Develop Reference

How to hide table rows in a DataList if column data returns null from SQL Server

I need to hide table rows in a DataList if column data returns null from SQL Server (for each individual column). I have it working successfully but this method will be very tedious as I have about 100 rows in my table. Surely there is a simpler way.
Here is my C# code:
protected void DataList1_ItemDataBound1(object sender, DataListItemEventArgs e)
{
if ((String.IsNullOrEmpty(((Label)e.Item.FindControl("lblAccountStatus")).Text)))
{
HtmlTableRow row = (HtmlTableRow)e.Item.FindControl("rowAccountStatus");
row.Visible = false;
}
if ((String.IsNullOrEmpty(((Label)e.Item.FindControl("lblAccountName")).Text)))
{
HtmlTableRow row = (HtmlTableRow)e.Item.FindControl("rowAccountName");
row.Visible = false;
}
}
Here is my webform markup:
<asp:DataList ID="DataListAccount" runat="server" OnItemDataBound="DataList1_ItemDataBound1">
<ItemTemplate>
<tr>
<td style="width: 171px">Account Status:</td>
<td style="width: 220px">
<asp:Label ID="lblAccountStatus" runat="server" Text='<%# Eval("ACCOUNT_STATUS") %>'></asp:Label>
</td>
</tr>
<tr id="rowAccountName">
<td style="width: 171px">Account Status:</td>
<td style="width: 220px">
<asp:Label ID="lblAccountName" runat="server" Text='<%# Eval("ACCOUNT_NAME") %>'></asp:Label>
</td>
</tr>
</ItemTemplate>
</asp:DataList>

You can wrap the ItemTemplate contents with a PlaceHolder and use a Ternary Operator to set the visibility.
<asp:PlaceHolder ID="PlaceHolder1" runat="server" Visible='<%# !string.IsNullOrEmpty(Eval("ACCOUNT_STATUS").ToString()) ? true : false %>'>
<tr>
<td style="width: 171px">Account Status:</td>
<td style="width: 220px">
<asp:Label ID="lblAccountStatus" runat="server" Text='<%# Eval("ACCOUNT_STATUS") %>'></asp:Label>
</td>
</tr>
</asp:PlaceHolder>
But I would recommend you make sure you filter the source data of empty items. Something like
SELECT * FROM accounts WHERE account_status IS NOT NULL

just modify this code by adding multiple conditions
string value = Convert.ToString( row["MyColumn"]);
if (string.IsNullOrEmpty(value))

ASP.NET (C#) - ListView

In past, i worked on ListViews (.net 2.0) using a custom Template field but what i am trying to achieve here is the following
I am now working on .net 4.6
So basically a list which shows items like above and on mouse-hover few options show up as shown in the following screenshot
I also have to trigger those option to do different things -
How can I do that in asp.net, may I please have some code references.
Cheers
P.S.
This is a rough example of how i am creating the List Item Template (as requested)
<asp:ListView ID="ListView1" runat="server" DataSourceID="SqlDataSource1">
<AlternatingItemTemplate>
<table >
<tr>
<td ><asp:Image ID="image1" ImageUrl='<%# Bind("url") %>' runat="server" Width="98px" /> </td>
<td><h2><asp:Label ID="_label" runat="server" Text ='<%# Bind("title") %>'></asp:Label></h2><asp:Label ID="Label1" runat="server" Text ='<%# Bind("description") %>'></asp:Label></td>
</tr>
</table>
</AlternatingItemTemplate>
<EmptyDataTemplate>
No data was returned.
</EmptyDataTemplate>
<ItemSeparatorTemplate>
<br />
</ItemSeparatorTemplate>
<ItemTemplate>
<table >
<tr>
<td ><asp:Image ID="image1" ImageUrl='<%# Bind("url") %>' runat="server" Width="98px" /> </td>
<td><h2><asp:Label ID="_label" runat="server" Text ='<%# Bind("title") %>'></asp:Label></h2><asp:Label ID="Label1" runat="server" Text ='<%# Bind("description") %>'></asp:Label></td>
</tr>
</table>
</ItemTemplate>
<LayoutTemplate>
<ul id="itemPlaceholderContainer" runat="server" style="">
<li runat="server" id="itemPlaceholder" />
</ul>
<div style="">
</div>
</LayoutTemplate>
</asp:ListView>
I can add any html formatting to this template e,g i can add ASP:button etc but i don't know how to trigger those to perform certain tasks.

