I have the following DetailsView, with several BoundFields, and SQlDataSource that populates the fields:
<asp:DetailsView ID="DetailsView1" runat="server" AutoGenerateRows="False" DataKeyNames="TICKET_ID"
DataSourceID="SqlDataSource1" HeaderText="Completed IT ticket information"
CellPadding="4" ForeColor="#333333" GridLines="None" HorizontalAlign="Center">
<Fields>
<asp:BoundField DataField="TICKET_ID" SortExpression="TICKET_ID" Visible="False" />
<asp:BoundField DataField="SUBMITTED_BY" SortExpression="SUBMITTED_BY" Visible="False" />
<asp:BoundField DataField="TICKET_TITLE" HeaderText="Ticket Description" SortExpression="TICKET_TITLE" />
<asp:BoundField DataField="SUBMITTED_BY" HeaderText="Submitted By" SortExpression="SUBMITTED_BY" />
<asp:BoundField DataField="SOLUTION_NOTES" HeaderText="Solution Notes" SortExpression="SOLUTION_NOTES" />
<asp:BoundField DataField="EMAIL_HISTORY" HeaderText="Email History" SortExpression="EMAIL_HISTORY" />
<asp:BoundField DataField="COMPLETED_BY" HeaderText="Completed By" SortExpression="COMPLETED_BY" />
<asp:BoundField DataField="COMPLETE_DATE" HeaderText="Completed Date" ReadOnly="True" SortExpression="COMPLETE_DATE" />
</Fields>
</asp:DetailsView>
</div>
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:TTPRODConnectionString %>"
SelectCommand="SELECT USR_ITFAC.TS_ID AS TICKET_ID, USR_ITFAC.TS_EC1_SUBMITTER AS SUBMITTED_BY, USR_ITFAC.TS_TITLE AS TICKET_TITLE, USR_ITFAC.TS_SOLUTION_NOTES AS SOLUTION_NOTES, USR_ITFAC.TS_EMAIL_HISTORY AS EMAIL_HISTORY, TS_USERS.TS_NAME AS COMPLETED_BY, DATEADD(HOUR,-8,USR_ITFAC.TS_CLOSEDATE) AS COMPLETE_DATE FROM USR_ITFAC INNER JOIN TS_USERS ON USR_ITFAC.TS_COMPLETED_BY = TS_USERS.TS_ID WHERE (USR_ITFAC.TS_ISSUEID = '00033')">
<SelectParameters>
<asp:QueryStringParameter Name="ts_id" QueryStringField="id" />
</SelectParameters>
</asp:SqlDataSource>
I hard-coded a value at the end of the query '00033', which is the ID of a record I know is in the database. I tested the query and it returns a value as expected, what I'm trying to do is fetch the values of the BoundField in the code-behind after a user has pressed a button.
Protected Sub btnSubmit_Click(ByVal sender As Object, ByVal e As System.EventArgs)
Try
''Use a Dictionary to store answers to questions that were marked poor or fair
Dim answers As New Dictionary(Of String, String)
''For Each test
For Each dv_row As DetailsViewRow In DetailsView1.Rows
''Print rows data to console
Next
Catch ex As Exception
lblWarn.Text = "<br /><b>Please answer all the questions on this survey</b><br />"
'Response.Write(ex)
End Try
End Sub
Above I'm doing a test to fetch the values and print them onscreen, the problem is that the row count is 0, I'm not sure why that is. I expected the row count to be 8, when debugging I notice that the field count is 8, but I'm not sure how to get the values from the fields. I thought the way to get row data was something like:
Dim rowText As String = DetailsView1.Rows(0).Cells(1).Text
But when I try that I get a Null exception. Any insight is appreciated.
I misread the code. FindControl() is effective when using templates.
Try instead to use the FindControl(controlID) method on your details view to find your data-bound control. The method returns an object of type Control, so you'll probably have to type cast the result to get any real use out of it.
Was able to get it up and running. Turns out the BoundFields were not getting populated because the parameter in the QueryStringField, namely "id", was not being specified in the request URL. To resolve this I first tried to rewrite the URL path on Page_Load, that didn't work, so I just created a separate page with a hyperlink to the page I'm working on with a variable appended to the end of the URL which provides the QueryString for the SQLDataSource to reference. More on the QueryString property here.
