I am using AJAX TabContainer and have an asp GridView in each tab which is bound to an ObjectDataSource. The ObjectDataSource returns different objects based on the tab selected (TabContainer AutoPostBack="True"). I bind the ObjectDataSource to the GridView based on the tab selected during TabContainer Load in the code behind only if IsPostBack because on the first load the TabContainer is not visible. I do not bind the GridView anywhere else. The fields in the GridView are Eval instead of Bind because the parameters are added to the ObjectDataSource dinamically.
This is a bulk update GridView with all of the fields editable. When I update the GridView, I am not able to see e.OldValues. If the fields in the GridView are set to Bind, I am able to retrieve e.NewValues nut e.OldValues is still empty...
Does anyone know what the deal is?
<asp:ObjectDataSource ID="odsEquipment" runat="server" TypeName="EquipmentDB" SelectMethod="GetEquipment" SortParameterName="sortExpression" UpdateMethod="UpdateEquipment">
<SelectParameters>
--Params
</SelectParameters>
<UpdateParameters>
--Params
</UpdateParameters>
</asp:ObjectDataSource>
<asp:TabContainer ID="tcDisciplines" runat="server" CssClass="ajax_tabController" ScrollBars="Horizontal" AutoPostBack="True">
--Tabs and GridViews with no properties
Code Behind:
Protected Sub tcDisciplines_Load(sender As Object, e As EventArgs) Handles tcDisciplines.Load
If IsPostBack Then
For Each discipline In disciplineList
tcDisciplines.Tabs(discipline.ID).HeaderText = discipline.Discipline
tcDisciplines.Tabs(discipline.ID).TabIndex = discipline.ID
Dim gv As GridView = TryCast(tcDisciplines.Tabs(discipline.ID).Controls(0).FindControl("gv" + discipline.Abbr), GridView)
gv.Visible = False
If tcDisciplines.ActiveTabIndex = discipline.ID Then
gv.Visible = True
'Set properties
End If
Next
End If
End Sub
Found a little tutorial on MSDN, http://msdn.microsoft.com/en-us/library/aa992036.aspx#Y3473
This work-around helped me. I used a session instead with a list of rows.
Related
ddl2 populates based on ddl1 selected value successfully.
My issue is the data that is already present in ddl2 does not clear before appending the new data so ddl2 content just continues to grow every time ddl1 is changed.
<asp:DropDownList ID="ddl1" RunAt="Server" DataSourceID="sql1" DataValueField="ID1" DataTextField="Name2" AppendDataBoundItems="True" AutoPostBack="True">
<asp:ListItem Text="ALL" Selected="True" Value="0"/>
</asp:DropDownList>
<asp:DropDownList ID="ddl2" RunAt="Server" DataSourceID="sql2" DataValueField="ID2" DataTextField="Name2" AppendDataBoundItems="True" AutoPostBack="True">
<asp:ListItem Text="ALL" Selected="True" Value="0"/>
</asp:DropDownList>
<asp:SqlDataSource ID="sql1" RunAt="Server" SelectCommand="sp1" SelectCommandType="StoredProcedure"/>
<asp:SqlDataSource ID="sql2" RunAt="Server" SelectCommand="sp2" SelectCommandType="StoredProcedure">
<SelectParameters>
<asp:ControlParameter Type="Int32" Name="ID1" ControlID="ddl1" PropertyName="SelectedValue"/>
</SelectParameters>
</asp:SqlDataSource>
I have tried re-databinding in code behind on selected index change and also items.clear with little success.
Protected Sub ddl1_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
ddl2.Items.Clear()
ddl2.DataSource = sql2
ddl2.DataBind()
End Sub
QUESTION
How to get items present in an asp:dropdownlist to clear before new values are populated when the dropdownlists content is dependent on another dropdownlists selected value?
Please post any code in VB
Using ddl.Items.Clear() will clear the dropdownlist however you must be sure that your dropdownlist is not set to:
AppendDataBoundItems="True"
This option will cause the rebound data to be appended to the existing list which will NOT be cleared prior to binding.
SOLUTION
Add AppendDataBoundItems="False" to your dropdownlist.
Now when data is rebound it will automatically clear all existing data beforehand.
Protected Sub ddl1_SelectedIndexChanged(sender As Object, e As EventArgs)
ddl2.DataSource = sql2
ddl2.DataBind()
End Sub
NOTE: This may not be suitable in all situations as appenddatbound items can cause your dropdown to append its own data on each change of the list.