One easy way to achieve your requirement is to keep those buttons there but invisible and show them up when the parent container is hovered. following as a quick sample
aspx
<asp:ListView ID="ListView1" runat="server">
<ItemTemplate>
<tr class="row-data">
<td>
<asp:Label ID="NameLabel" runat="server" Text='<%# Eval("Name") %>' />
</td>
<td>
<asp:Label ID="PositionLabel" runat="server" Text='<%# Eval("Position") %>' />
</td>
<td>
<div class="btn-area">
<asp:Button runat="server" Text="Button1" />
<asp:Button runat="server" Text="Button2" />
</div>
</td>
</tr>
</ItemTemplate>
<LayoutTemplate>
<table id="itemPlaceholderContainer" runat="server" border="0" style="">
<tr runat="server" style="">
<th runat="server">
Name
</th>
<th runat="server">
Position
</th>
<th>
</th>
</tr>
<tr id="itemPlaceholder" runat="server">
</tr>
</table>
</LayoutTemplate>
</asp:ListView>
css
.btn-area
{
display: none;
}
.row-data:hover .btn-area
{
display: block;
}
code-behind
protected void Page_Load(object sender, EventArgs e)
{
ListView1.DataSource = new List<dynamic>() {
new { Name = "Andy", Position = "PG"},
new { Name = "Bill", Position = "SD"},
new { Name = "Caroline", Position = "Manager"}
};
ListView1.DataBind();
}
UPDATE
ListView ItemCommand can capture the postback by button pressed and CommandName makes you able to recognize which button fired it.
<asp:Button runat="server" Text="Button1" CommandName="c1" />
<asp:Button runat="server" Text="Button2" CommandName="c2" />
code-behind
protected void ListView1_ItemCommand(object sender, ListViewCommandEventArgs e)
{
if (e.CommandName == "c1")
{
// do something when button1 pressed
}
else if (e.CommandName == "c1")
{
// do something when button2 pressed
}
}

In Paged Listview CheckBox_CheckedChanged event not working

The Problem is when I check the checkbox it works great, but when I check the checkbox on next page. previous page check boxes gets unchecked.
Checked box Checked/Unchecked event fires CheckedChanged event. But when I check the checkbox in listview next page of listview it uncheck's the checkboxes of listview previous Page.
ListView.aspx Code
<table class=" example1 table table-bordered table-striped">
<thead>
<tr>
<th>Sr no.</th>
<th>Parent Category</th>
<th>Title</th>
<th>Description</th>
<th>Image</th>
<th>Show on Homepage</th>
<th>Edit</th>
<th>Delete</th>
</tr>
</thead>
<tbody>
<asp:ListView ID="ListCourse" runat="server" OnItemCommand="ListCourse_ItemCommand" DataKeyNames="CID">
<LayoutTemplate>
<tr id="ItemPlaceholder" runat="server">
</tr>
</LayoutTemplate>
<ItemTemplate>
<tr class="gradeA">
<td>
<asp:Label ID="lblSrno" runat="server" Text='<%# Container.DataItemIndex+1 %>'></asp:Label>
</td>
<td>
<asp:Label ID="lbl" runat="server" Text='<%# GetCourse(Convert.ToInt32( Eval("CatID"))) %>'></asp:Label>
</td>
<td>
<asp:Label ID="Lbltitle" runat="server" Text='<%# Eval("Title") %>'></asp:Label>
<asp:Label ID="lablc" runat="server" Visible="false" Text='<%# Eval("CID") %>'></asp:Label>
</td>
<td>
<asp:Label ID="lblDescrption" runat="server" Text='<%# (Eval("Description").ToString().Length <=200)?Eval("Description").ToString(): Eval("Description").ToString().Substring(0, 200) + "..."%>'></b></asp:Label>
</td>
<td>
<img class="img_show " src="/Gallery/<%# Eval("Image")%>">
</td>
<td>
<asp:CheckBox ID="CheckCourse" runat="server" Style="margin-left: 50px;" OnCheckedChanged="CheckCourse_CheckedChanged" AutoPostBack="true" />
</td>
<td>
<asp:LinkButton ID="LinkEdit" runat="server" PostBackUrl='<%# "Add_New_Course.aspx?ID="+ Eval("CID")%>'>Edit</asp:LinkButton>
</td>
<td>
<asp:LinkButton ID="LinkDelete" runat="server" CommandName="DeleteCourse" CommandArgument='<%# Eval("CID") %>' OnClientClick='return confirm("Do you want to delete record ??")'> Delete</asp:LinkButton>
</td>
</tr>
</ItemTemplate>
</asp:ListView>
</tbody>
</table>
Code Behind CheckedChanged
protected void CheckCourse_CheckedChanged(object sender, EventArgs e)
{
CheckBox checkhome = (CheckBox)sender;
ListViewItem item = (ListViewItem)checkhome.NamingContainer;
ListViewDataItem dataItem = (ListViewDataItem)item;
string code = ListCourse.DataKeys[dataItem.DisplayIndex].Value.ToString();
int CID = Convert.ToInt32(code);
Course_Master objnew = DB.Course_Master.Single(p => p.CID == CID);
bool IsHome = CheckOnHome(CID);
if (IsHome == true)
{
if (checkhome.Checked == false)
{
objnew.ShowOnHomePage = false;
}
}
else
{
if (checkhome.Checked == true)
{
objnew.ShowOnHomePage = true;
}
}
DB.SaveChanges();
}

