Develop Reference

ItemDataBound in A Datalist in ASP.NET

After reading Formatting the DataList and Repeater Based Upon Data (C#) on Microsoft Website I found the following code sample.
protected void ItemDataBoundFormattingExample_ItemDataBound(object sender, DataListItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item ||
e.Item.ItemType == ListItemType.AlternatingItem)
{
// Programmatically reference the ProductsRow instance bound
// to this DataListItem
Northwind.ProductsRow product =
(Northwind.ProductsRow)((System.Data.DataRowView)e.Item.DataItem).Row;
// See if the UnitPrice is not NULL and less than $20.00
if (!product.IsUnitPriceNull() && product.UnitPrice < 20)
{
// TODO: Highlight the product's name and price
}
}
}
However in the above I would like to know where Northwind.ProductsRow product is coming from. Is it from the Northwind database name or somewhere else.

this is a great question, and like some time travel movie, I REALLY WISH someone had and did explain how this works. You note that sometimes the "data source" of the datalist works, and sometimes it does not, and why is this so???
So, the data source comes from WHEN the control was "binded" or spoon fed the data source.
So, on page load, there is most likly some code that set-up and "binds" the data control. Or, it might be that a sqldatasource was dropped into the web page, but AGAIN, either way?
The page load will then trigger the row data bound event.
(ItemDataBound).
So, first BIG tip:
The e.Item.DataItem used IS ONLY available DURING the data bind process. That quite much means at data bind time and the ItemDataBound event.
So, WHEN you shove a data source INTO the GridView, Datalist, ListView, repeater etc controls? And use the data bound event (the name varies a wee bit, bu they all do the same thing), then the DataItemView is ONLY available DURING the row data bind process and hence you are 100% free to use that data source DURING the data bind event - BUT NOT AFTER!!!!!
After, binding has occured, you find that the the dataitem (and control datasoruce is NOW null!!!!). This is VERY different then desktop versions of such controls in .net (in desktop land, you actually can get/use/see the ACTUAL object used for each row!!! - and they persist!!!!
In web land, that data source is converted to a DataRowView.
However, what is the basic knowledge here?
Well, it means that your data control does NOT have to display or hide all of the columns from the database, but you ARE STILL FREE to use those additional columns for things like tax calculations, or for formatting controls based on OTHER columns that you have in the datasource BUT ARE NOT DISPLAYED!!!
And you see BOATLOADS of examples posted where people use hidden fields and all kinds of tricks, and they did that because they DID NOT KNOW the above!!!
Now, it not clear if you want to use a "datalist" control. They tend to be good for say one reocrd, or say several records in a "card like" view - not a table like layout.
So, for a table like layout, I suggest using ListView (most flexible), or for simple, and not too fancy, then use GridView.
But, DataList, listView, GridView, Repeater ? They all of this Row bound (or Item bound) event (they all are VERY close named).
And as noted, JUST like your question, in most cases this event can be used for addtional formatting.
Lets do this with a GridView - (since it easy).
So, say we have a grid of hotel names, but I want to highlight in say blue color ONLY hotels that are active. But I ALSO do NOT want to display the "active" column from the data base in that grid.
So, say this simple markup:
<style> .MyCenter {text-align:center;}</style>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
