Dropdown column in a datagrid

[kimbred]

I have a datagrid that has a dropdown column. All works fine until I go to edit mode and it seems to forget the original value of the column in the selected row. How can I retain that value in edit mode?????

[Frinavale]

Are you preforming a DataBind in the Page Load event....or in any function that is executed before the Event code occurs in the asp life cycle?

If you are, then your data is being re-bound to the GridView and anything edited will be lost.

[kimbred]

I think I'm getting close. I've found on the internet a procedure that uses the EVAL in the source. The problem is I get an error msg. Please see the attached code.

[Frinavale]

Please post your code instead of using attachments.
Attachments are not working at this time.

Also, please post the error message that you are getting....stating that an error occurs is not going to help us in understanding the problem that you're having.

[kimbred]

<asp:GridView ID="GridView1" runat="server" Height="205px" Style="z-index: 102; left: 19px;
        position: absolute; top: 28px" Width="325px" BorderStyle="None" TabIndex="11" AutoGenerateColumns="False" DataSourceID="PhoneList" OnRowEditing="GridView1_RowEditing" OnRowDeleting="GridView1_RowDeleting" BackColor="White" BorderColor="#999999" BorderWidth="1px" CellPadding="3" GridLines="Vertical" OnRowUpdating="GridView1_RowUpdating" OnSelectedIndexChanged="ddlSuper_SelectedIndexChanged" OnRowDataBound="GridView1_RowDataBound" OnRowDeleted="GridView1_RowDeleted">
        <Columns>
            <asp:CommandField ShowDeleteButton="True" ShowEditButton="True" ButtonType="Image" DeleteImageUrl="~/App_Themes/Default/Images/Delete16x16.gif" EditImageUrl="~/App_Themes/Default/Images/SelectEdit.gif" InsertText="" NewText="" CancelImageUrl="~/App_Themes/Default/Images/Reject16x16.gif" UpdateImageUrl="~/App_Themes/Default/Images/Approve16x16.gif" />
            <asp:TemplateField HeaderText="Seq" ShowHeader="False" Visible="False">
                <EditItemTemplate>
                    <asp:TextBox ID="txtSeq" runat="server" Text='<%# Bind("WPRCK7") %>' Visible="False"></asp:TextBox>
                </EditItemTemplate>
                <ItemTemplate>
                    <asp:Label ID="lblSeq" runat="server" Text='<%# Bind("WPRCK7") %>' Visible="False"></asp:Label>
                </ItemTemplate>
            </asp:TemplateField>
            <asp:TemplateField HeaderText="Type">
                <EditItemTemplate>
                    <asp:DropDownList ID="ddlType" runat="server"  SelectedValue='<%# Eval("WPPHTP")%>' DataSourceID="PhoneTypes" DataValueField="DRKY" DataTextField="DRDL01"> </asp:DropDownList> 
                    <asp:ObjectDataSource ID="PhoneTypes" runat="server" SelectMethod="GetPhoneTypes" TypeName="Intranet.DAL.SelfServiceSql"></asp:ObjectDataSource>
                </EditItemTemplate>
                <ItemTemplate>
                   <asp:Label ID="lblPType" runat="server" Text='<%# Bind("WPPHTP") %>'></asp:Label>
                </ItemTemplate>
            </asp:TemplateField>
            <asp:TemplateField HeaderText="Area Cd">
                <EditItemTemplate>
                    <asp:TextBox ID="txtACode" runat="server" Text='<%# Bind("WPAR1") %>'></asp:TextBox>
                </EditItemTemplate>
                <ItemTemplate>
                    <asp:Label ID="lblACode" runat="server" Text='<%# Bind("WPAR1") %>'></asp:Label>
                </ItemTemplate>
            </asp:TemplateField>
            <asp:TemplateField HeaderText="Nbr">
                <EditItemTemplate>
                    <asp:TextBox ID="txtPNbr" runat="server" Text='<%# Bind("WPPH1") %>'></asp:TextBox>
                </EditItemTemplate>
                <ItemTemplate>
                    <asp:Label ID="lblPNbr" runat="server" Text='<%# Bind("WPPH1") %>'></asp:Label>
                </ItemTemplate>
            </asp:TemplateField>
        </Columns>
        <FooterStyle BackColor="#CCCCCC" ForeColor="Black" />
        <RowStyle BackColor="#EEEEEE" ForeColor="Black" />
        <PagerStyle BackColor="#999999" ForeColor="Black" HorizontalAlign="Center" />
        <SelectedRowStyle BackColor="#008A8C" Font-Bold="True" ForeColor="White" />
        <HeaderStyle BackColor="#000084" Font-Bold="True" ForeColor="White" />
        <AlternatingRowStyle BackColor="Gainsboro" />
    </asp:GridView>

