Hi,
I am building a DataGrid, which includes a Template Column "ItemText".
When the DataGrid goes into Edit Mode, the datafield in this column is
displayed in a textbox "tbItemText". The text in this field is quite long
(a few thousand words), and contains html tags. I want the user to be
able to make changes in the textbox, and then see what his changes will
look like when displayed in a browser, BEFORE the database itself is
updated.
This is how I'm trying to do it:
1 under the textbox tbItemText in Edit Mode there is a button "Proposed
Item Text".
2 when the user clicks on this button, a Command Event is raised
3 in the subroutine dg_Command, the existing columns of the DataGrid are
made invisible, and a new Template Column (Header: "Proposed Item Text")
is dynamically created.
4 This new dynamic Template Column contains an asp:Label Control,
id="lbProposedItemText". This label is loaded from a separate
file "TEMPLATE.ASCX" via thePage.LoadTemplate("Template.ascx") method.
5 lbProposedItemText.Text is set to equal tbItemText.Text, thus showing
the user the results of his proposed changes to ItemText.
I am having a problem with step 5 - when the dynamically created Template
Column is shown, the Label lbProposedItemText has NO Text attached to it.
Can anyone tell me why?
Thanks!
JON
************************************************************************
THE CODE
************************************************************************
THE WHOLE LISTING IS QUITE LONG - HERE'S JUST THE SUBROUTINE TO HANDLE THE
COMMAND EVENT RAISED WHEN THE "PROPOSED ITEM TEXT" BUTTON IS CLICKED:
sub dg_command(sender as object, e as DataGridCommandEventArgs)
If e.CommandSource.Text = "View Proposed Changes"
Dim tc as new TemplateColumn()
tc.HeaderText="Proposed Item Text"
tc.ItemTemplate = Page.LoadTemplate("Template.ascx")
dg.Columns(0).visible = False
dg.Columns(1).visible = False
dg.Columns(2).visible = False
dg.Columns(3).visible = False
dg.Columns(4).visible = False
dg.Columns.Add(tc)
If (e.Item.ItemType = ListItemType.Item) or (e.Item.ItemType =
ListItemType.AlternatingItem) then
Dim lbProposedItemText As Label = e.Item.FindControl("lbProposedItemText")
Dim tbItemText As TextBox = e.Item.FindControl("tbItemText")
lbProposedItemText.Text = tbItemText.Text
'THIS IS NOT WORKING FOR SOME REASON
end if
dg.DataBind()
end if
end sub
HERE ARE THE FULL LISTINGS OF THE ASCX PAGE AND THE MAIN DATAGRID PAGE:
+++++++++++++++++++++++++++++
TEMPLATE.ASCX
+++++++++++++++++++++++++++++
<%@ Control Language="VB" %>
<asp:Label id="lbProposedItemText" runat="server" />
+++++++++++++++++++++++++++++
MAIN PAGE
+++++++++++++++++++++++++++++
<%@ Page Language="VB" Debug="true" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.Oledb" %>
<%@ Reference Control="Template.ascx" %>
<script language="VB" runat="server">
Dim objConn as New OleDbConnection ( ConfigurationSettings.AppSettings
("ConnectionString") )
Dim ds as Dataset = New DataSet()
Dim objAdapter as New OleDbDataAdapter ( "SELECT * from tblItems;",
objConn )
Sub Page_Load(sender as object, e as eventargs)
objConn.Open()
objAdapter.Fill(ds, "tblItems")
dg.DataSource = ds
dg.DataMember = "tblItems"
If Not Page.IsPostBack Then
dg.Databind()
End If
End Sub
function EscapeString(str)
'Used to prevent HTML from being entered and to escape any quotation
'marks, necessary so the values can be specified in an input field
str = replace(str, "'", "''")
escapeString = str
end function
Sub myDataGrid_ItemDataBound(sender As Object, e As DataGridItemEventArgs)
If (e.Item.ItemType = ListItemType.Item) or (e.Item.ItemType =
ListItemType.AlternatingItem) then
Dim hlViewItemText as new Hyperlink
Dim lbItemId As Label = e.Item.FindControl("lbItemID")
hlViewItemText.NavigateURL="ViewItemText.aspx?ItemID=" & lbItemID.Text
hlViewItemText.Text="ViewItemText"
e.Item.FindControl("HyperLinkPlaceHolder").Controls.Add(hlViewItemText)
End if
'WHEN IN EDIT MODE, Set the SelectedIndex of the ItemType DropDownList to
current ItemType
If e.Item.ItemType = ListItemType.EditItem then
Dim ddItemType as DropDownList = e.Item.FindControl("ddItemType")
Dim lbItemType as Label = e.Item.FindControl("lbItemType")
'lbItemType is a non-visible Label, only in the EditItemTemplate so I can
grab the value here!
