check Empty DataList

[sarabonn]

I am using ASP.NET and VB to display a message(label) while the datalist is empty like this

<asp:Label ID="lblEmpty" Text="No Data To Display"  runat="server" Visible='<%#bool.Parse((dlErgebnis.Items.Count==0).ToString()) %>'></asp:Label>

I am getting a error "the name bool is not declared".

What is causing this error?

[ThatThatGuy]

Visible='<%#bool.Parse((dlErgebnis.Items.Count==0) .ToString()) %>

this is where you're commiting the biggest mistake....

You can do the same via ternary operator like this

Visible='<%(dlErgebnis.Items.Count==0)?true:false;%>'>
 

Correct me if i was wrong

[sarabonn]

Hallo Thatthatguy ,

I have tried as you said iam getting the error as below

Error 1 object of type System.String can not dlErgebnis.Items.Count from its string representation '% (== 0)? True: false;%> for the Visible property to be created.

Thank you .

sarab

[semomaniz]

Try this

Visible='<%(dlErgebnis.Items.Count=0)?true:false;%>'>
 

Remove one of the equals to sign, Count is and integer not string.

[sarabonn]

Hallo Semomaniz,

Thank you for your reply.. i tried that also but not successful..

[semomaniz]

Why dont you do this in a code behind?

Put this code in page load event or right after you bind the control

 
If dlErgebnis.Items.Count= 0 then
   lblempty = "No data was found ";
 
 

Also refer to this posting http://bytes.com/topic/asp-net/answe...empty-datalist

[sarabonn]

Hallo semo,

Thanks for your reply. I have a problem again. if i put this code

 dlErgebnis.DataBind()
        If dlErgebnis.Items.Count <= 0 Then
            lbdata.Visible = True
            lbdata.Text = "Keine datei"
        Else
            lbdata.Visible = False
        End If

in datalist_load it works but when i put the code in the button_click it doesn't show the message in the label .. What is the mistake i am doing ?..

any idea..

[semomaniz]

Which button click event are you referring to? If the button binds the data to the data grid you dont have to put the code all you have to do is create a function that pulls the data from the database and binds the data to the datalist, put the datalist check inside the function after binding the data and then you can call the function from any where in the code and still achieve what you are looking for.

[sarabonn]

Hallo Semo,

This my aspx code.

<div id="Eingabe" runat="server">
        <p>Firma oder Person: </p>
        <asp:TextBox ID="tbSuchstring" width="400px" runat="server" />
        <asp:Button ID="btnSuchen" runat="server" Text="Suchen" />
        <asp:CustomValidator ID="CVtbSuchstring" runat="server" OnServerValidate="CVtbSuchstring_ServerValidate" />
 
    </div>
 
    <div id="Ergebnis" runat="server">
        <asp:DataList ID="dlErgebnis"  runat="server" DataSourceID="ObjectDataSource1">
            <ItemTemplate>
                Liste: <asp:Label ID="SLL_SPL_LIST_TYPELabel" runat="server" Text='<%# Eval("SLL_SPL_LIST_TYPE") %>' />
                <b><asp:Label ID="SLL_SPL_LAW1" runat="server" Text='<%# Eval("SLL_SPL_LAW1") %>' /></b>
                - Eintrag vom <asp:Label ID="SLL_SPL_ENTRY_DATE" runat="server" Text='<%# Eval("SLL_SPL_ENTRY_DATE", "{0:d}") %>' /><br />
                <asp:Label ID="SLL_SPL_NAME1Label" runat="server" Text='<%# Eval("SLL_SPL_NAME1") %>' />
                <asp:Label ID="SLL_SPL_NAME2Label" runat="server" Text='<%# Eval("SLL_SPL_NAME2") %>' /><br />
                <asp:Label ID="SLL_SPL_STREETLabel" runat="server" Text='<%# Eval("SLL_SPL_STREET") %>' />
                <asp:Label ID="SLL_SPL_HOUSE_NUMBERLabel" runat="server" Text='<%# Eval("SLL_SPL_HOUSE_NUMBER") %>' /><br />
                <asp:Label ID="SLL_SPL_CITYLabel" runat="server" Text='<%# Eval("SLL_SPL_CITY") %>' />
                <asp:Label ID="SLL_SPL_DISTRICTLabel" runat="server" Text='<%# Eval("SLL_SPL_DISTRICT") %>' /><br />
                <br />
                <br />
                </ItemTemplate>
               <FooterTemplate>
               </FooterTemplate>
           </asp:DataList>
        <asp:ObjectDataSource ID="ObjectDataSource1" runat="server" OldValuesParameterFormatString="original_{0}"
            SelectMethod="GetData" TypeName="DataSetComplianceTableAdapters.DataTable1TableAdapter">
            <SelectParameters>
                <asp:ControlParameter ControlID="tbSuchstring" Name="SLL_SPL_NAME1" PropertyName="Text"
                    Type="String" />
            </SelectParameters>
        </asp:ObjectDataSource>
 
    </div>

I think just the btn click will fetch the data. i only need to check the datalist is empty or not in the button click.

[semomaniz]

as i said earlier you will have to rebind the datagrid in you button click event and add the empty check code below the databinding.

[sarabonn]

Hallo Semo,

i did like that semo but still no output. here is my code

[Protected Sub btnSuchen_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnSuchen.Click
        dlErgebnis.DataBind()
        If dlErgebnis.Items.Count <= 0 Then
            lbdata.Visible = True
            lbdata.Text = "Keine datei"
        Else
            lbdata.Visible = False
        End If
    End Sub 

thank you

[semomaniz]

where is the datasource to bind the datalist?

[sarabonn]

Hallo Semo,

I Datasource i use the DatasetTableAdapter in the asp datasource tag as shown below

<asp:ObjectDataSource ID="ObjectDataSource1" runat="server" OldValuesParameterFormatString="original_{0}"
            SelectMethod="GetData" TypeName="DataSetComplianceTableAdapters.DataTable1TableAdapter">
            <SelectParameters>
                <asp:ControlParameter ControlID="tbSuchstring" Name="SLL_SPL_NAME1" PropertyName="Text"
                    Type="String" />
            </SelectParameters>
        </asp:ObjectDataSource>

Thank you.

[semomaniz]

You will also have to define the data source on your button click event for it to update.

[wayko]

bool.parse is a c command
boolean.parse is the vb equivalent