TOP TIP
Still want a default list item adding to your dropdown but need to rebind data?
Use AppendDataBoundItems="False" to prevent duplication data on postback and then directly after binding your dropdownlist insert a new default list item.
ddl.Items.Insert(0, New ListItem("Select ...", ""))
You should clear out your listbbox prior to binding:
Me.ddl2.Items.Clear()
' now set datasource and bind
Please use the following
ddlCity.Items.Clear();
Just 2 simple steps to solve your issue
First of all check AppendDataBoundItems property and make it assign false
Secondly clear all the items using property .clear()
{
ddl1.Items.Clear();
ddl1.datasource = sql1;
ddl1.DataBind();
}
just compiled your code and the only thing that is missing from it is that you have to Bind your ddl2 to an empty datasource before binding it again like this:
Protected Sub ddl1_SelectedIndexChanged(ByVal sender As Object, ByVal
e As EventArgs)
//ddl2.Items.Clear()
ddl2.DataSource=New List(Of String)()
ddl2.DataSource = sql2
ddl2.DataBind() End Sub
and it worked just fine
Background:
I have a GridView which gets populated from an SqlDataSource via DataSourceID. The rows show some summary data from an SQL View. Upon clicking a row, I would like to take my user to another page with a DetailsView control which gets populated with the full set of values from the DB related to the row clicked. My user should be able to edit the data, download files associated with the record, and create a new record of a different type based on said data.
Error:
All examples that I've found for Clickable GridView rows end up with some variation of the error Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%# Page EnableEventValidation="true" %> in a page.
Naturally, I do not want to expose my site to vulnerabilities by disabling event validation. I need to be able to grab the Primary key of the clicked row's associated record and perform operations on that data on a subsequent page, probably via a DetailsView. I suspect my errors are a result of my setup, which is why I included those details.
My Questions Are:
How do I capture the Primary Key of clicked row?
How do I, onclick, forward to a "details" page with a pre-filled form containing data from the row record that was clicked?
HERE'S THE COMPLETE SOLUTION
**thanks again to Icarus' help
'Fetch the DataKey ("ID"), seems to work
Protected Sub RowBind(ByVal sender As Object, ByVal e As GridViewRowEventArgs) _
Handles GridView1.RowDataBound
If e.Row.RowType = DataControlRowType.DataRow Then
Dim datakey As String = GridView1.DataKeys(e.Row.RowIndex).Value.ToString()
End If
End Sub
'Handle button click
Protected Sub RowClick(ByVal sender As Object, ByVal e As GridViewCommandEventArgs) _
Handles GridView1.RowCommand
If e.CommandName = "Select" Then
'Add to session variable; translate the index of clicked to Primary Key
Session.Add("DetailsKey", GridView1.DataKeys(e.CommandArgument).Value.ToString)
Response.Redirect("details.aspx")
End If
End Sub
And My Markup
<asp:GridView ID="GridView1" runat="server" DataSourceID="GridView1SDS"
DataKeyNames="ID" AllowPaging="True" AllowSorting="True">
'<!-- Styling -->
<Columns>
<asp:ButtonField ButtonType="Button" Text="Details" CommandName="Select" />
</Columns>
</asp:GridView>
<asp:SqlDataSource ID="GridView1SDS" runat="server"
ConnectionString="<%$ ConnectionStrings:dbConnectionString %>"
SelectCommand="select * from viewRequestQueue">'<!-- An SQL View -->
</asp:SqlDataSource>
Forwarded Page VB & Markup
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not IsPostBack Then
GridView2SDS.SelectCommand = "select * from viewRequestQueue where ID = " _
+ Session.Item("DetailsKey").ToString
End If
End Sub
<asp:DetailsView ID="GridView2" runat="server" DataSourceID="GridView2SDS">
'<!-- Styling -->
</asp:DetailsView>
<asp:SqlDataSource ID="GridView2SDS" runat="server"
ConnectionString="<%$ ConnectionStrings:dbConnectionString %>">
</asp:SqlDataSource>
Also, please note that if the SelectCommand for your DataSource is handled in the codebehind, that means the DataBind will overwrite your <Columns> in the markup. To get around this, you should define the columns in the code behind before the DataBind. So say I wanted to add another ButtonField column to my forwarded page (notice the SelectCommand is not provided in the markup), I added the following before the setting the SelectCommand and doing the DataBind:
Dim id As New ButtonField()
id.ButtonType = ButtonType.Button
id.Text = "Load"
id.CommandName = "Select"
PubDetails.Columns.Add(id)
You need to declare the KeyNames of the items you are binding on your markup. For example:
<asp:GridView id="grid" runat="Server" DataSourceID="YourSQLDataSource" DataKeyNames="ID,Name" />
In your case, you seemed to be handling the OnRowDataBound event. You can do this to grab the key inside RowBound:
If e.Row.RowType = DataControlRowType.DataRow Then
Dim datakey As String = GridView1.DataKeys(e.Row.RowIndex).Value.ToString() 'get the datakey
End If
Your second question is difficult to answer because you did not specify how you want the user to be redirected, if from the client side using Javascript or from the Server side. You also did not specify how do you expect to populate the details on the Details page. Do you expect to read a parameter from the URL and use it to get the record details from the database?