I get the following error:
DataBinding: 'System.Data.DataRowView' does not contain a property with the name 'WPPHTP'.

[bhupinder]

Hi
You can use this code.

<asp:DataGrid runat=server id=gvfilesdata>
                        <Columns>
                        <asp:TemplateColumn>
 <ItemTemplate>
                                     <asp:DropDownList ID="ddPage" runat=server Width="150px">
<asp:listitem text='1' value='1'></asp:listitem>
<asp:listitem text='2' value='2'></asp:listitem>
</asp:DropDownList>
 
</itemtemplate>
</asp:TemplateColumn>
 
 
 
                        </Columns>
 
</asp:datagrid>
 

//You can perform this code rowediting of datagrid..



Code of vb

 Protected Sub gvFilesData_RowEditing(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewEditEventArgs) Handles gvFilesData.RowEditing
              Dim id As Integer
 
 
        pageid = CType(gvFilesData.Rows(e.NewEditIndex).Cells(4).FindControl("ddPage"), DropDownList).SelectedValue
              CType((gvFilesData.Rows(e.NewEditIndex).Cells(4).FindControl("ddPage")), DropDownList).SelectedValue = pageid
        bindDataOfFileUpload()
    End Sub

Please implement this code.

[kimbred]

The dropdown list must remain dynamic

[Frinavale]

Take the Eval statement out.
The GridView uses it's data source's properties and methods to bind to.
It's trying to bind the data to DataRowView, which obviously does not have a property named "WPPHTP".

Instead, implement a method that handles the GridView's RowDataBound event and set the selected item in the DropDownList here.

[kimbred]

Do you have an example you could provide? I've tried other methods of setting the value of this column in edit mode, but can't get it right. Any help would be appreciated.

[Frinavale]

Not really....each implementation of the RowDataBound event is going to be different depending on your datasource and what your GridView is meant to display.

Check out the GridView RowDataBound event for more information.

[kimbred]

The article really didn't give me much in regard to setting the initial value of the column. When I use the code below, I get the Title of the row but nothing more. How do you get the value of the selected column?

[Frinavale]

Ok, in typing a response I realized where I made the mistake in attempting to help you....sorry.


You shouldn't be looking at the RowDataBound Event.
I think you should be looking at the Editing Event.

It is here that you want to set the selected value of the DropDownList.

Sub GridView1_RowEditing(ByVal sender As Object, ByVal e As GridViewEditEventArgs) Handles GridView1.RowEditing
    GridView1.EditIndex = e.NewEditIndex
    Dim thisRowsDdlType As DropDownList = Ctype(GridView1.Rows(e.NewEditIndex).FindControl(ddlType), DropDownList)
    thisRowsDdlType.Items(thisRowsDdlType.Items(thisRowsDdlType.SelectedIndex)).Selected = False
 
    thisRowsDdlType.Items(3).Selected = True
 
End Sub

If this doesn't work, then you need to do something similar, only in the RowDataBound event instead.

[kimbred]

Is there somthing similar in C#?

[Frinavale]

I'm not great with C#...it would be just as hard for me to change the syntax into C# as it would be for you.

But if you really want an example in C# please check out the links I showed you.