ddItemType.Items.FindByText(lbItemType.Text).Selected = true
End if
End sub
sub dg_edit(sender as object, e as DataGridCommandEventArgs)
dg.edititemindex = e.item.itemindex
dg.databind()
end sub
sub dg_cancel(sender as object, e as DataGridCommandEventArgs)
dg.edititemindex = -1
dg.databind()
end sub
sub dg_update(sender as object, e as DataGridCommandEventArgs)
Dim tbItemTitle As TextBox = e.Item.FindControl("tbItemTitle")
Dim tbItemDescription As TextBox = e.Item.FindControl("tbItemDescription")
Dim tbItemText As TextBox = e.Item.FindControl("tbItemText")
Dim lbItemId As Label = e.Item.FindControl("lbItemID")
Dim strSQL As String = "UPDATE tblItems SET ItemTitle = '" &
tbItemTitle.Text & "', ItemDescription = '" & tbItemDescription.Text
& "' , ItemText = '" & EscapeString(tbItemText.Text) & "' WHERE ItemID = "
& lbItemID.Text
'This throws an error if ItemText is empty - but not ALL items WILL have a
text!
Dim objCommand as New OleDbCommand(strSQL, objConn)
objCommand.ExecuteNonQuery()
ds.Tables.Clear
objAdapter.Fill(ds, "tblItems")
dg.edititemindex = -1
dg.DataBind()
end sub
sub dg_command(sender as object, e as DataGridCommandEventArgs)
'**************************************************************************
***
'PROBLEM HERE - WANT TO DYNAMICALLY ADD A TEMPLATE COLUMN WITH A
LABEL "PROPOSEDITEMTEXT"
'THEN SET THE TEXT PROPERTY OF THIS LABEL TO EQUAL THE TEXT PROPERTY
'OF THE TEXTBOX ITEMTEXT (FROM ANOTHER COLUMN)
'**************************************************************************
***
If e.CommandSource.Text = "View Proposed Changes"
Dim tc as new TemplateColumn()
tc.HeaderText="Proposed ItemText"
tc.ItemTemplate = Page.LoadTemplate("Template.ascx")
dg.Columns(0).visible = False
dg.Columns(1).visible = False
dg.Columns(2).visible = False
dg.Columns(3).visible = False
dg.Columns(4).visible = False
dg.Columns.Add(tc)
If (e.Item.ItemType = ListItemType.Item) or (e.Item.ItemType =
ListItemType.AlternatingItem) then
Dim lbProposedItemText As Label = e.Item.FindControl("lbProposedItemText")
Dim tbItemText As TextBox = e.Item.FindControl("tbItemText")
lbProposedItemText.Text = tbItemText.Text
'THIS IS NOT WORKING FOR SOME REASON
end if
dg.DataBind()
end if
end sub
</script>
<html>
<head>
<link rel="STYLESHEET" type="text/css" href="Forum.css">
</head>
<body>
<form runat="server">
<asp:DataGrid id="dg" runat="server"
Bordercolor="black"
gridlines="vertical"
font-names="Arial"
font-size="10pt"
cellpadding="4"
cellspacing="0"
width="100%"
ShowFooter="True"
HeaderStyle-BackColor="#cccc99"
FooterStyle-BackColor="#cccc99"
ItemStyle-BackColor="#ffffff"
AlternatingItemStyle-Backcolor="#cccccc"
AutoGenerateColumns="False"
OnItemDataBound="myDataGrid_ItemDataBound"
OnEditCommand="dg_edit"
OnCancelCommand="dg_cancel"
OnUpdateCommand="dg_update"
OnItemCommand="dg_command"
>
<Columns>
<asp:editcommandcolumn HeaderText="EDIT" edittext="Edit"
CancelText="Cancel" UpdateText="Save" HeaderText="" />
<%-- ITEMID; ITEMTYPEID; ITEMTYPE; ITEMTITLE --%>
<asp:TemplateColumn ItemStyle-VerticalAlign="top" HeaderText="Various">
<ItemTemplate>
<asp:Table CSSClass="TableStyle1" runat="server">
<asp:TableRow>
<asp:TableCell><b>ItemID: </b></asp:TableCell><asp:TableCell><asp:Label
