Develop Reference

dealing with GridView and Custom Validation, both client and serverside

I'm not quite sure how to solve this problem.
What I'm trying to do:
Go through a gridview with multiple rows, and force the user to enter in specific values if certain textboxes or drop down lists are left on the default value.
What I tried:
Tried client side requirements, by use of the focusout event in javascript. Focus goes onto these fields depending on the previous selections users make, that part works. My code:
var row = $(this).closest('tr');
var text = $(row).find("input[name*='txtCurriculum']").val('enter lesson/unit name here');
var ddl = $(row).find("select[name*='ddlCurrAdditions']");
$(ddl).focusout(function () {
if (ddl.val == "-select curriculum name-") {
$(ddl).focus();
alert("select a curriculum name before moving on");
}
});
$(text).focusout(function () {
if (text.val == 'enter lesson/unit name here') {
$(text).focus();
alert('enter in a lesson or unit name before moving on');
}
});
It never fired properly. the ddl focusout would fire, but wouldn't stop firing until I exited and went back to the page. the text focusout would never fire.
Tried server side validation, with the custom validation feature.
protected void cv1_ServerValidate(object source, ServerValidateEventArgs args)
{
CustomValidator cv = ((CustomValidator)(source));
GridViewRow gvr;
//if (FormCGrid.Rows)
foreach (GridViewRow row in FormCGrid.Rows)
{
//string ddl = ((DropDownList)row.FindControl("ddlCurrAdditions")).SelectedItem.Text;
string txtC = ((TextBox)row.FindControl("txtCurriculum")).Text;
bool ddl = ((DropDownList)row.FindControl("ddlCurrAdditions")).Visible;
if (txtC == "enter lesson/unit name here")
{
args.IsValid = false;
cv.ErrorMessage = string.Format("Please enter the Additional program name on row {0}", row.RowIndex);
}
else if (ddl == true)
{
cv.ErrorMessage = string.Format("Enter your lesson or unit for the curriculum selected on row {0}", row.RowIndex);
args.IsValid = false;
}
}
}
I tried to loop through the rows of the gridview here, checking the named dropdown for visibility (hidden until another dropdownlist reveals it, dependent on the value chosen there) and the textbox for the default value, yet this did not work either. It never fired at all. Any suggestions welcome.
I am generally ok with most programming/coding issues, but I find that working with the asp.net gridview, all of my techniques get thrown out the window.