How can I change my selecommand, and keep it through the remainder of the page (when using pagination, sorting)?
I have a page of checkboxes:
<input type="checkbox" name="checkbox_1" />
<input type="checkbox" name="checkbox_2" />
<input type="checkbox" name="checkbox_3" />
<asp:Button runat="server" Id="CustomButton" text="Create Report" PostBackUrl="report.aspx?"/>
Then on report.aspx I want to generate a standard listview based on the selections in the checkbox.
<asp:ListView runat="server" ID="ReportListView" DataSourceID="ReportListViewSDS">
<LayoutTemplate runat="server">
...<asp:PlaceHolder runat="server" ID="itemPlaceHolder" />...
</LayoutTemplate>
<ItemTemplate>
...
</ItemTemplate>
</asp:ListView>
I want to be able to sort and paginate that listview. This is an idea of what i want in the code behind:
Protected Sub ReportListView_PreRender(ByVal sender As Object, ByVal e As System.EventArgs)
' What's the correct way to reference the listview?
' When I use the below code i get "ReportListView is not declared...."
' ReportListView.SqlCommand = "SELECT " & checkbox1 & ", " & checkbox2 & " WHERE..."
End Sub
I'm not sure if I'm even going in the right direction with this, any help is appreciated. Will the changes i make to the sql command in the PreRender function hold when I have applied pagination or sorting to the listview?
If I understand your question correctly, you want to open a new page and use the prior page's values in the select statement for the ListView's SqlDataSource on the new page, correct?
First, a few observations:
In your first page, you appear to be intending to call the second page with a query string (PostBackUrl="report.aspx?), but you don't appear to set the query string.
Your PreRender event for the ListView control has the wrong signature. It only takes one argument, EventArgs:
Protected Sub ReportListView_PreRender(ByVal e As EventArgs)
Your ListView appears to be using a SqlDataSource as it's binding source (DataSource="ReportListViewSDS"). More about that below.
There is no SqlCommand property or method for the ListView control.
Since you're binding the ListView to a SqlDataSource, it'd be simplest to set the Select command and the parameters in the markup, like this:
<asp:SqlDataSource ID="ReportListViewSDS" runat="server"
SelectCommand="SELECT checkbox1, checkbox2, checkbox3 FROM <table> WHERE checkbox1 = #parm1 AND checkbox2 = #parm2 AND checkbox3 = #parm3">
<SelectParameters>
<asp:FormParameter FormField="checkbox_1" Name="parm1" />
<asp:FormParameter FormField="checkbox_2" Name="parm2" />
<asp:FormParameter FormField="checkbox_3" Name="parm3" />
</SelectParameters>
</asp:SqlDataSource>
Replace <table> in the SelectCommand with the name of your table. You can adjust the names of the columns you're selecting, as well as the parameters you're using, as desired. I simply used 3 checkboxes as that's what you had in the code you posted.
Also note, NO VALIDATION of the parameters will be done by the SqlDataSource, so if you want to prevent SQL Injection attacks and other security risks, you'll want to do validation in the Selecting event of the SqlDataSource.
More information can be found here:
SqlDataSource Class
FormParameter Class
Actually this was much easier than I thought. Sorry, just a newbie mistake i guess. i ended up simply doing:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim SqlCommand As String
' create the sql command using the Request.Form vars i wanted.
' ...
' Run the sql command, I can access the listview directly, just like a global variable:
ReportListView.SelectCommand = SqlCommand
ReportListView.DataBind()
End Sub
And that seemed to do it. Actually very easy.