Here goes my attempt (not guaranteed to work...but you'll get the idea):

void GridView1_RowEditing(Object sender, GridViewEditEventArgs e)
{
    GridView1.EditIndex = e.NewEditIndex;
    DropDownList thisRowsDdlType  = (DropDownList) GridView1.Rows[e.NewEditIndex].FindControl(ddlType);
    thisRowsDdlType.Items[thisRowsDdlType.Items[thisRowsDdlType.SelectedIndex]].Selected = false;
 
    thisRowsDdlType.Items[3].Selected = true;
 
}

[kimbred]

What is the following line in your code attempting to do?

DropDownList thisRowsDdlType = (DropDownList) GridView1.Rows[e.NewEditIndex].FindControl("ddlType");

[Frinavale]

Declare a DropDownList named thisRowsDdlType.

Uses the FindControl method on the GridView1 e.NewEditIndex Row to retrieve the DropDownList located in that row...

Since the FindControl method returns an Object, it casts it into a DropDownList.

So, basically it declares a DropDownList and retrieves the DropDownList found in the row being edited.

Is there something wrong with it?

[kimbred]

Error 10 Argument '1': cannot convert from 'System.Web.UI.WebControls.ListItem' to 'int' C:\Projects\Intranet\Intranet_Web\SelfService\Cont rols\PersonalInfo.ascx.cs 403 31

[kimbred]

I don't think it's finding the control

[kimbred]

This is the line I'm getting the error on.

thisRowsDdlType.Items[thisRowsDdlType.Items[thisRowsDdlType.SelectedIndex]].Selected = false;

[Frinavale]

Just remove that line then.

It's to make sure that any selection in the DropDownList is deselected before selecting the new item. I don't think that your DropDownList will have a selection at that point.

[bhupinder]

@kimbred
Yes, you can do this way

<asp:datagrid id='gvfilesdata' runat=server>
<column>
<asp:TemplateColumn>
  <ItemTemplate>
      <asp:DropDownList ID="ddlanguage" runat=server Width="150px"></asp:DropDownList>
  </ItemTemplate>
  </asp:TemplateColumn>
</column>
</asp:datagrid>

Code of vb

    Protected Sub gvFilesData_ItemDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.DataGridItemEventArgs) Handles gvFilesData.ItemDataBound
        If e.Item.ItemType = ListItemType.Item Then
       Dim query As String
 
            query = "select * from tbl_language"
 
'************* con of connection string name*****
dim adp as new sqldataadpater(query,con)
 
dim ds as new dataset
 
         adp.fill(ds)
            If ds.Tables(0).Rows.Count > 0 Then
                CType((e.Row.Cells(0).FindControl("ddLanguage")), DropDownList).DataSource = ds
                CType((e.Row.Cells(0).FindControl("ddLanguage")), DropDownList).DataTextField = "lang_name"
                CType((e.Row.Cells(0).FindControl("ddLanguage")), DropDownList).DataValueField = "lang_id"
                CType((e.Row.Cells(0).FindControl("ddLanguage")), DropDownList).DataBind()
            End If
            ds.Dispose()
 
        End If
    End Sub
 
  Protected Sub gvFilesData_RowEditing(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewEditEventArgs) Handles gvFilesData.RowEditing
        Dim pageid, id As Integer
 
 
        pageid = CType(gvFilesData.Rows(e.NewEditIndex).Cells(0).FindControl("ddlanguage"), DropDownList).SelectedValue
 
        CType((gvFilesData.Rows(e.NewEditIndex).Cells(0).FindControl("ddlanguage")), DropDownList).SelectedValue = pageid
        bindDataOfFileUpload()
    End Sub

[kimbred]

If the following line of code gets the correct existing value, how does one go about setting the index of a dropdown thats buried like this is?

string oldvalue = ((Label)row.Cells[2].FindControl("lblType")).Text.Trim();

[bhupinder]

@kimbred


Sorry kimbred,
i am not able to get your question. Can you explain again?