Related
Hi me again with another question.
I'm using VS2019 and VB on an aspx page. I have a gridview that has Edit enabled.
enter image description here
When a user clicks the EDIT link Progress % and Comments become editable.
What I want to do is make the Goal be editable if Approved is set to No.
How can I do this?
<asp:GridView ID="grdgoals" runat="server" AutoGenerateColumns="False" DataSourceID="DS1" Height="225px" Width="1001px" BorderColor="#003960" BorderStyle="Solid" BorderWidth="1px" DataKeyNames="goalid" EmptyDataText="No goals found." Font-Bold="True" Font-Names="Calibri" Font-Overline="False" Font-Size="Medium" Font-Strikeout="False" ForeColor="#00AD86" ShowHeaderWhenEmpty="True" AllowSorting="True" style="margin-right: 21px">
<Columns>
<asp:BoundField DataField="goalid" HeaderText="goalid" ReadOnly="True" SortExpression="goalid" Visible="False" />
<asp:CommandField EditText="EDIT" ShowEditButton="True" ShowHeader="True">
<HeaderStyle BorderColor="#003960" />
<ItemStyle Font-Names="Calibri" Font-Underline="True" ForeColor="#006EAA" HorizontalAlign="Center" BorderColor="#003960" Width="20px" />
</asp:CommandField>
<asp:BoundField DataField="goaltext" HeaderText="Goal" SortExpression="goaltext" ReadOnly="True" >
<HeaderStyle BorderColor="#003960" />
<ItemStyle BorderColor="#003960" Width="250px" />
</asp:BoundField>
<asp:BoundField ConvertEmptyStringToNull="True" DataField="type" HeaderText="Type" ReadOnly="True" >
<ItemStyle Width="70px" />
</asp:BoundField>
<asp:BoundField DataField="progress" HeaderText="Progress %" SortExpression="progress" >
<HeaderStyle BorderColor="#003960" />
<ItemStyle HorizontalAlign="Center" BorderColor="#003960" VerticalAlign="Middle" Width="20px" />
</asp:BoundField>
<asp:BoundField DataField="comments" HeaderText="Comments" SortExpression="comments" ItemStyle-Wrap="true">
<ControlStyle Height="400px" Width="240px" />
<HeaderStyle BorderColor="#003960" />
<ItemStyle BorderColor="#003960" Width="250px" HorizontalAlign="Left" VerticalAlign="Middle" />
</asp:BoundField>
<asp:BoundField DataField="approved" HeaderText="Approved" ReadOnly="True" SortExpression="approved" >
<ItemStyle HorizontalAlign="Center" Width="40px" />
</asp:BoundField>
</Columns>
<EditRowStyle HorizontalAlign="Left" VerticalAlign="Top" />
<HeaderStyle ForeColor="#006EAA" />
</asp:GridView>
I have searched online looking for answer but haven't found anything.
Ok, so how much extra code is it to simple drop in a "plain jane" button to click on and edit?
It not much!!!
You do have to bear the cost/time of building a form layout for the one row, but at the end of the day:
this tends to be "easy" for the users.
You can also then move the row delete button to that "form layout" area for editing one record. (this means you don't need a delete record button on the GV - not a huge deal, but that means users have to make a "bit more" effort to delete a row of data if that option is desired).
However, the "why" of having a detail edit layout?
You can now have MUCH more control over your logic (such as the rule to allow what to edit, change or even "enable" based on other values. And such code is clean easy server side code.
And this allows far more code logic into the editing of that data. (required fields, formatting, all that stuff.
Best bonus feature?
Such a approach now ALSO allows adding of new records in a MUCH more user friendly way, since now the "edit" area you build ALSO can be used as the "add new" record area. (so, you save having to write separate code for edit and adding - the one solution does both). And this also means the end user has the "same" experience when editing existing, or adding new - it shortens the user learning curve.
Now, about the only downside?
Well, when starting out, those wizards can be a real gift horse. And I still after all these years often use the wizard(s) to create the GV.
however, I THEN clean it up a bit, and remove things from the page.
(such as removing the datasource on the page).
And the other tip?
If possbile, build a few "helper" routines. They can be used over and over.
For example, I became VERY tired of having to type in code with a row of data, and then "please fill out" those controls on the page with that data.