Ok, there are two ways to do this, and you can use js quite easy here. However, lets go with a 100% server side code. I think sticking to server side code is easier.
Next up? I actually STONG suggest to use a listview in place of a gridview WHEN you plan to edit data. The reason is simple - the ListView does not require those "irratating" "item template" over and over for each asp.net control you want to drop/have in that grid display. Now to be fair, say 2-3 controls - then grid view is ok, but for more, then I really find that the listview starts to win here big time (no need for the item template).
The "trick" with listview is of course to setup a datasoruce on the web page, let it generate the markup, and then blow out (delete) all templates except for the item template. And then delete the datasourc1 item on the page, and remove the datasource1 setting from the list view.
However, lets go with the grid view - this will thus be some what "more messy"
So, we going to fill out the grid - and say we want a city combo box - MUST be selected. And lets toss in a basic check for say LastName also must be entered.
So, we have a city combo box (database driven). And say lets toss in a drop down for a hotel rating (1-5) - but that's only 5 choices - so we have that dropdown with the list in mark-up. (so two combo examples to show how this works).
So, say we have a grid like this, and we hit save, we get this result:
Now, of course we would fancy up that message box area. And in fact, we could VERY easy drop in jQuery.UI and make that cute div on the right appear in a dialog box (and we can trigger that box + jQuery.UI dialog display even from our server side code behind - but lets try and keep this short - but I would fancy up that error message area).
Ok, first the markup:
Just a simple grid, but "a bit messy" due to those "item Templates - (if you not figured this out, I really dislike those template things!!! - and with listview you don't need them!! - just drop in pure clean asp.net controls for the grid). Anyway:
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="ID">
<Columns>
<asp:BoundField DataField="ID" HeaderText="ID" InsertVisible="False" ReadOnly="True" SortExpression="ID" />
<asp:TemplateField HeaderText="HotelName" >
<ItemTemplate><asp:TextBox id="HotelName" runat="server" Text='<%# Eval("HotelName") %>' /></ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="FirstName" >
<ItemTemplate><asp:TextBox id="FirstName" runat="server" Text='<%# Eval("FirstName") %>' /></ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="LastName" >
<ItemTemplate><asp:TextBox id="LastName" runat="server" Text='<%# Eval("LastName") %>' /></ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="City">
<ItemTemplate>
<asp:DropDownList ID="cboCity" runat="server" DataTextField="City"
DataValueField = "City" Width="110px">
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Active">
<ItemTemplate><asp:CheckBox id="Active" runat="server" Checked = '<%# Eval("Active") %>' /></ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Rating">
<ItemTemplate>
<asp:DropDownList ID="cboRating" runat="server" SelectedValue = '<%# Eval("Rating") %>' >
<asp:ListItem Value="1">Poor</asp:ListItem>
<asp:ListItem Value="2">Just Ok</asp:ListItem>
<asp:ListItem Value="3">Ok</asp:ListItem>
<asp:ListItem Value="4">Good</asp:ListItem>
<asp:ListItem Value="5">Excellent</asp:ListItem>
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
</div>
<div id="ErrorDialog" style="display:normal;float:left;padding-left:30px;width:20%" runat="server">
<asp:TextBox ID="txtErrors" runat="server" TextMode="MultiLine" Style="width:100%" Rows="20" ></asp:TextBox>
</div>
<div style="clear:both;padding-top:20px">
<asp:Button ID="cmdSave" runat="server" Text="Save" />
<asp:Button ID="cmdUnDo" runat="server" Text="UnDo" Style="margin-left:20px"/>
</div>
Ok, now on SO? Gee, that is about the total max markup I would post in one shot - beyond above, we approach the "not very nice" post territory.
Ok, so lets look at the code to load up this grid. We have this code:
public class EditHotelsG : System.Web.UI.Page
{
private DataTable rstTable = new DataTable();
private DataTable rstCity = new DataTable();
protected void Page_Load(object sender, System.EventArgs e)
{
if (System.Web.UI.Page.IsPostBack == false)
{
ErrorDialog.Visible = false;
LoadGrid();
ViewState["rstTable"] = rstTable;
ViewState["rstCity"] = rstCity;
}
else
{
rstTable = ViewState["rstTable"];
rstCity = ViewState["rstCity"];
}
}
public void LoadGrid()
{
// load up our drop down list from database (city)
string strSQL;
strSQL = "SELECT City from tblCity Order by City";
using (SqlCommand cmdSQL = new SqlCommand(strSQL, new SqlConnection(My.Settings.TEST3)))
{
cmdSQL.Connection.Open();
rstCity.Load(cmdSQL.ExecuteReader);
// now load up main grid view
strSQL = "SELECT ID, FirstName, LastName, HotelName, City, Active, Rating from tblHotels ORDER BY HotelName";
cmdSQL.CommandText = strSQL;
rstTable.Load(cmdSQL.ExecuteReader);
GridView1.DataSource = rstTable;
GridView1.DataBind();
}
}
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
// set combo box data source
if (e.Row.RowType == DataControlRowType.DataRow)
{
// setup city drop down list
DropDownList cboDrop = e.Row.FindControl("cboCity");
cboDrop.DataSource = rstCity;
cboDrop.DataBind();
cboDrop.Items.Insert(0, new ListItem(string.Empty)); // add blank row
cboDrop.Text = rstTable.Rows(e.Row.RowIndex).Item("City").ToString;
}
}
}
Ok, now that is not all that much code. And a good part was setting up that combo box. Since the cbo box (dropdown list) was database driven, then we have to bind + setup for each row. So, that cost us a good chunk of our coding time.
Note however how we persist the database soruce (table). We do that, since we want to with A LOT LESS code, update the whole database behind in ONE shot. By peristing that table, then we
Transfer data from Grid to table
Save the table to database in one shot
So, this reduces our coding efforts by a truckload.
The code to save our data, thus becomes this gem:
(and note how we ALSO put in our validation code).
protected void cmdSave_Click(object sender, EventArgs e)
{
// pull gride rows back to table.
bool bolDataOk = true;
txtErrors.Text = "";
foreach (GridViewRow rRow in GridView1.Rows)
{
int RecordPtr = rRow.RowIndex;
DataRow OneDataRow;
OneDataRow = rstTable.Rows(RecordPtr);
OneDataRow.Item("HotelName") = rRow.FindControl("HotelName") as TextBox.Text;
OneDataRow.Item("FirstName") = rRow.FindControl("FirstName") as TextBox.Text;
OneDataRow.Item("LastName") = rRow.FindControl("LastName") as TextBox.Text;
OneDataRow.Item("City") = rRow.FindControl("cboCity") as DropDownList.Text;
OneDataRow.Item("Active") = rRow.FindControl("Active") as CheckBox.Checked;
OneDataRow.Item("Rating") = rRow.FindControl("cboRating") as DropDownList.SelectedValue;
// check for missing City, or LastName
if (IsDBNull(OneDataRow("City")) | OneDataRow("City") == "")
{
bolDataOk = false;
if (txtErrors.Text != "")
txtErrors.Text += Constants.vbCrLf;
txtErrors.Text += "Missing City on row = " + (rRow.RowIndex + 1).ToString;
}
if (IsDBNull(OneDataRow("LastName")) | OneDataRow("LastName") == "")
{
bolDataOk = false;
if (txtErrors.Text != "")
txtErrors.Text += Constants.vbCrLf;
txtErrors.Text += "Missing lastName on row = " + (rRow.RowIndex + 1).ToString;
}
}
ErrorDialog.Visible = !(bolDataOk);
// now send table back to database with updates
if (bolDataOk)
{
string strSQL = "SELECT ID, FirstName, LastName, City, HotelName, Active, Rating from tblHotels WHERE ID = 0";
using (SqlCommand cmdSQL = new SqlCommand(strSQL, new SqlConnection(My.Settings.TEST3)))
{
cmdSQL.Connection.Open();
SqlDataAdapter daupdate = new SqlDataAdapter(cmdSQL);
SqlCommandBuilder cmdBuild = new SqlCommandBuilder(daupdate);
daupdate.Update(rstTable);
}
}
}
Now, once again, that above code snip is a wee bit long - and is aobut the max size of a code snip for SO. I would perhaps consider breaking out that above last code into 2 or even 3 routines.
but, all in all, the above shows quite a few tricks, and approaches here.
As noted, I was going to post how you can/could verify using client side code, ,but the OVER ALL idea of saving back the whole grid with one database update? Well, I would use that trick with a listview, gridview, and even if I was doing client side js verification? I will still use the bulk of the above design pattern.
And the un-do button? Well, I never finished that part - but it would just call the same code as the first page load (postback - false, and you would simply re-bind the grid from the database source for the un-do button.

