I'm facing a problem with two Datapagers associated with a Listview. This is my page:
<asp:DataPager ID="PagerTop" runat="server" PagedControlID="pp" QueryStringField="page" PageSize="30"></asp:DataPager>
<asp:ListView ID="pp" runat="server" ItemPlaceholderID="holder" EnableViewState="true" OnPagePropertiesChanging="PagePropertiesChanging">
...
</asp:ListView>
<asp:DataPager ID="PagerBottom" runat="server" PagedControlID="pp" QueryStringField="page" PageSize="30"></asp:DataPager>
and the code behind is as follows
Private Sub Page_PreRender(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreRender
Dim MyData As List(Of Product)
MyData = ResultsManager.GetResults()
pp.DataSource = MyData
pp.DataBind()
End Sub
Private Sub PagePropertiesChanging(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.PagePropertiesChangingEventArgs)
PagerTop.SetPageProperties(e.StartRowIndex, e.MaximumRows, False)
PagerBottom.SetPageProperties(e.StartRowIndex, e.MaximumRows, False)
pp.DataBind()
End Sub
When I change the page, the listview is updated and shows the results corresponding with the indicated page, and PagerTop shows the selected page. That's how they are supposed to work. But PagerBottom is stucked on page 1 and never changes!
It doesn't matter which pager I click, PagerTop always works and PagerBottom always stays at page 1.
I'm running out of brilliant ideas... what can be wrong here?
a very good example is given here
http://www.c-sharpcorner.com/uploadfile/nipuntomar/datapager-in-Asp-Net-3-5/
just place another data pager with different id without any change. i have tried and worked fine for me.
Related
Forgive me as this is my first post and I am far from being IT savvy but I have been working on a project for my new job...
I am using Visual Studio 2017 and a asp.net Web form template.
I have several panels that I have set visibility to false and have set each panel to become only visible if a certain option is selected from a checkbox list.
I have managed to successfully code the visibility HOWEVER I want to allow the user to view more than one panel when more than one item is selected from the checkbox list... unfortunately it looks as though only one panel becomes visible at a time. I am assuming that they are overlapping .
I have tried putting each panel in a table to act as sort of a placeholder but with no success.
Any advice would be much appreciated 🙏
aspx.vb
Protected Sub ListBox1_Changed(ByVal sender As Object, ByVal e As EventArgs) Handles ListBox1.SelectedIndexChanged
If ListBox1.SelectedValue = "AA" Then
Panel1.Visible = True
Else
Panel1.Visible = False
If ListBox1.SelectedValue = "BB" Or ListBoxLivewell.SelectedValue = "CC" Or ListBoxLivewell.SelectedValue = "DD" Then
Panel2.Visible = True
Else
Panel2.Visible = False
End If
I suggest you create blank test page, and try this:
Markup:
<asp:CheckBox ID="CheckBox1" runat="server" Text="Panel1" AutoPostBack="true" />
<asp:CheckBox ID="CheckBox2" runat="server" Text="Panel2" AutoPostBack="true" />
<asp:CheckBox ID="CheckBox3" runat="server" Text="Panel3" AutoPostBack="true" />
<asp:Panel ID="Panel1" runat="server">
<h2>Panel 1</h2>
</asp:Panel>
<asp:Panel ID="Panel2" runat="server">
<h2>Panel 2</h2>
</asp:Panel>
<asp:Panel ID="Panel3" runat="server">
<h2>Panel 3</h2>
</asp:Panel>
code behind:
Protected Sub CheckBox1_CheckedChanged(sender As Object, e As EventArgs) Handles CheckBox1.CheckedChanged
' we could use this one line
' Panel1.Visible = CheckBox1.Checked
' or
If CheckBox1.Checked Then
Panel1.Visible = True
Else
Panel1.Visible = False
End If
End Sub
Protected Sub CheckBox2_CheckedChanged(sender As Object, e As EventArgs) Handles CheckBox2.CheckedChanged
Panel2.Visible = CheckBox2.Checked
End Sub
Protected Sub CheckBox3_CheckedChanged(sender As Object, e As EventArgs) Handles CheckBox3.CheckedChanged
Panel3.Visible = CheckBox3.Checked
End Sub
We get this:
Do note, since the page just loaded, then NONE of my check box code has run. And in fact if I check ONE box, I get this:
So, in fact to hide the Panel 1, I can now un-check the first box, and get this:
Note how the panels are in a way "out of sync", since I don't really check, or do anything with the panels on startup, and thus they don't reflect the correct status.