Then after done, we have to take that those controls, and send back to the database. We do this "over and over". And the code to do this is darn near the "same" over and over. So, then, why not write one sub routine that can do this for ANY page we work on!!!
So, here is a working approach.
for the GV, then the markup becomes rather clean - just some fields.
Say, like this markup:
<asp:GridView ID="GridView1" runat="server" Width="40%"
AutoGenerateColumns="False" DataKeyNames="ID"
CssClass="table table-hover table-striped" >
<Columns>
<asp:BoundField DataField="FirstName" HeaderText="FirstName" />
<asp:BoundField DataField="LastName" HeaderText="LastName" />
<asp:BoundField DataField="HotelName" HeaderText="HotelName" />
<asp:BoundField DataField="City" HeaderText="City" />
<asp:BoundField DataField="Description" HeaderText="Description" />
<asp:TemplateField>
<ItemTemplate>
<asp:Button ID="cmdEdit" runat="server" Text="Edit"
CssClass="btn myshadow"
OnClick="cmdEdit_Click"
/>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
Note a few things in above:
If we don't use width, or use 100%? The GV will expand to the WHOLE page - it is what we call "responsive".
I assume that you have bootstrap installed, and most projects do (by default).
The result is a "very" nice grid, and the fonts + spacing and layout is "tweaked" by bootstrap. The result is quite nice.
Code to load the GV is this:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not IsPostBack Then
LoadData()
End If
End Sub
Sub LoadData()
Dim strSQL = "SELECT * FROM tblHotelsA ORDER BY HotelName"
Dim cmdSQL As New SqlCommand(strSQL)
GridView1.DataSource = MyrstP(cmdSQL)
GridView1.DataBind()
End Sub
Note the "helper" routine MyrstP. I use this "over and over" everywhere.
(I'll post that at end of this post).
So, I removed the Sqldatasourc1 from the page. I find that you obtain/enjoy MUCH more control over the code. (but, if you don't have a helper routine, then setting up a query + connection and all that jazz? Then you might as well just stick with the wizard generated SqlDataSource on the page. But, you find over time that using code behind is a "less effort" choice, and one that gives you far more control (say to filter, or do other things).
And note the table hover (you get a "nice" row hover effect), and note the table-striped. That gives you a nice alternating row shade - and you do not need a messy "alternating" template.
So far? We have a VERY clean markup, and so far VERY little code has been written.
Now, not the button we dropped into the GV. That is a plan jane asp.net button. We don't need to use "speical" commands, "speical" code or anything. Just a good old fashioned button and button click.
However, do note that we have a click event for the button. Normally, I often just double click on a button, and then a code behind stub is created, and we are jumped to the code behind editor.
however, since the button is "nested" in a GV, then we can't double click on that button to create a event.
So, flip to markup. And in markup type in
OnClick=
WHEN you hit the "=", then intel-sense should pop up and gives you the option to create the event. (since we can't use double click on button to do this).
So, it looks like this:
And thus the code is for button click:
Protected Sub cmdEdit_Click(sender As Object, e As EventArgs)
Dim btn As Button = sender
Dim gRow As GridViewRow = btn.NamingContainer
Dim intPK As Integer = GridView1.DataKeys(gRow.RowIndex).Item("ID")
Dim cmdSQL = New SqlCommand("SELECT * FROM tblHotelsA WHERE ID = #ID")
cmdSQL.Parameters.Add("#ID", SqlDbType.Int).Value = intPK
Dim rstHotel As DataTable = MyrstP(cmdSQL)
ViewState("PKID") = intPK
fLoader(EditRecord, rstHotel.Rows(0))
GridView1.Visible = False ' Hide GV
EditRecord.Visible = True ' show edit area
End Sub
Again, note the small amount of code.
The button click thus:
we get GV row
we get GV row PK database ID (using datakeys feature)
we pull that data row into data table
we call the floader() routine that takes ONE row, fills out controls.
the resulting effect is thus this:
And our helper MyRstP routine is this:
Public Function MyrstP(cmdSQL As SqlCommand,
Optional cmdOnly As Boolean = False) As DataTable
Dim rstData As New DataTable
Using mycon As New SqlConnection(GetConstr)
Using (cmdSQL)
cmdSQL.Connection = mycon
mycon.Open()
If cmdOnly Then
cmdSQL.ExecuteNonQuery()
Else
rstData.Load(cmdSQL.ExecuteReader)
End If
End Using
End Using
Return rstData
End Function
I'll post more code from above (later this evening)., and say have some "conditional" code. Say if the hotel not active, we can't edit description.