DataKeyNames="ID" cssclass="table" OnRowDataBound="GridView1_RowDataBound">
<Columns>
<asp:BoundField DataField="FirstName" HeaderText="FirstName" />
<asp:BoundField DataField="LastName" HeaderText="LastName" />
<asp:BoundField DataField="City" HeaderText="City" />
<asp:BoundField DataField="HotelName" HeaderText="HotelName" ItemStyle-Width="120px" />
<asp:BoundField DataField="Description" HeaderText="Description" />
<asp:TemplateField HeaderText="View" >
<HeaderStyle CssClass="MyCenter"/>
<ItemStyle CssClass="MyCenter" />
<ItemTemplate>
<asp:Button ID="bView" runat="server" Text="View" CssClass="btn" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
Now, our code to load, we have this:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
LoadGrid();
}
void LoadGrid()
{
using (SqlConnection conn = new SqlConnection(Properties.Settings.Default.TEST4))
{
string strSQL = "SELECT * FROM tblHotelsA ORDER BY HotelName";
using (SqlCommand cmdSQL = new SqlCommand(strSQL,conn))
{
conn.Open();
DataTable rstData = new DataTable();
rstData.Load(cmdSQL.ExecuteReader());
GridView1.DataSource = rstData;
GridView1.DataBind();
}
}
}
And we now have this:
So, lets use the ItemDataBound event (RowdataBound for Gridview) to highlight the Hotel name and descrption ONLY for Hotels that are active. As noted, we do NOT display "Active" column in the gridview, but with Row data bound event, we still have use of the FULL row.
So, we can add this code to the Row data bound event.
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
// get the full data row used for binding
DataRowView OneRow = e.Row.DataItem as DataRowView;
// lets highlist the hotel name + description
if ((bool)OneRow["Active"])
{
e.Row.Cells[3].BackColor = System.Drawing.Color.LightSteelBlue;
e.Row.Cells[4].BackColor = System.Drawing.Color.LightSteelBlue;
}
// that button is not centered "vertical", so lets do that
Button btn = e.Row.FindControl("bView") as Button;
DataControlFieldCell g = btn.Parent as DataControlFieldCell;
g.Style.Add("vertical-align", "middle");
}
}
And now we we get this:
So, what about the view item click? For that we could use a datalist as you have, and we could then hide the grid, display the datalist, and we would be quite much on our way with a grid to edit items, then right?
Coffee break - I'll be back in a bit to add the view + datalist to see/view/edit one item.
Ok, part 2 - using a datalist to display above click
Ok, so lets drop in a data list - with a div area (to hide and show).
So, ok, now our data list we drop in.
<div id="MyEditArea" runat="server" style="width:44%;margin-left:35px;padding:8px;border:solid;display:none">
<asp:Datalist ID="DataList1" runat="server" DataKeyField="ID" >
<ItemTemplate>
<style>
.iForm label {display:inline-block;width:95px}
.iForm input {border-radius:8px;border-width:1px;margin-bottom:10px}
.iForm textarea {border-radius:8px;border-width:1px;margin-bottom:10px}
.iForm input[type=checkbox] {margin-right:6px}
</style>
<div style="float:left" class="iForm">
<label>HotelName</label>
<asp:TextBox ID="txtHotel" runat="server" Text='<%# Eval("HotelName") %>' width="280" /> <br />
<label>First Name</label>
<asp:TextBox ID="tFN" runat="server" Text='<%# Eval("FirstName") %>' Width="140" /> <br />
<label>Last Name</label>
<asp:TextBox ID="tLN" runat="server" Text='<%# Eval("LastName") %>' Width="140" /> <br />
<label>City</label>
<asp:TextBox ID="tCity" runat="server" Text='<%# Eval("City") %>' Width="140" /> <br />
<label>Province</label><asp:TextBox ID="tProvince" runat="server" Text='<%# Eval("Province") %>'
f="Province" Width="75"></asp:TextBox> <br />
</div>