It doesn't fire because when the postback fires the server doesn't know the previous state of the checkbox, so it doesn't know if it's changed or not.
Try to set the default value to false and it should work
<asp:CheckBox ID="CheckCourse" runat="server" Checked="false" Style="margin-left: 50px;" OnCheckedChanged="CheckCourse_CheckedChanged" AutoPostBack="true" />

You need to save ids somewhere of checked item from the list. As when you move to the page 2 of ListView it lost its previous state.
Store data in viewstate and load it from there. To read and to bind it, you would need to handle PagePropertiesChanging and ItemDataBound event handlers of ListView.
Here is a good explaination regarding Maintaining the state of checkboxes in ListView
Please give +1 if it helped. Cheers!

Thank you Guys for the help. I solved it using some simple procedure's by removing the check-boxes from the ListView and adding text instead of it regarding whether the checkbox is checked or not(Yes/No). As I thought it will the easiest way to solve my problem.

Repeater inside another repeater. access an event values

I have an repeater inside another repeater. The second repeater have an checkbox event "isChecked_OnCheckedChanged". My problem is there. When this event occurs I need to access the value of the variable "lblName" and also the value of the variable "lblID" in parent repeater.
<asp:Repeater ID="rptOne" OnItemDataBound="populateSecondRepeater" runat="server">
<HeaderTemplate>
<table s>
</HeaderTemplate>
<ItemTemplate>
<tr>
<td>
<asp:Label ID="lblID" runat="server" Text='<%# Eval("ID") %>'></asp:Label>
</td>
<td style="width: 15%; vertical-align: top;">
<asp:Repeater ID="rptTwo" runat="server">
<HeaderTemplate>
<table>
</HeaderTemplate>
<ItemTemplate>
<tr>
<td style="width: 85%;">
<img runat="server" src='<%# Eval("Img") %>' alt="#" id="img_flag" /></td>
<td style="width: 15%; padding-right: 40px">
<asp:Label ID="lblName" runat="server" Style="display: none;" Text='<%# Eval("IDName") %>'></asp:Label>
<asp:CheckBox ID="check" runat="server" AutoPostBack="True" Checked='<%# Eval("isChecked") %>' OnCheckedChanged="isChecked_OnCheckedChanged" />
</td>
</tr>
</ItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:Repeater>
</td>
</tr>
</ItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:Repeater>
I can access the value of the variable "lblName", but how do I access the values ​​of the parent repeater?
protected void isChecked_OnCheckedChanged(object sender, EventArgs e)
{
CheckBox chk = (sender as CheckBox);
RepeaterItem item = chk.NamingContainer as RepeaterItem;
if (item != null)
{
Label lbl = (Label) item.FindControl("lblName");
}
}
thank you.