I have a datepicker calendar in JS. Once a user clicks on a date, that date gets passed to the asp:TextBox as string. I would like to query my database with the text in textbox without having to click on a button. Is this possible?
Well, there is what, 100's of JS date pickers?
(which one you using might have helped here).
So, it going to depend on how the JS works.
Lets drop in a text box, set autopostback = true, and then add a text change event.
So, we have this markup:
<h2>Choose Date</h2>
<asp:TextBox ID="txtDate" runat="server"
TextMode="Date" AutoPostBack="True" ></asp:TextBox>
and the code behind is this:
Protected Sub txtDate_TextChanged(sender As Object, e As EventArgs) Handles txtDate.TextChanged
Debug.Print("Date changed to " & txtDate.Text)
End Sub
Now run the page and we have this:
Note how that text box already shows a date picker if you set textMode = date. Maybe you don't need a JS date picker then?
Ok, so lets select a date:
And because I have autopost-back = true, I see this in output:
Output:
So, in your server side text changed event - it should trigger. But that triggering of the text changed event may well depend on how and what kind of out of the 1000+ date picker JS examples I can find on the web that you are using here.
So now lets query the database based on that value then right?
So, say we have this markup:
<h2>Choose Date</h2>
<asp:TextBox ID="txtDate" runat="server" TextMode="Date" AutoPostBack="True" ></asp:TextBox>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
DataKeyNames="ID" CssClass="table">
<Columns>
<asp:BoundField DataField="FirstName" HeaderText="FirstName" />
<asp:BoundField DataField="LastName" HeaderText="LastName" />
<asp:BoundField DataField="HotelName" HeaderText="HotelName" />
<asp:BoundField DataField="VisitDate" HeaderText="Vist" DataFormatString="{0:yyyy-MM-dd}" />
<asp:BoundField DataField="Description" HeaderText="Description" />
</Columns>
</asp:GridView>
We select a date, and show visits for that date.
Our code thus becomes this:
Protected Sub txtDate_TextChanged(sender As Object, e As EventArgs) Handles txtDate.TextChanged
Debug.Print("Date changed to " & txtDate.Text)
Using conn As New SqlConnection(My.Settings.TEST4)
Dim strSQL =
"SELECT * from tblHotels WHERE VisitDate = #VisitDate ORDER BY HotelName"
Using cmdSQL = New SqlCommand(strSQL, conn)
cmdSQL.Parameters.Add("#VisitDate", SqlDbType.DateTime).Value = txtDate.Text
conn.Open()
GridView1.DataSource = cmdSQL.ExecuteReader
GridView1.DataBind()
End Using
End Using
End Sub
And we now have this:
I'm trying to use Session to record the data of the 1st column of current row to be used in another Web From which will be opened using a LinkButton that is in the GridView.
Basically, if I click the LinkButton on the 1st row, the 1st column data of the 1st row will be copied to the next Web Form. But before I do that, I want to do a smaller scale experiment to test it. So instead for now I want the Session to copy the data into a TextBox in the same form.
For reference, here is the design of the GridView, most rows removed since they're not relevant:
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
BorderColor="Black" BorderStyle="Solid" BorderWidth="1px" Font-Names="Arial">
<AlternatingRowStyle BackColor="#B7DBFF" />
<Columns>
<asp:BoundField DataField="caseticket" HeaderText="Ticket #" >
<HeaderStyle BackColor="#000066" ForeColor="White" Wrap="False" width="10%"/>
<ItemStyle Wrap="False" />
</asp:BoundField>
<asp:TemplateField ShowHeader="False">
<HeaderStyle BackColor="#000066" ForeColor="White" Wrap="False" width="10%"/>
<ItemTemplate>
<asp:linkbutton ID="newLog" runat="server" onclick = "CaseLog_click" >Add Log </asp:linkbutton>
</ItemTemplate>
</asp:TemplateField>
</Columns>
<HeaderStyle BackColor="#000066" />
<RowStyle HorizontalAlign="Center" />
</asp:GridView>
For the TemplateField is a LinkButton with a onclick property. With it, I created the sub:
Sub CaseLog_click(ByVal sender As Object, ByVal e As EventArgs)
Session("ticket") = GridView1.SelectedRow.Cells(1).Text
'Response.Redirect("~/CaseLog.aspx") ==> will be using this to proceed to next Web Form
TextBox1.Text = Session("ticket") '==> For test use only.