<div style="float:left;margin-left:20px;width:420px " class="iForm">
<label>Description</label> <br />
<asp:TextBox ID="txtNotes" runat="server" Width="400" TextMode="MultiLine"
Height="150px" Text='<%# Eval("Description") %>' ></asp:TextBox> <br />
<asp:CheckBox ID="chkActive" Checked='<%# Eval("Active") %>' Text=" Active" runat="server" TextAlign="Right" />
<asp:CheckBox ID="chkBalcony" Checked='<%# Eval("Balcony") %>' Text=" Has Balcony" runat="server" TextAlign="Right" />
<asp:CheckBox ID="chkSmoking" Checked='<%# Eval("Smoking") %>' Text=" Smoking Area" runat="server" TextAlign="Right" />
</div>
<div style="clear:both"></div>
<div style="float:left" class="iForm">
<asp:Button ID="cmdSave" runat="server" Text="Save" CssClass="btn" />
<asp:Button ID="cmdCancel" runat="server" Text="Cancel" CssClass="btn" style="margin-left:10px" />
</ItemTemplate>
</asp:Datalist>
And now our button click for the grid view - to display that one data list control + data.
Hum, started writing some code routine, so lets clean this up a bit.
Ok, so we now have this to load + format the gridview.
void LoadGrid()
{
GridView1.DataSource = MyRst("SELECT * FROM tblHotelsA ORDER BY HotelName");
GridView1.DataBind();
}
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
// get the full data row used for binding
DataRowView OneRow = e.Row.DataItem as DataRowView;
// lets highlist the hotel name + description
if ((bool)OneRow["Active"])
{
e.Row.Cells[3].BackColor = System.Drawing.Color.LightSteelBlue;
e.Row.Cells[4].BackColor = System.Drawing.Color.LightSteelBlue;
}
// button is not centered "vertical", so lets do that
Button btn = e.Row.FindControl("bView") as Button;
DataControlFieldCell g = btn.Parent as DataControlFieldCell;
g.Style.Add("vertical-align", "middle");
}
}
void CenterControl(Control c)
{
DataControlFieldCell g = c.Parent as DataControlFieldCell;
g.Style.Add("vertical-align", "middle");
}
public DataTable MyRst(string strSQL)
{
DataTable rstData = new DataTable();
using (SqlConnection conn = new SqlConnection(Properties.Settings.Default.TEST4))
{
using (SqlCommand cmdSQL = new SqlCommand(strSQL, conn))
{
conn.Open();
rstData.Load(cmdSQL.ExecuteReader());
}
}
return rstData;
}
And for the button click on the grid, we have this now:
protected void bView_Click(object sender, EventArgs e)
{
Button btn = sender as Button;
GridViewRow gRow = btn.NamingContainer as GridViewRow;
int? PKID = GridView1.DataKeys[gRow.RowIndex]["ID"] as int?;
// Now load our datalist
string strSQL = "SELECT * from tblHotelsA WHERE ID = " + PKID;
DataList1.DataSource = MyRst(strSQL);
DataList1.DataBind();
// hide grid, show edit area
GridView1.Style.Add("display", "none");
MyEditArea.Style.Add("display", "normal");
}
So, now when we click on a row, we hide grid, show our data list control, and we now see/have this:
And just like the grid view, lets highlight the hotelname and description as light grey. Once again, we now use the data list row data bound event.
Say, this:
Note how we don't use .cells for the data list, but have to use find control.
protected void DataList1_ItemDataBound(object sender, DataListItemEventArgs e)
{
if ( (e.Item.ItemType == ListItemType.Item) |
e.Item.ItemType == ListItemType.AlternatingItem)
{
DataRowView gData = e.Item.DataItem as DataRowView;
if ((bool)gData["Active"])
{
TextBox txtHotel = e.Item.FindControl("txtHotel") as TextBox;
txtHotel.BackColor = System.Drawing.Color.LightSteelBlue;
TextBox txtDescript = e.Item.FindControl("txtNotes") as TextBox;
txtDescript.BackColor = System.Drawing.Color.LightSteelBlue;
}
}
}
And, you do have to check for item, and "alternating" item.
But, now, when we click on a grid row, we get this:

How to add Delete link in GridView while adding new row from C#?

GridView contains ShowDeleteButton CommandField along with other textbox fields.
I'm adding new row to this grid in C# that is adding new textboxes for each newly added row. How to add Delete link while adding new row?
<asp:GridView ID="Gridview1" runat="server" ShowFooter="true" OnRowDataBound="Gridview1_OnRowDataBound"
OnRowDeleting="Gridview1_RowDeleting" AutoGenerateColumns="false" ShowHeaderWhenEmpty="True" EmptyDataText="No Record Available">
<asp:TemplateField HeaderText="Question">
<asp:TextBox ID="txtQuestion" runat="server" Text='<%# Eval("Question") %>'></asp:TextBox>
</asp:TemplateField>
<asp:TemplateField HeaderText="Answer">
<ItemTemplate>
<asp:TextBox ID="txtAnswer" ReadOnly="true" Enabled="false" runat="server" Text='<%# Eval("Answer") %>'></asp:TextBox>
</ItemTemplate>
<FooterStyle HorizontalAlign="Right" />
<FooterTemplate>
<asp:Button ID="btnAddNewQuestionnaire" runat="server" Text="Add New Row" OnClick="btnAddNewQuestionnaire_Click" />
</FooterTemplate>
</asp:TemplateField>
<asp:CommandField ShowDeleteButton="true" />
</Columns>
</asp:GridView>
private void AddNewRow()
{
DataTable dt = new DataTable();
DataRow dr;
dt.Columns.Add(new System.Data.DataColumn("Question", typeof(String)));
dt.Columns.Add(new System.Data.DataColumn("Answer", typeof(String)));
foreach (GridViewRow row in Gridview1.Rows)
{
TextBox txtQuestion = (TextBox)row.FindControl("txtQuestion");
TextBox txtAnswer = (TextBox)row.FindControl("txtAnswer");
dr = dt.NewRow();
dr[0] = txtQuestion.Text;
dr[1] = txtAnswer.Text;
dt.Rows.Add(dr);
}
dt.Rows.Add(dt.NewRow());
dt.Rows[dt.Rows.Count - 1]["Question"] = "";
dt.Rows[dt.Rows.Count - 1]["Answer"] = "";
dt.AcceptChanges();
Gridview1.EditIndex = dt.Rows.Count - 1;
Gridview1.DataSource = dt;
Gridview1.DataBind();
}

