On my aspx page I have a gridview template that when it is rendered has 100 - 200 rows and each row has a check box.
When the page loads 5 check boxes are automatically checked. If I manually check another 3 then press the submit button, then loop through all the gridview rows to find out which rows had a checked box then it still remembers the original 5. How do I make it remember the updated 8?
Protected Sub mySubmitButton_Click(sender As Object, e As EventArgs)
Dim myArray As ArrayList = New ArrayList()
For Each myRow As GridViewRow In MyGridview.Rows
If CType(myRow.FindControl("MyCheckbox"), CheckBox).Checked Then
myArray.Add(MyGridview.DataKeys(MyRow.RowIndex).Value)
End If
Next
'add to DB myArray
End Sub
I tried this on the gridview in the asp.net and it made no difference
ViewStateMode="Disabled" and ViewStateMode="Enabled"
Thanks for the help
Is the ViewState enabled on the GridView?
Have you got the logic to load your Grid in the Page_Load event, if so add it in if(!IsPostBack)
Related
I have searched this site for what I need, but none of the answers just quite fits my needs. So here's the deal:
I am dynamically loading a usercontrol to aspx page along with some buttons like this:
Dim uc As UserControl
Dim btns As New List(Of LinkButton)
uc = LoadControl("path_to_ascx")
btns.Add(New LinkButton With {.ID = "btnid", .Text = "Sometext"})
uc.GetType().GetProperty("tblButtons").SetValue(uc, btns, Nothing)
holder2.Controls.Add(uc) 'holder2 is an id of a PlaceHolder
An this work perfectly fine. The buttons show on the page as expected. Now I am having trouble, how to tell these buttons to rise an event written in aspx page, to which a usercontrol is being loaded to.
Public Sub btnClick(sender As Object, e As EventArgs)
'do stuff
End Sub
Why I want to achieve this? Because I have a pretty complex UserControl which I want to reuse as much as possible, but buttons will do different stuff on every aspx page this UserControl will be loaded to.
Thanks
I have solved my problem. In UserControl, I added dynamic buttons to every row on OnRowCreated event.
I was loading UserControl to aspx with buttons like in my question, I just added an ID property to my usercontrol:
Dim uc As UserControl
Dim btns As New List(Of LinkButton)
uc = LoadControl("path_to_ascx")
btns.Add(New LinkButton With {.ID = "btnid", .Text = "Sometext", .CommandName = "cmdName"})
uc.ID = "UserControl1" 'here I added ID property
uc.GetType().GetProperty("tblButtons").SetValue(uc, btns, Nothing)
holder2.Controls.Add(uc) 'holder2 is an id of a PlaceHolder
And after I add an EventHanlder like this:
AddHandler TryCast(holder2.FindControl("UserControl1").FindControl("grid"), GridView).RowCommand, AddressOf grid_RowCommand
'grid is the ID of GrdiView in UserControl
And here is the event for gridview rowCommand written in aspx code behind:
Protected Sub grid_RowCommand(sender As Object, e As GridViewCommandEventArgs)
If e.CommandName = "someCmdName" Then
'do stuff
Else
'do somthing else
End If
End Sub
Maybe my question was not good enough, because I did not mention, that I will be loading buttons to gridview row on rowCreated event and hook them up to RowCommand for wich I apologise.
If someone knows another way to do this, it would be much appreciated to share.
Regards
I am trying to retrieve data when selecting a row in gridview using asp.net.
I have gridview inside ModalPopUp dialog that pop-ups whenever the user clicks the button "Browse". The gridview was populated by data from database. The first column was a Button field named "Select", so everytime the user clicks the button from specific row the data on the first index must be displayed inside a textbox, and the ModalPopUp dialog must be closed.
I tried below codes on retrieving the data from selected row and closing or hiding the ModalPopUp dialog after clicking button field inside gridview but it doesn't work.
Protected Sub GridView1_RowCommand(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewCommandEventArgs) Handles GridView1.RowCommand
If e.CommandName = "Select" Then
Dim row As GridViewRow = GridView1.SelectedRow
txttitle.Text = row.Cells(1).Text
mdlpopup.Hide()
End If
End Sub
Thanks in advance.
Modify your code as like,
txttitle.Text = DirectCast(row.Cells(1).FindControl("TxtboxID"),TextBox).Text
The datagrid reads from several xml files, so I create the columns dynamically, and added a templatefield as the last column.
A link button is added in the templatefield using RowDataBound.