End Sub
If I only kept the Response.Redirect("~/CaseLog.aspx") in the sub, the LinkButton can direct me to the next Web Form. But as it is now, during testing when I use the LinkButton I get an error on the session line of the sub.
Object reference not set to an instance of an object.
Is the code salvageable, or do I need to redo this?
Thanks.
It looks like the button event to select the row is not wired up.
I would use say this:
<asp:BoundField DataField="HotelName" HeaderText="HotelName" SortExpression="HotelName" />
<asp:ButtonField CommandName="Select" HeaderText="Select" ShowHeader="True" Text="Button" />
Note CAREFULL how we put the CommandName="Select" in above. If you don't do this, then the selected row does not come though correctly to the click event you have.
You could try the select command as per above on your link button, but I would just use the above. Now, hightlight the grid in the form desinger. On the properity sheet, go to events, and double click on the SelectedIndex Change event. So, your buttion is not changing the selected index correctly.
The code stub will look like this:
Protected Sub GridView1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles GridView1.SelectedIndexChanged
Dim lgridrow As GridViewRow = Me.GridView1.SelectedRow
Debug.Print("<" & lgridrow.Cells(0).Text & ">")
Debug.Print("<" & lgridrow.Cells(3).Text & ">")
Debug.Print("<" & Me.GridView1.SelectedRow.Cells(3).Text & ">")
End Sub
Note VERY careful how the event code stub is setup - the event args are different then yours.
So, you can try the CommandName="Select" in your existing code, but if not, then try the above button field as opposed to your custom asp.net button you have. As it stands, it don't look like your asp.net button is firing the row-changed event.
Edit and follow up:
Can I have extra buttons - run their own code?
Yes, you can. You can do this several ways (one is to pick up which button was clicked in the SelectedIndex change event.
Or, you can drop in extra buttons and use that event code stub.
So, in my example, lets add an extra button.
we now have this:
<Columns>
<asp:BoundField DataField="ID" HeaderText="ID" InsertVisible="False" ReadOnly="True" SortExpression="ID" />
<asp:BoundField DataField="LastName" HeaderText="LastName" SortExpression="LastName" />
<asp:BoundField DataField="FirstName" HeaderText="FirstName" SortExpression="FirstName" />
<asp:BoundField DataField="HotelName" HeaderText="HotelName" SortExpression="HotelName" />
<asp:ButtonField CommandName="Select" HeaderText="Select" ShowHeader="True" Text="Button" />
<asp:TemplateField>
<ItemTemplate>
<asp:LinkButton ID="LinkButton1" runat="server" OnClick="LinkButton1_Click"
CommandName="MySelect" CommandArgument ="<%# Container.DisplayIndex %>"
style="background-color:gray;color:white;text-decoration:none;padding-left:6px;padding-right:6px"
text="Mybutton"></asp:LinkButton>
</ItemTemplate>
</asp:TemplateField>
</Columns>
We thus have this:
Now, we can attach/have button code for the extra button. But NOTE careful we did NOT use the built in SELECT for the command argument. The REASON is that if we have Command=select, then the selected index WILL fire, but AFTER our button code stub. That means we cannot use the selectedrow (too early).
So, what we do/did in above was have the CommandArguemnt PASS the selected row value - that value will pass ok, and thus we don't care that the selected index event does not fire (and by CHANGING our command argument to NOT "select", then in fact the selectedindexchange event DOES NOT fire.
As a result, we use the passed row in the command argument, and we have this for the button code:
Protected Sub LinkButton1_Click(sender As Object, e As EventArgs)
Dim ixrow As Integer = sender.CommandArgument
Debug.Print(Me.GridView1.Rows(ixrow).Cells(0).Text)
End Sub
And note while we are editing the markup, intel-sense will give a list of options when editing. Eg this:
So, that gives us a chance to wire up (add) a standard click event). No selected index code stub is required (since the button would fire before selected index anyway). So we are now manually wiring up this event. We are NOT thus using the selectedindex change event - we don't even need it.