I recommend that you simple add the delete button to each row. That way the user can easy delete a row.
I also recommend that you load the grid one time with the datatable, and then add the row to the datatable - NOT the grid.
I could write tuckloads of advantages of this approach. But some advantages are:
user does not get presented with multiple UI
user can edit any row on the grid - not have to hit edit, or save
a single un-do button can un-do all changes
a single SAVE button in ONE operation can save the WHOLE TABLE and change back to database
Your code to add a row, and the code to setup and create the database are seperate. This means that you can change the data table, or even have the source of the table come from sql server. And as noted, this also allows you to save the WHOLE table. The result is the user can edit one rows, many rows - tab around MUCH like a excel spreadsheet. When done, they can:
hit save - all data back to database
hit un-do - un-do all their edits
hit + (add row) - add a new row to edit
hit delete key - it will delete the row in question (but UN-DO STILL ACTIVE!!!).
so we have a far more pleasant way to edit.
And thus, I suggest you don't use the built in delete button. Drop in your own button - it will look nicer anyway. (and thus no edit button required either!!!!).
So, here is our markup:
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<asp:ImageButton ID="ImageButton1" runat="server"
ImageUrl="~/Content/uncheck1.jpg" Height="35px" Width="45px"
OnClick="ImageButton1_Click"
MyRowID = '<%# Container.DataItemIndex %>' />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Question">
<ItemTemplate>
<asp:TextBox ID="txtQuestion" runat="server" Text='<%# Eval("Question") %>'></asp:TextBox>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Answer">
<ItemTemplate>
<asp:TextBox ID="txtAnswer" runat="server" Text='<%# Eval("Answer") %>'></asp:TextBox>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
<br />
<asp:Button ID="btnAddNewQuestionnaire" runat="server" Text="+Add New Row" OnClick="btnAddNewQuestionnaire_Click" />
When you drop the button (I used a image button), then in the code editor do this:
Note how RIGHT after you hit "=" then intel-sense pops up - choose create new event. It looks like NOTHING occurs, but if you flip over to code behind, you see a code sub was generated. You can't double click on the controls inside the grid, but you CAN create a event click for a button - or in fact any event for a standard asp.net control this way.
I also to save world poverties also added a custom attribute to that button called MyRowID - this will set the row index for that button.
Since the add new row button is OUTSIDE of the grid, then we can just double click on that button, and jump to the code behind.
Now, our code looks like this:
private DataTable MyTable = new DataTable();
protected void Page_Load(object sender, System.EventArgs e)
{
if (IsPostBack == false)
{
LoadGrid();
ViewState["MyTable"] = MyTable;
}
else
MyTable = ViewState["MyTable"];
}
public void LoadGrid()
{
MyTable.Columns.Add(new DataColumn("Question", typeof(string)));
MyTable.Columns.Add(new DataColumn("Answer", typeof(string)));
GridView1.DataSource = MyTable;
GridView1.DataBind();
}
protected void btnAddNewQuestionnaire_Click(object sender, EventArgs e)
{
DataRow MyRow = MyTable.NewRow;
MyRow("Question") = "my question";
MyRow("Answer") = "my ans";
MyTable.Rows.Add(MyRow);
GridView1.DataSource = MyTable;
GridView1.DataBind();
}
protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
{
ImageButton btn = sender;
int RowID = btn.Attributes.Item("MyRowID");
MyTable.Rows(RowID).Delete();
GridView1.DataSource = MyTable;
GridView1.DataBind();
}
