectedID"];
if (o == null)
return "-1";
else
return (String)o;
}
set
{
this.ViewState["_SelectedID"] = value;
}
}
problem is that i cant seem to read this value while iterating through the repeater as follows...
<asp:Repeater ID="categoriesCarouselRepeater" runat="server"
onitemcommand="categoriesCarouselRepeater_ItemCommand">
<ItemTemplate>
<%#Convert.ToInt32(Eval("CategoryID")) == Convert.ToInt32(SelectedID) ? "<div class=\"selectedcategory\">":"<div>"%>
<asp:LinkButton ID="LinkButton1" CommandName="select_category" CommandArgument='<%#Eval("CategoryID")%>' runat="server"><img src="<%#Eval("imageSource")%>" alt="category" /><br />
</div>
</ItemTemplate>
</asp:Repeater>
calling <%=SelectedID%> in the item template works but when i try the following expression the value of SelectedID returns empty..
<%#Convert.ToInt32(Eval("CategoryID")) == Convert.ToInt32(SelectedID) ? "match" : "not a match"%>
the value is being set as follows...
protected void categoriesCarouselRepeater_ItemCommand(object source, RepeaterCommandEventArgs e)
{
SelectedID = e.CommandArgument.ToString();
}
Any ideas whats wrong here?
Within the categoriesCarouselRepeater_ItemCommand code you've shown, you're assigning the CommandArgument to a property called 'SelectedCategory'.
Should this not be assigning the property to the 'SelectedID' property instead?
** EDIT..
The problem I see is one of two scenarios:
1) You are not rebinding the repeater with each postback, and therefore the expression within your ItemTemplate is not being evaluated - The output from the repeater will remain unchanged with each postback.
OR
2) You are rebinding the repeater control with each postback, however, upon clicking on your LinkButton for the first time, the repeater control is re-binded PRIOR to the ItemCommand event handler firing, and therefore, the 'SelectedID' property has not been set until after the repeater has finished being output.
If you were to click on one of your LinkButtons a 2nd time, the previously selected ID would be in viewstate at the time of the repeater control contents being rendered, and therefore be one step behind in rendering which category has been clicked, and so on...