id="lbItemID" Text ='<%# DataBinder.Eval(Container.DataItem, "ItemID") %>'
runat="server" /></asp:TableCell>
<%-- this was originally a bound column, and I was tracking down the
ItemID value with e.Item.Cells(1).Text - problem was, if I changed the
columns around, I had to manually change the column number, so am now
doing it dynamically --%>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>ItemTypeID:
</b></asp:TableCell><asp:TableCell><asp:Label runat="server" Text='<%#
Container.DataItem("ItemTypeID") %>' /></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>ItemType: </b></asp:TableCell><asp:TableCell><asp:Label
runat="server" Text='<%# Container.DataItem("ItemType") %
>' /></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>ItemTitle: </b></asp:TableCell><asp:TableCell><asp:Label
runat="server" Text='<%# Container.DataItem("ItemTitle") %
>' /></asp:TableCell>
</asp:TableRow>
</asp:Table>
</ItemTemplate>
<EditItemTemplate>
<asp:Table CSSClass="TableStyle1" runat="server">
<asp:TableRow>
<asp:TableCell><b>ItemID: </b></asp:TableCell><asp:TableCell><asp:Label
id="lbItemID" Text ='<%# DataBinder.Eval(Container.DataItem, "ItemID") %>'
runat="server" /></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>ItemTypeID:
</b></asp:TableCell><asp:TableCell><asp:Textbox id="tbItemTypeID"
runat="server" Text='<%# Container.DataItem("ItemTypeID") %
>' /></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>ItemType: </b></asp:TableCell><asp:TableCell><asp:Label
runat="server" id="lbItemType" Visible="false" Text='<%# Container.DataItem
("ItemType") %>' /><asp:DropDownList id="ddItemType" runat="server"
DataSource='<%# ds.Tables("tblItems").DefaultView %>'
DataTextField="ItemType" /></asp:TableCell>
<%-- This row contains a non-visible Label, simply there so I can grab
the "current" ItemType from it and set the Selected Item of the Drop Down
to this value --%>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>ItemTitle:
</b></asp:TableCell><asp:TableCell><asp:Textbox id="tbItemTitle"
runat="server" Text='<%# Container.DataItem("ItemTitle") %
>' /></asp:TableCell>
</asp:TableRow>
</asp:Table>
</EditItemTemplate>
</asp:TemplateColumn>
<%-- ITEM DESCRIPTION --%>
<asp:TemplateColumn HeaderText="ItemDescription">
<ItemTemplate>
<asp:Label runat="server" Text='<%# Container.DataItem("ItemDescription")%
>' />
</ItemTemplate>
<EditItemTemplate>
<asp:Textbox id="tbItemDescription" runat="server" Textmode="MultiLine"
Columns="30" Rows="8" Text='<%# Container.DataItem("ItemDescription") %
>' />
</EditItemTemplate>
</asp:TemplateColumn>
<%-- ITEM TEXT --%>
<asp:TemplateColumn HeaderText="ItemText">
<ItemTemplate>
<asp:TextBox runat="server" ReadOnly="True" Textmode="MultiLine"
Columns="30" Rows="8" Text='<%# Container.DataItem("ItemText") %>' />
<br/>
<asp:Placeholder runat="server" id="HyperLinkPlaceholder" />
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox id="tbItemText" runat="server" Textmode="MultiLine"
Columns="30" Rows="8" BackColor="red" Text='<%# Container.DataItem
("ItemText") %>' />
<br/>
<asp:Button runat="server" id="btViewItemText" Text="View Proposed
Changes"/>
</EditItemTemplate>
</asp:TemplateColumn>
<%-- POSTEDBY; POSTEDDATE; ITEMPARENT; SORTORDER;
ITEMRATING; MODERATED; JPTOREPLY --%>