Note VERY carefull - we added a MyTable to the form class. Thus we have a persited table, and we operate against that table.
In fact, the EXACT same above desing can be used if the data came from SQL server. And not only MORE amazing, but we can NOW thus SAVE + SEND the whole table BACK to sql server in one update operation. (you just loop the grid, put values back into table, and execute one save).
And the above has no messy edit button to edit a row. and I suppose we COULD add for extra marks a delete conformation box - the user if they bump or hit delete button, they would get a confirm dialog box. That code could be this:
<asp:ImageButton ID="ImageButton1" runat="server"
ImageUrl="~/Content/uncheck1.jpg" Height="35px" Width="45px"
OnClick="ImageButton1_Click"
MyRowID = '<%# Container.DataItemIndex %>'
OnClientClick="return confirm('Delete this row?');"/>
So now when you hit delete row, you get this:
If you click ok - it deletes - cancel - nothing occurs.
So, you can save a LOT of code and complexity here with:
Persist the data table
Pass the row ID with the button
use the intel-sense trick to wire up a separate and specific button event code.
As noted, this whole above process would ALSO work if you load the table with data from sql server - the REST of the code "as is" will work.
And to save the data back to sql server, then you can as noted:
Pull data from grid back to that persisted table. And then with a data adaptor, ONE update command will send all changes back to sql server.

c# Cannot Convert from string to int

I have a gridview that populates from an SQL table and shows two columns, one comes from an integer data column, the other from an nvarchar. Gridview also has a checkbox column
The gridview populates correctly, and after a subset of rows is selected (via checkbox column) I want to insert the selected rows into another SQL table. When populating the variables for the SQL statement however I get the "Cannot Convert from string to int" error on the value that is populated from an int to begin with.
I have tried writing up convert and parse for this statement but still getting the error:
cmd.Parameters.AddWithValue("#PracticeArea", int.Parse(row.Cells["Id"].Value));
cmd.Parameters.AddWithValue("#PracticeArea", Convert.ToInt32(row.Cells["Id"].Value));
cmd.Parameters.AddWithValue("#PracticeArea", Convert.ToInt32(row.Cells["Id"].Text));
All still show the error on the ["Id"] value.
Any thoughts?
Example of the data that is being populated to the gridview is:
PracticeID PracticeName
1 General Surgical Pathology
2 General Pathology/Basic Science
4 Cardiovascular
6 Cytopathology-GYN
7 Cytopathology-nonGYN
Full button command is:
protected void Bulk_Insert(object sender, EventArgs e)
{
foreach (GridViewRow row in GridView1.Rows)
{
if ((row.FindControl("CheckBox1") as CheckBox).Checked)
{
string connectionString = WebConfigurationManager.ConnectionStrings["CS1"].ConnectionString;
SqlConnection con = new SqlConnection(connectionString);
{
using (SqlCommand cmd = new SqlCommand("INSERT INTO ReviewerPractice VALUES(#Reviewer, #PracticeArea)", con))
{
cmd.Parameters.AddWithValue("#Reviewer", ReviewerName.Text);
cmd.Parameters.AddWithValue("#PracticeArea", Convert.ToInt32(row.Cells["Id"].Value));
con.Open();
cmd.ExecuteNonQuery();
con.Close();
}
}
}
}
}
Full Gridview control is:
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<asp:CheckBox ID="CheckBox1" runat="server" />
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="Id" HeaderText="Id" ItemStyle-Width="30" />
<asp:BoundField DataField="PracticeName" HeaderText="PracticeName" ItemStyle-Width="150" />
</Columns>
</asp:GridView>
<br />
<asp:Button ID="Button1" Text="Add Practice Areas" OnClick="Bulk_Insert" runat="server" />
Hope this answers (some?) of the questions from all the comments to date.