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 table row count not getting incremented

I have an ASP table, with a dropdownlist and text box in its 1st row. I have a button on click of which a similar row should be added. I have the following function in its button click event.
public void addRow()
{
int flag = Table1.Rows.Count;
DropDownList ddl = new DropDownList();
ddl.ID = "ddl" + (flag + 1).ToString();
TextBox tBox = new TextBox();
tBox.ID = "txt" + (flag + 1).ToString();
TableCell tCell1 = new TableCell();
TableCell tCell2 = new TableCell();
tCell1.Controls.Add(ddl);
tCell2.Controls.Add(tBox);
TableRow tRow = new TableRow();
tRow.Cells.Add(tCell1);
tRow.Cells.Add(tCell2);
Table1.Rows.Add(tRow);
}
This code works fine when adding 2nd row. When I click the button again, the value of flag which should have the value of number of rows of the table is not getting incremented. So a new row doesn't get created. Can you please tell me why the value of flag doesn't get incremented ? Or is their an easier way to do this ? Direct answer or link would be helpful.
Mark up code for Table:
<asp:Table ID="Table1" runat="server" Width="410px">
<asp:TableRow>
<asp:TableCell>
<asp:DropDownList runat="server" ID="ddl1"></asp:DropDownList>
</asp:TableCell>
<asp:TableCell>
<asp:TextBox runat="server" ID="txt1"></asp:TextBox>
</asp:TableCell>
</asp:TableRow>
</asp:Table>

