Hannes Preishuber

# re: Gridview and dropdownlist:the missing value

# re: Gridview and dropdownlist:the missing value

# re: Gridview and dropdownlist:the missing value

I completely agree with the June 12 post by David

Its not that we can't find work arounds for these type of problems, its the fact that we have to literally count the years go by before these issues are addressed. Why can't Microsoft fix these problems at the source?

# re: Gridview and dropdownlist:the missing value

what causes this error when the items do exist.

I have been trying to fix the error but the data is corect and the items exist in the list and data -it looks like it thinks it is blank

# re: Gridview and dropdownlist:the missing value

I had the same apparent problem, RJ, where even if the value was there I'd get the missiing value error. THen I found this guys article where he besically scrpas the binding, finds the databound item in the code behind on dropdown databound and does the value selection there. Worked great for me:

http://www.webswapp.com/CodeSamples/viewsource.aspx?file=~/codesamples/aspnet20/dependentlists/default.aspx

# dropdowwnlist

how to compare two dropdowwnlist values with each other

# re: Gridview and dropdownlist:the missing value

This solution doesn't work for me. when i click edit it doesnot check

If e.Row.RowState = (DataControlRowState.Edit Or DataControlRowState.Selected) Then

End IF

And Error is.............

'ddlCustomerCountry' has a SelectedValue which is invalid because it does not exist in the list of items.

Parameter name: value

# re: Gridview and dropdownlist:the missing value

I have some Question to you "How to get the selected text of dropdownlist exist in gridview"

# re: Gridview and dropdownlist:the missing value

how to compare two dropdowwnlist values with each other

# re: Gridview and dropdownlist:the missing value

A little help more, for a novice.

ON the 'setting of the ListBox's selected-item', which EVENT is this code placed into?

I have tried gvw_DataBinding, gvw_DataBinding events and I get 'syntax-error' on 'e.RowIndex' is undefined property.

# re: Gridview and dropdownlist:the missing value

Was having a bad day and your artical made it better i forgot about rowstate!!!!!! and couldn't figure out an error

Thanks!!!

# DropDownLists and the Selected Value Not In List problem

Pingback from  DropDownLists and the Selected Value Not In List problem

# re: Gridview and dropdownlist:the missing value

to explain fields in my code, "driver" is the field that I am binding to in the database, "glTrucks" is my gridview, and "ddlTruckDrivers1" is my template dropdownlist that I am trying to compensate for values that have been deleted from the database.

Here's what I did to solve this:  

1. Deleted the "selected value="<%# bind("driver") %>" from the

dropdownlist. (i did not have this code in my above posting)

2. Placed "Imports System.Data" at the top of my code page to

accomodate for the "DataRowView"

3. Entered the following code in my dropdownlist_databound.  I got

this code from teh following website:

www.webswapp.com/.../default.aspx

(he has codebehind in C# or VB)

Protected Sub ddlTruckDrivers1_DataBound(ByVal sender As Object,

ByVal e As System.EventArgs)

       Dim ddl As DropDownList = DirectCast(sender, DropDownList)

       '===  add an empty item on top of the list

       Dim gvRow As GridViewRow = DirectCast(ddl.NamingContainer,

GridViewRow)

'check to see if the item exists in the gridview, if it doesn't then

it will default to the first item in the dropdownlist

       If Not gvRow.DataItem Is Nothing Then

           Dim strDriver As String = DirectCast(gvRow.DataItem,

DataRowView)("driver").ToString

           'be careful of the possibility that the value saved on

the  database does not exist

           'in the valid selections that are displayed on the list

           ddl.ClearSelection()

           Dim li As ListItem = ddl.Items.FindByValue(strDriver)

           If Not li Is Nothing Then li.Selected = True

       End If

   End Sub

4. This small piece of data to set the value of the update parameter:

   Protected Sub glTrucks_RowUpdating(ByVal sender As Object, ByVal e

As System.Web.UI.WebControls.GridViewUpdateEventArgs) Handles

glTrucks.RowUpdating

       e.NewValues("driver") =

CType(glTrucks.Rows(e.RowIndex).FindControl("ddlTruckDrivers1"),

DropDownList).SelectedValue

   End Sub

# re: Gridview and dropdownlist:the missing value

Thanks so much for this code.  I just have one question. If my dropdown list's datatextfield is different than my datavalue field what would I need to change in the code?  I keep getting an 'Object reference not set to an instance of an object.' error and I think its because of the above.  My datavalue field is "OthHoursCode" and my datatextfield is "Desc".

Thanks.

# re: Gridview and dropdownlist:the missing value

As I'm fairly new to asp.net with more strength with T-SQL, I've solved this in SQL.

For the select statement which populates the drop down, I've created a custom SQL statment in the SQLDataSource which first counts the number of rows matching the search criteria.  If 0, a NULL based record is returned, otherwise the normal results set is provided.  i.e.:

IF (SELECT COUNT(*) FROM admin_attribute_option WHERE AttributeCode = @vAttrCode) = 0

BEGIN

SELECT

NULL AS OptionCode,

'SELECT VALUE' AS OptionDesc

END

ELSE

BEGIN

SELECT

OptionCode,

OptionDesc

FROM

admin_attribute_option

WHERE

AttributeCode = @vAttrCode

END

When it comes to your update / insert statements, remember to test for the NULL value coming back otherwise your page will error out.  e.g.

IF LEN(RTRIM(@OptionCode)) > 0

BEGIN

DELETE FROM

product_attributes

WHERE

ProdCode = @ProdCode

AND

AttributeCode = @AttributeCode

INSERT INTO

product_attributes

(

ProdCode, AttributeCode, OptionCode, LoginID

)

SELECT

@ProdCode,

@AttributeCode,

@OptionCode,

'TEST'

END