The problem is that row.Cells[] is an array, so you need to use it like this:
row.Cells[3].Text
And it's better to use the Parameters for sql like this:
cmd.Parameters.Add("#PracticeArea", SqlDbType.Int).Value = Convert.ToInt32(row.Cells[index].Text;

ASP.NET GridView Column Remove

I have a GridView with some predefined Columns and some generated in code. The idea is that I show Columns according to category, selected by user. I cannot create all Columns and just hide them because I don't know how many Columns I will need. I manage to generate Columns I needed, but the problem starts when I try to remove generated Columns. Situation looks like this:
On first load I see GridView of all categories.
After clicking in ListBox I get result I want. 1 additional Column is created (RemoveAt is not called, because no additional Columns were yet created.).
After clicking in other ListBox Item I still get result I want. Column created last time where deleted and new Column added.
At this point, if I click any other ListBox Item in LicensesCategoriesListBox_SelectedIndexChanged on debugging I see that all of GridView TemplateFields are empty (http://tinypic.com/r/98vdkm/8).
If I comment section gridView.Columns.RemoveAt(i - 1) everything works fine, just Columns keeps generating and generating. Any ideas why all of my TemplateFields, written in my Page becomes empty?
My Page looks like this:
<asp:ListBox ID="licensesCategoriesListBox" runat="server" AutoPostBack="true" OnSelectedIndexChanged="LicensesCategoriesListBox_SelectedIndexChanged" />
<asp:GridView ID="licencesGridView" runat="server" AutoGenerateColumns="False" Caption="Licencijos" DataKeyNames="id" ShowFooter="True">
<Columns>
<asp:TemplateField HeaderText="Pavadinimas">
<EditItemTemplate>
<asp:TextBox ID="licenceNameTextBox" runat="server" MaxLength="50" Text='<%# Bind("name") %>' />
</EditItemTemplate>
<FooterTemplate>
<asp:TextBox ID="newLicenceNameTextBox" runat="server" MaxLength="50" ToolTip="Pavadinimas" />
</FooterTemplate>
<ItemTemplate>
<span><%# Eval("name") %></span>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Kategorija">
<EditItemTemplate>
<asp:DropDownList ID="licenceCategoryDropDownList" runat="server" />
</EditItemTemplate>
<FooterTemplate>
<asp:DropDownList ID="newLicenceCategoryDropDownList" runat="server" ToolTip="Kategorija">
<asp:ListItem Text="Pasirinkite kategoriją:" />
</asp:DropDownList>
</FooterTemplate>
<ItemTemplate>
<span><%# Eval("category") %></span>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
Code:
protected void Page_Load(object sender, EventArgs e) {
if (!IsPostBack) {
FillLicences(ref licencesGridView);
}
}
protected void LicensesCategoriesListBox_SelectedIndexChanged(object sender, EventArgs e) {
FillLicences(ref licencesGridView, licensesCategoriesListBox.SelectedValue); /// Value is ID of category.
}
public void FillLicences(ref GridView gridView, string category = "") {
DataTable dataTable;
ushort categoryId;
if (UInt16.TryParse(category, out categoryId)) {
PutAdditionalColumns(ref gridView, categoryId);
dataTable = sqlCommands.GetLicences(categoryId); /// Returns DataTable [name], [category] and additional fields that I add in PutAdditionalColumns method.
} else {
dataTable = sqlCommands.GetAllLicences(); /// Returns DataTable with only [name], [category]
}
gridView.DataSource = dataTable;
gridView.DataBind();
}
public void PutAdditionalColumns(ref GridView gridView, uint category) {
for (ushort i = (ushort)gridView.Columns.Count; i > 2; i--) { /// Removes columns at the end (created for other category)
gridView.Columns.RemoveAt(i - 1);
}
foreach (var pair in sqlCommands.GetLicencesCategoryAttributes(category)) { /// Takes additional field needed.
TemplateField field = new TemplateField(); /// New empty column.
field.AccessibleHeaderText = pair.Key.ToString();
field.HeaderText = pair.Value;
gridView.Columns.Add(field);
}
}