So, now in our button stub, we are free to do anything we want - including jumping to another page
eg:
Protected Sub LinkButton1_Click(sender As Object, e As EventArgs)
Dim ixrow As Integer = sender.CommandArgument
Debug.Print(Me.GridView1.Rows(ixrow).Cells(0).Text)
Session("HotelName") = Me.GridView1.Rows(ixrow).Cells(3)
Response.Redirect("~/ShowHotelDetails.aspx")
End Sub
So, to add separate code buttons:
Don't use selected index change event - you MIGHT still want it to run but it will run/fire AFTER your button code (so can't use selectedrow - too early).
But, you do need Command="myjunk" because without a command, then the command argument does not work. By passing the row index in commandargument, then we are free to grab data from the gridview as per above code via row index.
So, you can well dump the selected index change event. You just have to pass the row index, and work from that. The code stub can thus walk the dog, setup values in session, or even pass/make the url with parameters.
I've googled this topic as much as i could, ive found similar topics around and even on stackoverflow but none were able to resolve my issue. I have a nested gridview bound to a sqldatasource that populates a few fields as well as a checkbox field from a 'bits' field in the database. The checkboxes populate correctly from the database (checked vs. unchecked) but my 'OnCheckedChanged' event only fires when i check a checkbox but does NOT fire when it is unchecked, the page just goes through its post back. I have 'EnableViewState' set to true on the master page, local page, and on the control as well as auto post back. What i need to do is update the DB with the new value of the checkbox (checked vs unchecked) and reload. Please let me know if anyone has suggestions.
Protected Sub Gridview3_OnCheckedChanged(Sender As Object, e As EventArgs)
Dim checkbox As CheckBox = TryCast(Sender, CheckBox)
Dim gridview3 As GridView = checkbox.Parent.Parent.Parent.Parent
Dim row As GridViewRow = checkbox.Parent.Parent
sql_insert(String.Format("UPDATE [STOREIT2-PORTAL].dbo.AA5VOLUMES SET PROTECTED = '{0}' WHERE GUID = '{1}' AND AGENTID = '{2}'", checkbox.Checked, gridview3.DataKeys(row.RowIndex).Values("GUID").ToString, gridview3.DataKeys(row.RowIndex).Values("AgentID").ToString))
End Sub
<asp:GridView ID="Gridview3" EnableViewState="true" runat="server" AutoGenerateColumns="False" DataKeyNames="AgentID,GUID" OnRowDataBound="GridView3_OnRowDataBound" RowStyle-CssClass ="row" AlternatingRowStyle-CssClass="altrow" RowStyle-HorizontalAlign="Center" CssClass="gvmain"> <AlternatingRowStyle CssClass="altrow"></AlternatingRowStyle>
<columns>
<asp:BoundField DataField="AgentID" HeaderText="AgentID" SortExpression="AgentID" visible="false"/>
<asp:BoundField DataField="GUID" HeaderText="GUID" SortExpression="GUID" visible="false"/>
<asp:BoundField DataField="VolumeName" HeaderText="VolumeName" SortExpression="VolumeName" readonly="true"/>
<asp:BoundField DataField="Label" HeaderText="Label" SortExpression="Label" nulldisplaytext="<i>{No Label}</i>" readonly="true"/>
<asp:BoundField DataField="BaseCount" HeaderText="BaseCount" SortExpression="BaseCount" nulldisplaytext="<i>{No Base Images}</i>" readonly="true"/>
<asp:BoundField DataField="TimeStamp" HeaderText="TimeStamp" SortExpression="TimeStamp" nulldisplaytext="<i>{Volume has no recent snapshots}</i>" readonly="true"/>
<asp:TemplateField headertext="Protected">
<ItemTemplate>
<asp:CheckBox ID="Protected" EnableViewState="true" runat="server" autopostback="true" checked='<%# Eval("Protected")%>' OnCheckedChanged="Gridview3_OnCheckedChanged"/>
</ItemTemplate>
</asp:TemplateField>
</columns>
</asp:GridView>
I'm noticing your code does not have the 'Handles Clause' Maybe this is causing the problem you mention. . .
Handles CheckBox1.CheckedChanged
I'm having some trouble getting the results of the drop-downs in a gridview, and haven't found any helpful articles for VB code.
