Solved

Gridview dropdown - bind record source in code

Posted on 2011-09-07
9
432 Views
Last Modified: 2012-05-12
I am trying to bind the recordsource of a dropdownlist to a datasource in code. The datasource is dependend on the value in a cell.
With this code I get the error: Databinding can only be used in the context of a databound control.

 
<asp:TemplateField HeaderText="Action">    
                    <EditItemTemplate>
                        <asp:DropDownList ID="ddlAction" runat="server" SelectedValue='<%# Bind("Action") %>' DataSourceID="objActionTypes"></asp:DropDownList>
                    </EditItemTemplate>
                    <ItemTemplate>
                        <asp:Label ID="Label1" runat="server" Text='<%# Bind("Action") %>'></asp:Label>
                    </ItemTemplate>
                </asp:TemplateField>  
                <asp:CommandField ShowEditButton="True" ButtonType="Button"/>


 protected void gvReport_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            if (e.Row.RowType == DataControlRowType.DataRow)
            {
                string strStatus = DataBinder.Eval(e.Row.DataItem, "Status").ToString();

                if (gvReportLines.EditIndex == e.Row.RowIndex && e.Row.RowType == DataControlRowType.DataRow)
                {
                    DropDownList drpBuild = (DropDownList)e.Row.Cells[0].FindControl("ddlStatus");

                    if (strStatus == "Standby")
                        drpBuild.DataSourceID = "objStatusTypesAll";
                    else
                        drpBuild.DataSourceID = "objStatusTypes";
                }
            }
        }

Open in new window

0
Comment
Question by:edaj6
  • 5
  • 4
9 Comments
 

Author Comment

by:edaj6
ID: 36494013
Sorry, I posted the wrong template field. Here is the right one.

<asp:TemplateField HeaderText="Status">    
                    <EditItemTemplate>
                        <asp:DropDownList ID="ddlStatus" runat="server" DataValueField="StatusType" AppendDataBoundItems="true" 
                        EnableViewState="True"  SelectedValue='<%# Bind("Status") %>' DataSourceID="objStatusTypes"></asp:DropDownList>
                    </EditItemTemplate>
                    <ItemTemplate>
                        <asp:Label ID="Label1" runat="server" Text='<%# Bind("Status") %>'></asp:Label>
                    </ItemTemplate>
                    <AlternatingItemTemplate></AlternatingItemTemplate> 
                    </asp:TemplateField>

Open in new window

0
 
LVL 16

Accepted Solution

by:
Easwaran Paramasivam earned 500 total points
ID: 36494213
Bind dropdownlist in the grid's OnRowCreated event.
 OnRowCreated="gvStates_RowCreated".

For more details look at: http://webthingsconsidered.blogspot.com/2005/09/dropdownlist-inside-gridview-or.html

0
 

Author Comment

by:edaj6
ID: 36494310
I get an error on line:
drpBuild.DataSourceID = "objStatusTypesAll";

Stack Trace:
[NullReferenceException: Object reference not set to an instance of an object.]

The example in link is not setting the datasource to a DataSourceID, is this not possible?
0
Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

 
LVL 16

Assisted Solution

by:Easwaran Paramasivam
Easwaran Paramasivam earned 500 total points
ID: 36494331
Better set DataSource. Refer the link: http://forums.asp.net/t/1311963.aspx/1
0
 

Author Comment

by:edaj6
ID: 36494438
Ok thanks. The ddlStatus control can't be found, is this because it's in an edit template?

if (e.Row.RowType == DataControlRowType.DataRow)
                {
                    DropDownList ddl = (DropDownList)e.Row.FindControl("ddlStatus");
                    ddl.DataSource = BLL.EquipErrorManager.GetStatusTypesAll();
                    ddl.DataBind();

...
0
 
LVL 16

Expert Comment

by:Easwaran Paramasivam
ID: 36494477
Whether your previous code DropDownList drpBuild = (DropDownList)e.Row.Cells[0].FindControl("ddlStatus"); was working properly? If so, use the same.
0
 

Author Comment

by:edaj6
ID: 36494714
No not working, just tried to but on item template instead and then it can be found. It can't find a control in an edit template.

When I set Datasource in code is it fine to set selected value in  grid? SelectedValue='<%# Bind("Status") %>'>
0
 
LVL 16

Assisted Solution

by:Easwaran Paramasivam
Easwaran Paramasivam earned 500 total points
ID: 36494837
No.  SelectedValue can't be set in that way.  Use any one of below code.

ddl.SelectedIndex = Yourindex;  

ddl.SelectedValue = YourValue;
0
 

Author Comment

by:edaj6
ID: 36495329
Thankyou for comments, I got a bit futher.

I got the code to work in row_databound, cant do it on row_created since it cant find the control in edit template. The drop down works, but when I click update it can't find the value for status.

 
if (e.Row.RowType == DataControlRowType.DataRow && e.Row.RowIndex == gvReportLines.EditIndex)
            {
                string strStatus = DataBinder.Eval(e.Row.DataItem, "Status").ToString();
                DropDownList ddl = (DropDownList)e.Row.FindControl("ddlStatus");
                
                if (strStatus == "Standby")
                    ddl.DataSource = BLL.EquipErrorManager.GetStatusTypesAll();
                else
                    ddl.DataSource = BLL.EquipErrorManager.GetStatusTypes();

                ddl.DataBind();
                ddl.SelectedValue = strStatus;
           }

Open in new window

0

Featured Post

Networking for the Cloud Era

Join Microsoft and Riverbed for a discussion and demonstration of enhancements to SteelConnect:
-One-click orchestration and cloud connectivity in Azure environments
-Tight integration of SD-WAN and WAN optimization capabilities
-Scalability and resiliency equal to a data center

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Just a quick little trick I learned recently.  Now that I'm using jQuery with abandon in my asp.net applications, I have grown tired of the following syntax:      (CODE) I suppose it just offends my sense of decency to put inline VBScript on a…
The article shows the basic steps of integrating an HTML theme template into an ASP.NET MVC project
The Email Laundry PDF encryption service allows companies to send confidential encrypted  emails to anybody. The PDF document can also contain attachments that are embedded in the encrypted PDF. The password is randomly generated by The Email Laundr…

820 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question