I want to set a parameter for a SqlDataSource programmatically as described in Step 5 at http://www.asp.net/data-access/tutorials/using-parameterized-queries-with-the-sqldatasource-vb . Also a GridView is bound to the sqlDataSource. My markup is:
<asp:SqlDataSource ID="mySqlDataSource" runat="server"
ConnectionString="<%$ ConnectionStrings:ConnectionStringHTL %>"
SelectCommand="SELECT [subscription_con] FROM [HTL_CONSUME_CON] WHERE ([subscription_con] = #subscription_con)">
<SelectParameters>
<asp:Parameter Name="subscription_con" Type="Int32" />
</SelectParameters>
</asp:SqlDataSource>
<asp:GridView ID="myGridView" runat="server" AllowPaging="True"
AllowSorting="True" DataSourceID="mySqlDataSource">
</asp:GridView>
In the codebehind, I have:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
mySqlDataSource.SelectParameters("subscription_con").DefaultValue = calcResult()
End Sub
The return value from calcResult() is different for each postback. The postback occurs when the user clicks a Button on the form that has UseSubmitBehavior=True.
I've use the debugger to step through the code behind and I see it executed for each page load and I see the expected values returned from clacResult().
However the bound DataGrid is never updated on the postbacks, it only updates on the first page load.
If I change the SqlDataSource parameter to have a control as the source, then it works on postbacks. In otherwords, I changed the markup to use:
<asp:ControlParameter ControlID="myTextBox" Name="subscription_con" PropertyName="Text" Type="Int32" />
and I changed the code behind to be:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
myTextBox.Text = calcResult()
End Sub
With the TextBox control as the source of the SqlDataSource parameter, update of the GridView works for the original page load and all postbacks. However, I really have no need for the TextBox and would prefer not to use it.
What am I missing about how to set a parameter programmatically for an SqlDataSource? Why doesn't the bound GridView get updated on postbacks when setting the SqlDataSource parameter programmatically when there is no control source?
You may need an explict databaind on postbacks:
if (Page.IsPostBack)
{
grid.DataBind();
}
Should do it.
C#
SqlDataSource1.SelectParameters["Where_Clause"] = new Parameter() { Name = "Where_Clause", DefaultValue = "WHERE m.Id = 1" };
Greedy Networks.
In a detailsview, how can I prepopulate one of the textboxes on the insertcommand (When the user clicks insert and the view is insert).
I think this would work for codebehind:
Dim txtBox As TextBox = FormView1.FindControl("txtbox")
txtbox.Text = "Whatever I want"
Is this right? What do I need in the aspx (not as sure)? Also, I'm assuming the server-side code will go in the itemcommand or insertcreating event.
I have typed this in VB.NET but I am using C# (I can do both so on a language agnostic forum I might type the problem in another language). I am also using a SqlDataSource, with my parameters and insert/delete/edit commands all created.
I am trying to generate a random GUID (using the GUID object), which will be prepopulated in the textbox.
Also, is the postbackurl property of a button not another way of preserving form state?
Thanks
I would update the field in the DetailsView to a TemplateField:
<asp:TemplateField>
<InsertItemTemplate>
<asp:TextBox ID="txtField" runat="server" Text='<%# Bind("GUID") %>'/>
</InsertItemTemplate>
<ItemTemplate>
<asp:Label ID="lblField" runat="server" Text='<%# Bind("GUID") %>'/>
</ItemTemplate>
</asp:TemplateField>
Then you have two options:
generate your GUID and insert into
your datasource. This may have to be done with SQL since you mentioned using SqlDataSource
remove the binding and access the controls from code in the
DataBound event of your DetailsView
Private Sub dv_DataBound(ByVal sender As Object, ByVal e As EventArgs) Handles dv.DataBound
dim txt as Textbox = dv.FindControl("txtField")
txt.Text = GenerateGUID()
End Sub
I'm guessing you need to use one of detailsview events.
Hook up to ItemCommand, ModeChanging or ModeChanged events and fill your value there.
I am doing something like this as well. I am hiding the DetailsView and showing it when the user clicks a button.
dvDetails.ChangeMode(DetailsViewMode.Insert)
pnlDetailMenu.Visible = True
Dim ColumnTextBox As TextBox
ColumnTextBox = dvDetails.Rows(0).Cells(1).Controls(0)
If Not ColumnTextBox Is Nothing Then
ColumnTextBox.Text = "Initial Value"
End If