What I'm trying to do is build a site for tests. So far I have the gridview built w/the extra column for a drop-down list where the true/false answer will be selected. When the test is completed, there is a submit button. All is well except I need to be able to get the results of each drop-down list on post-back to a variable or array (each test contains 10 questions) so the results can be checked/graded. When the results are determined I would like to display a label in it's place and change the text value accordingly (correct or incorrect), so I'll need to be able to enumerate these as well (i.e. label1.text="Correct!", label2.text="Incorrect!", etc...).
Code so far.
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
DataSourceID="SqlDataSource1" BackColor="White" BorderColor="#3366CC"
BorderStyle="None" BorderWidth="1px" CellPadding="1">
<RowStyle BackColor="White" ForeColor="#003399" />
<Columns>
<asp:BoundField DataField="Question" HeaderText="Question"
SortExpression="Question" />
<asp:TemplateField HeaderText="Answer">
<ItemTemplate>
<% If Not IsPostBack Then%>
<asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="SqlAnswer"
DataTextField="torf" DataValueField="torf">
</asp:DropDownList>
<%Else%>
<asp:Label ID="Label1" runat="server" Text=""></asp:Label>
<%End If%>
</ItemTemplate>
</asp:TemplateField>
</Columns>
<FooterStyle BackColor="#99CCCC" ForeColor="#003399" />
<PagerStyle BackColor="#99CCCC" ForeColor="#003399" HorizontalAlign="Left" />
<SelectedRowStyle BackColor="#009999" Font-Bold="True" ForeColor="#CCFF99" />
<HeaderStyle BackColor="#003399" Font-Bold="True" ForeColor="#CCCCFF" />
</asp:GridView>
The preceding code loads 10 rows, 2 columns (column1:Question | column2-[DropDownLists]:Answer). I'm a freshman when it comes to development, so if you need additional info let me know.
Here is how I handled it:
created a page level private variable to hold our list of correct/incorrect values
Private Answers as New List(Of Boolean) 'creates a strongly typed list of t/f values
in Page.Load
if IsPostBack then
'iterate through each row
for each gridRow As GridViewRow in GridView1.Rows
'get the selected value for this answer
Dim answer as string = CType(gridRow.FindControl("DropDownList1"),DropDownList).SelectedValue
'add this answer to the list
Answers.Add(IsCorrectAnswer(answer))
next
end if
the IsCorrectAnswer function determines whether or not the answer given for this question is correct and returns a Boolean value. You would need to write this function to suit your needs.
in Button1.Click handler
'rowCounter will act as an index to the answers
Dim rowCounter as Integer = 0
For Each gridRow as GridViewRow in GridView1.Rows
'grid_RowDataBound handles the binding of single row
grid_RowDataBound(gridRow, rowCounter)
rowCounter+=1
Next
finally
Private Sub grid_RowDataBound(gridRow as GridViewRow, rowCounter as Integer)
'make the dropdown invisible
CType(gridRow.FindControl("DropDownList1"),DropDownList).Visible = False
'because we'll be acting on two properties of the label, I shove it in a variable first for ease of access
Dim label As Label = CType(gridRow.FindControl("Label1"),Label)
'set the label to visible
label.Visible = True
'set the text
label.Text = Iif(Answers(rowCounter),"Correct", "Incorrect")
End Sub
Someone probably has a cleaner solution than this, but I do know this works, at least as far as I understand the issue you are facing.
Good luck
What about binding the Visible attribute to Page.IsPostBack (note this is in C# since I'm not familiar with the syntax for VB.NET... I'm sure something similar would work):
<ItemTemplate>
<asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="SqlAnswer"
DataTextField="torf" DataValueField="torf" Visible='<%# !Page.IsPostBack %/>></asp:DropDownList>
<asp:Label ID="Label1" runat="server" Text="" Visible='<%# Page.IsPostBack %/></asp:Label>
</ItemTemplate>
check the RowDataBound event of the gridview object. It takes two parameters:
(byval sender as Object, byval e as GridViewRowEventArgs). With it, you can set the value of the label in each row to 'Correct' or 'Incorrect' on the postback.
see the example at
http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.gridview.rowdatabound.aspx
for more information
as for getting the answers into a variable, here are a couple of options
1) check viewstate. It has some overhead, so be cautious with it.
2) save the data to a Session object