<asp:TemplateColumn ItemStyle-VerticalAlign="top" HeaderText="Various">
<ItemTemplate>
<asp:Table CSSClass="TableStyle1" runat="server">
<asp:TableRow>
<asp:TableCell><b>PostedBy: </b></asp:TableCell><asp:TableCell><asp:Label
runat="server" Text='<%# Container.DataItem("PostedBy") %
>' /></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>PostedDate:
</b></asp:TableCell><asp:TableCell><asp:Label runat="server" Text='<%#
Container.DataItem("PostedDate") %>' /></asp:TableCell>
<%-- COULD do this dynamically, finding the values directly from the
DataSet - see above --%>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>ItemParent:
</b></asp:TableCell><asp:TableCell><asp:Label runat="server" Text='<%#
Container.DataItem("ItemParent") %>' /></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>SortOrder: </b></asp:TableCell><asp:TableCell><asp:Label
runat="server" Text='<%# Container.DataItem("SortOrder") %
>' /></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>ItemRating:
</b></asp:TableCell><asp:TableCell><asp:Label runat="server" Text='<%#
Container.DataItem("ItemRating") %>' /></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>Moderated?:
</b></asp:TableCell><asp:TableCell><asp:CheckBox runat="server"
Enabled="false" Checked='<%# Container.DataItem("ModeratedYN") %
>' /></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>JPToReply?:
</b></asp:TableCell><asp:TableCell><asp:CheckBox runat="server"
Enabled="false" Checked='<%# Container.DataItem("JPStillToReplyYN") %
>' /></asp:TableCell>
</asp:TableRow>
</asp:Table>
</ItemTemplate>
<EditItemTemplate>
<asp:Table CSSClass="TableStyle1" runat="server">
<asp:TableRow>
<asp:TableCell><b>PostedBy:
</b></asp:TableCell><asp:TableCell><asp:Textbox runat="server"
width="100px" Text='<%# Container.DataItem("PostedBy") %
>' /></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>PostedDate:
</b></asp:TableCell><asp:TableCell><asp:Textbox runat="server"
width="100px" Text='<%# Container.DataItem("PostedDate") %
>' /></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>ItemParent:
</b></asp:TableCell><asp:TableCell><asp:Textbox runat="server"
width="100px" Text='<%# Container.DataItem("ItemParent") %
>' /></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>SortOrder:
</b></asp:TableCell><asp:TableCell><asp:Textbox runat="server"
width="100px" Text='<%# Container.DataItem("SortOrder") %
>' /></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>ItemRating:
</b></asp:TableCell><asp:TableCell><asp:Textbox runat="server"
width="100px" Text='<%# Container.DataItem("ItemRating") %
>' /></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>Moderated?:
</b></asp:TableCell><asp:TableCell></strong><asp:CheckBox runat="server"
Enabled="true" Checked='<%# Container.DataItem("ModeratedYN") %
>' /></asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell><b>JPToReply?:
</b></asp:TableCell><asp:TableCell></strong><asp:CheckBox runat="server"
Enabled="true" Checked='<%# Container.DataItem("JPStillToReplyYN") %
>' /></asp:TableCell>
</asp:TableRow>
</asp:Table>
</EditItemTemplate>
</asp:TemplateColumn>
</Columns>
</asp:dataGrid>
</form>
</body></html>
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