Warning - Big ugly block of text
I'm going to try and explain why what you're trying to do is not as simple as it sounds (or as simple as I'd like it to be) and hopfully give you an alterantive approach, which while it
may not be straight forward, it should be "better".
It looks a high level overview of what you are trying to do is the following:
Give the user the oppotunity to add one or more records to a collection (database) before finalising the save.
It is possible to do this using postback to generate the additional rows/items beofore clicking the final save button. Hover this may not be the easiest, or best, way to do this.
From a technical viewpoint adding dynamic controls has to be handeld in a very specific manner at a specific point in the ASP.net page lifecylce. Dynamic controls also have to be recreated on every post back, so every time a user clicks the "add" button, you will have to re-reate the rows you already have in addition to the new row. This is why you only get the one row in this example. Thats just the adding of the dynaimc controls. Wait till you get to getting data from your dynamic text boxes and drop downs!
From an end users perspective, this approach is also not ideal as every time the user clicks the "add" button the page cycles through the request/response process, which at the minumun cuases a bit of an ugly flash.
Update
But how? I hear you ask. Well here it is (I've simplified it to one column for this example):
ASPX
<asp:Table ID="Table1" runat="server">
<asp:TableRow>
<asp:TableCell><asp:TextBox ID="txt1" runat="server"> </asp:TextBox></asp:TableCell>
</asp:TableRow>
</asp:Table>
<asp:Button ID="btnAdd" runat="server" Text="Add" onclick="Button1_Click" />
<asp:HiddenField ID="hdnRowCount" runat="server" />
<asp:Button ID="btnSave" runat="server" onclick="btnSave_Click" Text="Save" />
<div>
<asp:Label ID="lblResult" runat="server" Visible="false"></asp:Label>
</div>
C#
private int rowCount = 1;
private bool rowNeeded = false;
protected override void OnPreInit(EventArgs e)
{
//Pre-emptively create additional row on post back.
//We'll remove it if we don't need it later
//Controls Have to be added at pre-init to maintain their view state
//Adding a row in the button click event will result in any data
//entered in that row dissapearing from viewstate on next post back
if (IsPostBack)
{
//Get number of additional rows from hidden field
//We're using a hidden form field and Request.Form
//instead of ViewsState and hdnRowCount.value
//because ViewState has not been loaded at this stage
//of the page life cycle
if (!string.IsNullOrEmpty(Request.Form["hdnRowCount"]))
{
rowCount = int.Parse(Request.Form["hdnRowCount"]);
}
for (int i = 0; i < rowCount; i++)
{
TableRow tr = new TableRow();
TableCell tc = new TableCell();
TextBox tb = new TextBox();
// +2 as there are existing controls with "1", eg txt1
tb.ID = string.Format("txt{0}",i+2);
tc.Controls.Add(tb);
tr.Cells.Add(tc);
Table1.Rows.Add(tr);
}
}
base.OnPreInit(e);
}
//Add Row Click
protected void Button1_Click(object sender, EventArgs e)
{
//Hold number of additional rows in hidne field
hdnRowCount.Value = (++rowCount).ToString();
//Let the page know we need to keep the row
rowNeeded = true;
}
//An Exmple of how to get your data out
protected void btnSave_Click(object sender, EventArgs e)
{
string s = "";
//Iterate through the table rows finding the controls
//Using count -1 as we still have the pre-emptive row
for(int i = 0; i < Table1.Rows.Count-1; i++)
{
TextBox tb = (TextBox)Table1.Rows[i].FindControl(string.Format("txt{0}",i+1));
s += "," + tb.Text;
}
lblResult.Text = s;
lblResult.Visible = true;
}
protected override void OnLoadComplete(EventArgs e)
{
//Get rid of pre-emptive row if we don't need it
if (IsPostBack)
{
if (!rowNeeded)
{
Table1.Rows.RemoveAt(Table1.Rows.Count - 1);
}
}
base.OnLoadComplete(e);
}
End Update
So, how would I do it? Client side, is the answer to that question. I would use jQuery to create a clone of the first row. You then would need to adjust the id and name attributes of your form fields before appending your new row to the table. You would also need a hidden form field to keep track of the number of hidden rows. When your user finaly hits the "save" button, on the C# side, get the number of additional rows from you hidden field the go old school and use Request.Form[] to get the value of each of your added fields.
This, in my opionion, will be a smoother experience for the end user.
Another, somewhat hacky option,if you have a defined maximum number of additional rows. For this have the mamimum rows, with form controls in the table. You can then either use visible="false" in the aspx and use post back to change that to visible="true" when the user clicks "add". The other option there is to give the row a CSS class that hides the row and then use javascript/jquery to remove the class to make the row visible.

The issue here is that you are not understanding the ASP.Net Page Lifecycle and more importantly how it interacts with dynamic controls (your added controls.)
Unfortunately, we can not answer this question without understanding whether the values in these "dynamically" created controls are used server-side or client-side.
I can guess that:
1) If they are for client side consumption/usage, you are doing wrong. If you need more info ask another (more specific) question.
2) If they are for server side consumption/usage, you must only allow one new record per postback, and should include a "Save" button that will save the current "new" row and cause a page refresh that the user can add a new entry to.
3) See rule #0 (Every rule has exceptions. {This rule applies in so far that you understand the problem at hand.})
Monk

Gridview Row Events not firing in UserControl

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.