In fact, untill I check, and un-check all 3, then at that point, they all work ok.
So, probably better would be to do this.
On the first page load (and ONLY ONLY first load), I would do this:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not IsPostBack Then
ShowPans()
End If
End Sub
Sub ShowPans()
Panel1.Visible = CheckBox1.Checked
Panel2.Visible = CheckBox2.Checked
Panel3.Visible = CheckBox3.Checked
End Sub
So, now on first page load - I hide/show the panels based on check box code, and now everything starts out "synced" up correctly
Do try a test blank page with above, but hiding and showing the panels should work.
Do note, that in MANY cases it is better to hide/show the panels and NOT use visibile. The reason for this is that any control marked as visibile = false IS NOT SENT to the browser. If you have some client side JavaScript running, or doing things, they will NOT be able to see, nor reference those panels.
So, in many cases, it is FAR better to hide, and NOT use Visible=false. As noted, this is VERY much a requement if you using client side JavaScript to manipulate such controls.
As a result, our code would now become this:
Protected Sub CheckBox1_CheckedChanged(sender As Object, e As EventArgs) Handles CheckBox1.CheckedChanged
If CheckBox1.Checked Then
Panel1.Style("display") = "normal"
Else
Panel1.Style("display") = "none"
End If
End Sub
Protected Sub CheckBox2_CheckedChanged(sender As Object, e As EventArgs) Handles CheckBox2.CheckedChanged
If CheckBox2.Checked Then
Panel2.Style("display") = "normal"
Else
Panel2.Style("display") = "none"
End If
End Sub
Protected Sub CheckBox3_CheckedChanged(sender As Object, e As EventArgs) Handles CheckBox3.CheckedChanged
' same as above 2 - but short hand code
Panel3.Style("display") = IIf(CheckBox3.Checked, "normal", "none")
End Sub
Now, you ONLY need to do the above if you using say JavaScript client side - I just wanted to make clear that using Visible can often be a issue, since as noted visible = false means the control is NOT sent nor rendered browser side - I spent a hard day of bugs learning this when I then started to write a lot of JavaScript.
Since, so far, this looks to be 100% server side code, so you can use .Visible.
but, do cook up a quick tiny test web page - play with above - make sure it works, and then try again on your code.
I have a GridView with a checkbox column. On clicking a button, all rows with the checkbox checked should be removed. I somehow stumbled upon a strange and hacky solution, and I have no idea why it works. I already searched through related SO questions already.
Related code:
Protected Sub Page_Init(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Init
' I have no idea why this is needed for the checkboxes to work...
Dim x = imageGridView.Rows
End Sub
Protected Sub RemoveButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles removeButton.Click
For Each row As GridViewRow In imageGridView.Rows
Dim selectCheckBox As CheckBox = DirectCast(row.Cells(0).FindControl("selectCheckBox"), CheckBox)
If selectCheckBox.Checked Then
Dim fileName As String = row.Cells(1).Text
ImageList.Remove(ImageList.FindLast(Function(r) r.FileName = fileName))
End If
Next
imageGridView.DataSource = ImageList
imageGridView.DataBind()
End Sub
Aspx:
<asp:GridView ID="imageGridView" runat="server">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<asp:CheckBox ID="selectCheckBox" runat="server" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
The line Dim x = imageGridView.Rows is needed for the rows to be removed. I found this after trying my RemoveButton_Click code in the Page_Init sub, then removing code until it didn't work anymore. Dim x = imageGridView is not enough, and it doesn't work to do the same thing in Page_Load.