Private Sub GridItem_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles GridItem.RowDataBound
Try
If e.Row.RowType = DataControlRowType.DataRow Then
Dim linkb As New LinkButton
linkb.Text = "Delete"
linkb.ID = "LinkDeleteItem"
linkb.OnClientClick = "javascript:DeleteItem('" & Convert.ToString(e.Row.RowIndex) & "')"
e.Row.Cells(GridItem.Columns.Count - 1).Controls.Add(linkb)
End If
Catch ex As Exception
lblMessage.Text = ex.Message
End Try
End Sub
Everything works fine.
But when I click a button outside the gridview, to open a window to add a new item to the grid, the linkbuttons disappear. But the column is still there.
If I just close the new window without saving a new data (which will prompt the grid to rebind), the column remains empty. I had to reload the gridview for the linkbuttons to appear.
Is it because the linkbuttons are created on rowdatabound? How should I solve this?
This is happening because the OnRowDataBound event of GridView is NOT called on next postback. This happens because by default viewstate of GridView is set true i.e. EnableViewState property of Gridview is true. When ViewState is on, Gridview stores data from the same and OnRowDataBound event is not called. Also, at this point View state will not be applied for your linkButtons as they aren't created in page_load.
Try setting EnableViewState property to false for your gridview:
<asp:GridView ID="CustomersGridView"
OnRowDataBound="CustomersGridView_RowDataBound"
EnableViewState="false"
.... />
OR you can also bind your GridView in page_Load as:
protected void Page_Load(object sender, EventArgs e)
{
CustomersGrIdView.DataBind();
}
Now after every postback your OnRowDataBound event will be called and hence the LinkButtons will be available everytime.
NOTE: Setting EnableViewState property to false for gridview can be a bad practice to an extent, especially in scenarios of heavy data usages. Same goes for Binding gridview every time.
When using dynamic controls, they exist only until the next postback.ASP.NET will not re-create a dynamically added control. If you need to re-create a control next time too on postback, you should perform the control creation in the PageLoad event handler.
This will give you benefit of using view state with your dynamic control. Even though view state is normally restored before the Page.Load event, if you create a control in the handler for the PageLoad event, ASP.NET will apply any view state information that it has after the PageLoad event handler ends.
I'm trying to add a set of LinkButtons to the PagerRow of a GridView in an UpdatePanel. I'm using the RowCreated event to instantiate and add these. The problem I have is the click handlers are only fired the second time.
I create the LinkButtons using
Protected Sub grd_RowCreated(ByVal sender As Object, ByVal e As GridViewRowEventArgs)
If (e.Row.RowType = DataControlRowType.Pager) Then
Dim pageSizer = New GridViewPageSizer(grdItems)
e.Row.Cells(0).Controls.AddAt(0, pageSizer)
End If
End Sub
To create the LinkButtons themselves, I'm using
Dim lnkSize = New LinkButton() With { _,
.Text = size.ToString(), _
.CommandArgument = size.ToString(), _
.ID = "pageSizer" & size
}
AddHandler lnkSize.Click, AddressOf lnkPageSize_Click ' an EventHandler which just changes pagesize based on CommandArgument
liSize.Controls.Add(lnkSize)
The GridViewPageSizer inherits HtmlGenericControl and adds an event handler for the click of each button. On every postback, the pager row is recreated, so the old buttons are replaced with a new set and their event handlers only fire on the second click. If I check for !IsPostBack, the buttons disappear after the first click. I've tried rebinding the grid after the buttons are clicked and the pagesize changes but the same thing happens. Is there a way around this?
In order for an EventHandler to trigger correctly, you need to bind it on Page Init/PreInit.
Make a session indicator and on postback, check that session on Page Init.
If that satisfies the condition, instead of recreating it on RowCreated Event, recreate the controls together with the Events on Page Init instead.
This time, events will trigger correctly.
I have a navigation bar which is dynamically populated with LinkButtons by an ASP repeaterControl.
I have no problem accessing, and setting properties for the clicked LinkButton. This I can do using the sender object from the fired LinkButton. Once a LinkButton is clicked, it is highlighted in bold.
My problem is to clear the bold property of the previously clicked linkButton when a new LinkButton ( another RepeaterItem within the same repeater) is clicked.
Any ideas on this, please? Many thanks!
ps.
I cannot access the buttons through their ID, since they all have the same ID within the repeater.
I have unique arguments on each RepeaterItem (CommandArgument), but when I try to iterate through all linkbuttons, only static linkbuttons are found, none inside the repeater. See below:
Dim c As Control
For Each c In Form1.Controls
If TypeOf c Is LinkButton Then
MsgBox(DirectCast(c, LinkButton).CommandArgument)
End If
Next c
Try this:
For each item as RepeaterItem in YourRepeaterControl.Items
Dim button as LinkButton = item.FindControl("YourLinkButtonId")
If button IsNot Nothing Then
'Do whatever you want here
End If
Next