Any ideas why all of my TemplateFields, written in my Page becomes
empty?
Because each of those fields is considered a Column. You're removing them in the code.
If this is your issue, you need some way to seperate columns defined in the aspx to the ones created in the code.
I'd use DataColumn.ExtendedProperties to do this.
Whenever you add a column from code, add a value to ExtendedProperties, showing that it was created in the code.
//...
TemplateField field = new TemplateField(); /// New empty column.
field.AccessibleHeaderText = pair.Key.ToString();
field.HeaderText = pair.Value;
DataColumn ourNewColumn = gridView.Columns.Add(field);
ourNewColumn.ExtendedProperties.Add("CreatedInCode", true);
//...
And then when you come to delete them, only delete them if they have this property set.
//...
if( gridView.Columns[i - 1].ExtendedProperties.ContainsKey("CreatedInCode") ) {
gridView.Columns.RemoveAt(i - 1);
}
//...

gridview column value manipulated

my intention was to switch form an int-represented month value
(as it is in database table)
convert it (to display in GridView) as string(month name)
and return it back to database as int (covert back to original type, int-represented month).
these are the relevant elements in my GridView,
<asp:GridView ID="GV_DaysPerMonth" runat="server" DataSourceID="dsWorkDayPerMonth"
AutoGenerateColumns="False" DataKeyNames="recordID" AllowPaging="True"
CellPadding="4" ForeColor="#333333" GridLines="None" Font-Names="arial" PageSize="12"
OnRowDataBound="GV_DaysPerMonth_RowDataBound"
OnRowEditing="GV_DaysPerMonth_RowEditing"
OnRowUpdating="GV_DaysPerMonth_RowUpdating">
<AlternatingRowStyle BackColor="White" />
<Columns>
<asp:TemplateField HeaderText="חודש" ControlStyle-Width="100" HeaderStyle-Width="120" ItemStyle-HorizontalAlign="Center">
<ItemTemplate>
<%# Eval("theMonth")%>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="TBX_theMonth" runat="server" Text='<%# Bind("theMonth")%>' />
</EditItemTemplate>
<asp:GridView ID="GV_DaysPerMonth" runat="server" DataSourceID="dsWorkDayPerMonth"
AutoGenerateColumns="False" DataKeyNames="recordID" AllowPaging="True"
CellPadding="4" ForeColor="#333333" GridLines="None" Font-Names="arial" PageSize="12"
OnRowDataBound="GV_DaysPerMonth_RowDataBound"
OnRowEditing="GV_DaysPerMonth_RowEditing"
OnRowUpdating="GV_DaysPerMonth_RowUpdating">
<AlternatingRowStyle BackColor="White" />
<Columns>
<asp:TemplateField HeaderText="Current Month" ControlStyle-Width="100" HeaderStyle-Width="120" ItemStyle-HorizontalAlign="Center">
<ItemTemplate>
<%# Eval("theMonth")%>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="TBX_theMonth" runat="server" Text='<%# Bind("theMonth")%>' />
</EditItemTemplate>
i was tring using these Helper methods From code Behind
public static CultureInfo ILci = CultureInfo.CreateSpecificCulture("he-IL");
public static string GetMonthName(int mInt)
{
DateTime fullDate = new DateTime(2012, mInt, 2);
string[] tempDayArray = fullDate.ToString("MMMM", ILci).Split(' ');
return tempDayArray[0];
}
public static int GetMonthAsInt(string mStr)
{
return DateTime.ParseExact(mStr, "MMMM", ILci).Month;
to achieve this simple task but had few errors i would like to have an example to how is the right way to achieve it.
i thought it's simple cause displaying int via
<%# manipulation Function( Eval("columnName")) %>
would "just work"
but it got too complicated for me as newb
when trying it with Bind("columnName")
i was wrong by assuming the value was inside Cells[1] when it was actually in Cells[0]
so i do have it in normal mode
and also in Edit mode though not editble but via Label as in view mode instead of a TextBox
protected void GV_DaysPerMonth_RowDataBound(object sender, GridViewRowEventArgs e)
{
RowNum = GV_DaysPerMonth.Rows.Count;
GridViewRow CurRow = e.Row; // Retrieve the current row.
if (CurRow.RowType == DataControlRowType.DataRow)
{
bool isntEmptyMonth = string.IsNullOrEmpty(e.Row.Cells[0].Text) == false;
if (isntEmptyMonth)
{
e.Row.Cells[1].Text = RobCS.RDates.GetMonthName(Convert.ToInt32((e.Row.Cells[0].Text)));
}
}
}
so i think it might be the **missing handler for the edit mode** ?

This is what you would do to get a string Month name from an int:
CultureInfo.CurrentCulture.DateTimeFormat.GetMonthName(1);
More info here:
Best way to turn an integer into a month name in c#?
For converting month number into month name in sql server, look here:
Convert Month Number to Month Name Function in SQL
---- EDIT
OK, on RowDataBound, you would want to convert int to string, so it would be something like:
void CustomersGridView_RowDataBound(Object sender, GridViewRowEventArgs e)
{
if(e.Row.RowType == DataControlRowType.DataRow)
{
// Display the month name. When you GridView is bound for the first time, you
// will bind the month number, which you can get in e.Row.Cells[1].Text. If
// Cells[1] does not work, try Cells[2], till you get the correct value. The
// convert the int to month name and assign it to the same Cell.
e.Row.Cells[1].Text = GetMonthNameFromInt(e.Row.Cells[1].Text)
}
}
On Row_updating, you want to convert the month name to int again, and then update you dataset (or save to the database)
protected void GridView_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
//Update the values.
GridViewRow row = GridView.Rows[e.RowIndex];
var monthName = ((TextBox)(row.Cells[1].Controls[0])).Text;
var monthNumber = GetMonthNumber(monthName);
// code to update your dataset or database with month number
//Reset the edit index.
GridView.EditIndex = -1;
//Bind data to the GridView control.
BindData();
}

Page class:
private static CultureInfo culture = CultureInfo.CreateSpecificCulture("he-IL");
public static string GetMonthName(string monthNum)
{
return culture.DateTimeFormat.GetMonthName(Convert.ToInt32(monthNum));
}
GridView:
<ItemTemplate>
<%# GetMonthName(Eval("theMonth").ToString())%>
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList ID="ddlMonth" runat="server" SelectedValue='<%# Bind("theMonth")%>'>
<asp:ListItem Value="1" Text="תשרי"></ListItem>
etc...
</asp:DropDownList>
</EditItemTemplate>
In your EditTemplate have a DropDownList with ListItems: value="1" Text="תשרי" etc.. so that it's the month number that's passed to your data layer for edits.