GridView RowUpdating does not get the new values

I have at the moment a problem with RowUpdating from a GridView and accessing the new values. I add a dynamic DataTable to my GridView.DataSource and bind to it. If I use the update button nothing happens and I get back to my normal GridView.
Here's my Page_Load event:
protected void Page_Load(object sender, EventArgs e)
{
Control test = GetPostBackControl(Page);
if (Page.IsPostBack)
{
if ((test.ID == "SumbitSearch") && (DropDownListFrom.Text != "") && (DropDownListTo.Text != "") && (SearchField.Text != ""))
{
DataTable result = new DataTable();
string from = null;
string to = null;
switch (DropDownListFrom.SelectedIndex)
{
case 0:
from = DropDownListFrom.Items[0].Value;
break;
case 1:
from = DropDownListFrom.Items[1].Value;
break;
case 2:
from = DropDownListFrom.Items[2].Value;
break;
}
switch (DropDownListTo.SelectedIndex)
{
case 0:
to = DropDownListTo.Items[0].Value;
break;
case 1:
to = DropDownListTo.Items[1].Value;
break;
case 2:
to = DropDownListTo.Items[2].Value;
break;
}
result = LoadGridView(from, to);
GridViewResult.DataSource = result;
Session["Result"] = result;
GridViewResult.DataBind();
GridViewResult.Columns[0].Visible = true;
GridViewResult.Columns[1].Visible = true;
GridViewResult.HeaderRow.Cells[0].Width = Unit.Pixel(110);
GridViewResult.HeaderRow.Cells[1].Width = Unit.Pixel(60);
GridViewResult.HeaderRow.Cells[3].Text = "Nach: " + from;
GridViewResult.HeaderRow.Cells[4].Text = "Von: " + to;
}
}
else
{
GridViewResult.DataBind();
}
}
Later, the GridView should only appear if both DropDownLists are used and the SearchField is not empty. I also check if the button which execute the PostBack is the search button.
Here is what I added to the RowUpdating EventHandler:
protected void TaskGridViewResult_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
GridViewResult.DataSource = (DataTable)Session["Result"];
for (int i = 0; i < GridViewResult.Columns.Count; i++)
{
DataControlFieldCell cell = GridViewResult.Rows[e.RowIndex].Cells[i] as DataControlFieldCell;
GridViewResult.Columns[i].ExtractValuesFromCell(e.NewValues, cell, DataControlRowState.Edit, true);
}
GridViewResult.EditIndex = -1;
DataBind();
}
What is going wrong?
Last Change: More Information (#jwiscarson)
I’m sorry, I was in hurry. I will try to give you a better view.
In that project, the users could select 2 categories, enter a search string and the result will show in a GridView. The RowUpdating stuff is for the "admin user".
Here is my problem, if the "admin user" click on edit, change the value of the cell and execute the update, the value would not changed in the DataTable.
Without seeing your markup, it's hard for […] based on some search
criteria?
I add GridViewResult as markup in my project.
I'm also not sure why […] within that button's Click event.
Yes, I thought that too! But I read in a blog it is better to put the code into Page_Load(), if you are working with GridViews. I believed him. Is it okay, to put that code into the click event handler from my button? I'm very new to that. I just could read lots of blogs, msdn and ask here.
TaskGridViewResult_RowUpdating is also added as markup to my code. Could I also create this and the GridView in my CreateChildControls()?
As markups I have two DropDownLists, a TextBox for the search string, a search submit Button and the GridView.
At the moment, i havent the exactly code here but the GridView looks like:
<asp:GridView ID="GridView1" runat="server"
OnRowUpdating="TaskGridViewResult_RowUpdating">
<!-- // More of that... -->
<Columns>
<asp:CommandField ShowEditButton="True" />
<asp:CommandField ShowDeleteButton="True" />
</Columns>
</asp:GridView>
I could give you more details tomorrow.
Maybe I forgot this. Before I could click the update button and execute the TaskGridViewResult_RowUpdating event to change the value of the cell. I set the row editable with:
protected void TaskGridViewResult _RowEditing(object sender, GridViewEditEventArgs e)
{
GridViewResult.EditIndex = e.NewEditIndex;
DataBind();
}
Next Change:
I added to the GridView few TemplateFields like:
<asp:TemplateField HeaderText="test">
<EditItemTemplate>
<asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("from") %>'> </asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label2" runat="server" Text='<%# Bind("from") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
This is it, I have access to the new value with:
string test = ((TextBox)row.FindControl("TextBox1")).Text;
in TaskGridViewResult_RowUpdating()
Now, I just have to bind the template dynamically with the values from the dropdown list, and that’s it I think.
Thanks!