My checkboxes are never disabled.
So, simply put, why is it necessary for me to reference imageGridView.Rows in the Page_Init for my code to work?
That is an interesting behavior. I reproduce the problem if I bind the data to the GridView in Page_Load on every postback. In that situation, the check boxes lose their selection state on postback, but not if we refer to imageGridView.Rows in Page_Init, as you observed.
The solution is to bind the data inside an If Not IsPostBack conditional block:
Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not IsPostBack Then
imageGridView.DataSource = ImageList
imageGridView.DataBind()
End If
End Sub
In that case, however, we must NOT refer to imageGridView.Rows in Page_Init. Doing so causes the check boxes to lose their selection state (!?!).
From the source code of the GridView (assuming that this source is reliable), I notice that accessing the Rows collection triggers a call to EnsureChildControls which then calls CreateChildControls. I haven't been able to step into the .NET code to see what happens at that point. Calling these methods in the Page_Init event handler may come earlier than expected in the life cycle of the GridView.
By the way, accessing the HeaderRow and the FooterRow properties also triggers a call to EnsureChildControls, and has the same effect on the selection status of the check boxes.
I am working on a web application (.net framework 4.0), my application role is to search in the active directory and returns the results in a SearchResultCollection.
My question is how to give my GridView the SearchResultCollection as a datasource?
First check that SearchResultsCollection inherits from IEnumerable:
http://msdn.microsoft.com/en-us/library/system.directoryservices.searchresultcollection(v=vs.110).aspx
It does, now you can use the following methods (taken from http://www.telerik.com/help/aspnet-ajax/grid-data-binding-basics.html):
NeedDataSource event - preferred method
The key to the advanced data binding of a RadGrid control is handling the NeedDataSource event. RadGrid fires the NeedDataSource event each time it needs to be bound to a data source. If, at the time of the event, the DataSource property is not set to a valid data source object, the grid will not behave correctly.
Protected Sub RadGrid1_NeedDataSource(ByVal source As Object, ByVal e As Telerik.Web.UI.GridNeedDataSourceEventArgs) Handles RadGrid1.NeedDataSource
' Ensure that SearchResultsCollection is accessible in your code-behind class or <script runat="server"> code block
RadGrid1.DataSource = SearchResultsCollection
End Sub
On Page_Load
Simple data-binding can be used in simple cases when you do not require the grid to perform complex operations such as: Inserting, deleting, and updating records through custom edit forms (WebUserControl or FormTemplate), Grouping, Hierarchy relations, Filtering, Sorting, Paging
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
RadGrid1.DataSource = SearchResultsCollection
End Sub
Edit:
Manipulate the results to get the information you need:
Private Sub rgItems_ItemDataBound(ByVal sender As Object, ByVal e As Telerik.Web.UI.GridItemEventArgs) Handles rgItems.ItemDataBound
Dim result As SearchResult = TryCast(e.Item.DataItem, SearchResult)
If searchResult IsNot Nothing Then
' Get info you need here, perhaps play with result.GetDirectoryEntry()
' Assign this data to variables, name, department , etc
' Use e.Item.FindControl("ltlDepartment").Text = department
End If
End Sub
Ensure that you define each one of these controls:
<telerik:RadGrid runat="server">
<telerik:GridTemplateColumn HeaderText="Department" UniqueName="Department">
<ItemTemplate>
<asp:Literal id="ltlDepartment" runat="server" />
</ItemTemplate>
</telerik:GridTemplateColumn>
</telerik:radGrid>
I am learning asp.net and needed to have a CheckBoxList which items will be initially selected if the are in a CSV string from a database.
I have got it working although I just wondered if I have gone about it the best way as it seemed a little long winded?
Thanks for any help provided.