There are multiple ways to do this. You can add something like ParentID property to your data model, set that to the value you want and bind that to a hidden field next to the lblName label.
Alternatively, use a <tr runat="server" id="rptOneRow"> for each item in rptOne, and jump up in isChecked_OnCheckedChanged from the RepeaterItem until you find such row. Then use FindControl to find the lblID.
Or see here how to access the data directly - Accessing parent data in nested repeater, in the HeaderTemplate.

Many textboxes with the same ID

I have the code below:
<%for (int index = 1; index < 7; ++index) {%>
<tr>
<td>
<div class="indicacao_gdp">
<asp:TextBox ReadOnly="true" ID="inp_txt_indicacao_<%= index %>" CssClass="inp_txt_indicacao" runat="server" MaxLength="12"></asp:TextBox>
</div>
</td>
<td>
<div class="codigo_debito_credito_gdp">
<asp:TextBox ReadOnly="true" ID="inp_txt_codigo_debito_credito_<%= index %>" CssClass="inp_txt_codigo_debito_credito" runat="server" MaxLength="2"></asp:TextBox>
</div>
</td>
<td>
<div class="descricao_debito_credito_gdp">
<asp:TextBox ReadOnly="true" ID="inp_txt_descricao_debito_credito_<%= index %>" CssClass="inp_txt_descricao_debito_credito" runat="server" MaxLength="2"></asp:TextBox>
</div>
</td>
<td>
<div class="valor_debito_credito_gdp">
<asp:TextBox ReadOnly="true" ID="inp_txt_valor_debito_credito_inteiro_<%= index %>" CssClass="inp_txt_valor_inteiro" runat="server" MaxLength="8"></asp:TextBox>
,
<asp:TextBox ReadOnly="true" ID="inp_txt_valor_debito_credito_decimal_<%= index %>" CssClass="inp_txt_valor_decimal" runat="server" MaxLength="2"></asp:TextBox>
</div>
</td>
</tr>
<%}%>
But, the code not working...
Parser Error Message: 'inp_txt_indicacao_<%= index %>' is not a valid identifier.
How I solved?

Use the PlaceHolder control and dynamically add TextBox controls to it from code-behind. In code-behind you can easily set an ID and whatever other properties you like.
See MSDN: Add Controls to an ASP.NET Web Page Programmatically.

Why do you need to do this? If you use runat="server" the controls will never have the same ID. If you wrap these text-boxes in a container with a class you can easily obtain data from these elements through jQuery.

When you use runat="server" you are creating .net object and not actual html.
You have two options, you can use a Repeater and set the id to ID="inp_txt_indicacao" (.net will take care of making it unique).
Or instead of having <asp:TextBox you put regular
<input type="textbox" id="inp_txt_indicacao_<%= index %>" />
Repeater
There's a lot of good tutorial online but here's a quick understanding.
To use a repeater, you'll need to put your data in a list of some sort.
Public Class TestClass
Public Sub New(ByVal v1 As String, ByVal v2 As String)
Value1 = v1
Value2 = v2
End Sub
Public Property Value1() As String
Public Property Value2() As String
End Class
Dim tc As New List(Of TestClass)
tc.Add(New TestClass("aa", "bb"))
tc.Add(New TestClass("cc", "dd"))
tc.Add(New TestClass("ee", "ff"))
You just need to bind the data to the repeater
rpData.DataSource = tc
rpData.DataBind()
<asp:Repeater ID="rpData" runat="server">
<HeaderTemplate>
<table>
<tr>
<th>Header 1</th>
<th>Header 2</th>
</tr>
</HeaderTemplate>
<ItemTemplate>
<tr>
<td><asp:TextBox ID="txtValue1" Text='<%# Bind("Value1") %>' runat="server" /></td>
<td><asp:TextBox ID="txtValue2" Text='<%# Bind("Value2") %>' runat="server" /></td>
</tr>
</ItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:Repeater>