Hoo boy.
You didn't ask this in your question, but you've written some smelly code here. I'll try to address your question, but I'm also going through some of the other problems here.
Without seeing your markup, it's hard for me to tell if you've created GridViewResult programmatically or if it's in your markup as well. I'm not exactly sure what TaskGridViewResult is either -- is this an event for GridViewResult? Do you have another GridView on your page, and you want to show GridViewResult based on some search criteria?
I'm also not sure why you put all of your GridView binding code in Page_Load. I see that you're checking GetPostBackControl to find the control that caused the PostBack -- this is a code smell. If your users have to click a specific "Search" button, you should isolate your GridView binding code within that button's Click event.
Anyway, as to TaskGridViewResult_RowUpdating:
It looks like you're trying to update GridViewResult's old values to the new values by setting its DataSource and then iterating through its data. You can't do that. What happens when you change your RowUpdating event to:
protected void TaskGridViewResult_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
GridViewResult.DataSource = (DataTable)Session["Result"];
GridViewResult.DataBind();
}
Now, other asides:
Your switch statements are code smells. DropDownLists expose a property called SelectedValue -- if you have some default value that isn't a valid selection (like the first option in your DropDownList), then you can change your original code from:
if ((test.ID == "SumbitSearch") && (DropDownListFrom.Text != "") && (DropDownListTo.Text != "") && (SearchField.Text != ""))
{
string from = string.Empty;
string to = string.Empty;
switch (DropDownListFrom.SelectedIndex)
{
case 0:
from = DropDownListFrom.Items[0].Value;
break;
/* other cases */
}
switch (DropDownListTo.SelectedIndex)
{
case 0:
to = DropDownListTo.Items[0].Value;
break;
/* other cases */
}
/* snip */
}
to:
if (test.ID == "SubmitSearch" && DropDownListFrom.SelectedIndex > 0 && DropDownListTo.SelectedIndex > 0 && SearchField.Text != "")
{
string from = DropDownListFrom.SelectedValue;
string to = DropDownListTo.SelectedValue;
/* snip */
}
If you can, please post your markup. I can offer you some more specific help or advice if I can tell what Controls you have on your page, and how they interact.
Edit: I should also add that you should get in the habit of using String.IsNullOrEmpty(string variable), rather than comparing to "". Although this isn't as big of a problem when you're referencing the text from web controls, getting in the habit now will prevent you from serious headaches and inefficiently checking for null and empty later. If you're in .NET 4.0, you should have access to IsNullOrWhiteSpace(), which is (in my opinion) more useful on the web, where users are more likely to try to enter junk data.
Edit 2: In response to your additional details above:
In your RowUpdating event, you need to pull the new values out of the front-end controls, and then re-bind your data. It looks like your source code is pretty close to the MSDN source code here. The difference between your code and the code on MSDN is:
- The MSDN code takes the new data from the edited row and updates the appropriate data in the Session variable with that new data.
- The MSDN code has a BindData() function -- I'm not sure if this is what your DataBind() function is, however.
- The MSDN code updates the GridView by re-binding the GridView to the appropriate data in the Session.
Frankly, I have some issues with the MSDN code. I really, really hate seeing code like: dt.Rows[row.DataItemIndex]["Id"] = ((TextBox)(row.Cells[1].Controls[0])).Text; To me, this is garbage, because it's so highly coupled to the order of your cells.
If I had written the code, I would explicitly create all the front-end controls and use a binding command (if you aren't familiar, it looks like <%# DataBinder.GetPropertyValue(Container.DataItem, "FieldName") %> in the markup -- see more details here). Then, in my RowUpdating event, I'd use e.Row.FindControl("controlName"), and update the Session data from that.
Honestly, if your back-end data isn't changing on a regular basis, I don't see any reason to programmatically create your GridViews. It over-complicates your C# code to go through these steps yourself when you can just set it up once in your markup. If you need to hide one GridView, you can always set its Visible property to false. Then, when you're ready to show it, set Visible = true.
Finally, I've spread my GridView code across so many events (button clicks, RowDataBound events from other GridViews/Repeaters, etc.), I can't imagine why someone would suggest that you only put it in Page_Load.