ASPX
<asp:CheckBoxList ID="rh_type" runat="server" CssClass="chkbox"
RepeatLayout="Flow" CausesValidation="True">
<asp:ListItem>House</asp:ListItem>
<asp:ListItem>Flat/Apartment</asp:ListItem>
<asp:ListItem>Bungalow</asp:ListItem>
<asp:ListItem>Any</asp:ListItem>
</asp:CheckBoxList>
<br />
<br />
<asp:Button ID="Button1" runat="server" Text="Button" />
CODE
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim i As Integer
Dim str_rh_type As String = "House,Bungalow"
Dim split As String() = str_rh_type.Split(","c)
For Each s As String In split
'Response.Write(s & "<br />")
For i = 0 To rh_type.Items.Count - 1
If rh_type.Items(i).Text = s Then
rh_type.Items(i).Selected = True
End If
Next
Next s
End Sub
Thanks again
J.
Your code is functional but maybe some tweaking for maintainability would help. Also not sure you necessarily need nested loops to load your drop down items.
This should be just a reference point to make your own decisions on coding practices. Certainly what works for some doesn't work for others.
Here's how I'd code this...
ASP.NET Control:
<asp:CheckBoxList ID="CheckBoxListHomeType" runat="server"
CssClass="chkbox" RepeatLayout="Flow" CausesValidation="True" />
...
ID of CheckBoxListHomeType is easy to remember and intellisense will get me the rest of the way. (or another common approach would be cblHomeType as the ID). Getting intellisense to help on a name like rh_type may be just as easy but IDs that resemble what kind of control it is can really help when maintaining code
VB.NET:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not Page.IsPostBack Then
LoadHomeTypes()
End If
End Sub
Protected Sub LoadHomeTypes()
Dim houseTypes = "House,Bungalow,Flat/Apartment,Any"
For Each houseType As String In houseTypes.Split(",")
CheckBoxListHomeType.Items.Add(New ListItem(houseType))
Next
End Sub
Keeping the logic in a separate LoadHomeTypes function can make the code more readable.
Creating a new ListItem while iterating the list of homeTypes should remove the need to iterate over the CheckBoxList items, (if you need to clear out the existing ones you can add CheckBoxListHomeType.Items.Clear() to the top of the function)
the Not Page.IsPostBack check prevents the need for loading the drop down values every postback, unless you have need for them to change.
This is the good answers , try this
Dim ds As DataSet
ds = Insertstu.searchrec(txtsearch.Text)
txtnm.Text = ds.Tables(0).Rows(0)("stuname").ToString()
txtadd.Text = ds.Tables(0).Rows(0)("stuaddress").ToString()
txtph.Text = ds.Tables(0).Rows(0)("stuph").ToString()
rdobtnsex.Text = ds.Tables(0).Rows(0)("sex").ToString()
Dim arr As String()
Dim quali As String = ds.Tables(0).Rows(0)("qualified").ToString()
arr = quali.Split(",")
Dim i As Integer
For Each itm As String In arr
For i = 0 To chkqualify.Items.Count - 1
If chkqualify.Items(i).Text = itm Then
chkqualify.Items(i).Selected = True
End If
Next
Next
''chkqualify is checkboxlist id
I have a standard ASP.Net DataPager with a standard ListView (using a DataTable as a data source).
When I set PageSize="24" in the design code:
<asp:DataPager runat="server" ID="DataPager1" PagedControlID="ListView1" QueryStringField="page" PageSize="24" >
the paging works as advertised.
However, when I then change that in code, in the Page_Load, eg:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
DataPager1.PageSize = 48
End Sub
the paging ceases to work completely, while the initial loaded data set is indeed 48 items.
I can't see anything in the code which would affect this, so I'm wondering if I'm missing something - should I be changing something else?
Regards
Moo
Protected Sub DataPager1_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles DataPager1.Init
DataPager1.PageSize = 48
End Sub
I managed to get this working by setting the page size property in the init event for the datapager.
This sort of error I usually find is a data-binding issue... either binding when you shouldn't, or not re-binding when appropriate. Hard to tell from your little snippet of code.
I am unfamiliar with the DataPager object, but I suspect it must rebind the data when you set the PageSize. If so, then every time the page loads it is re-binding and you are losing events. Have you tried this?
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not IsPostBack
DataPager1.PageSize = 48
End If
End Sub