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POError with Dropdownlist Control
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  1. POError with Dropdownlist Control
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    copied!<p>In <code>shownotice.aspx</code> page has a Repeater control to show the notice loaded from Database (sql server 2008) and a Dropdownlist control for filtering: <code>all notices</code>(default value = 0)<code>/lecturer's notices</code>(value=1)<code>/ student notices</code> (value=2).</p> <pre><code>&lt;asp:DropDownList ID="DropDownList" runat="server" OnSelectedIndexChanged="DropDownlist_Changed" AutoPostBack="true" &gt; &lt;asp:ListItem Selected="True" Value="0"&gt; All notice &lt;/asp:ListItem&gt; &lt;asp:ListItem Value="1"&gt; Lecturer &lt;/asp:ListItem&gt; &lt;asp:ListItem Value="2"&gt; Student &lt;/asp:ListItem&gt; &lt;/asp:DropDownList&gt; </code></pre> <p>NOTICE table in database</p> <pre><code> NOTICE(id, title, content,object) </code></pre> <p>object = <code>1</code> --> notice for lecturer</p> <p>object= <code>2</code>--> notice for student.</p> <p>Please take a look at my code below:</p> <pre><code>protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { bool check = BindRepeater(madoituong, maloai); if (check == false) LabelError.Text = "There is no notice."; } } private bool BindRepeater() { string sql = ""; string key = DropDownList.SelectedValue; if (key == "0") sql = "select * from NOTICE"; else sql = "select * from NOTICE where object=" + key; DataTable tb = EXECUTEQUERYSQL(sql); if (tb.Rows.Count &gt; 0) { Repeater1.DataSource = tb; Repeater1.DataBind(); return true; } else return false; } public void DropDownlist_Changed(Object sender, EventArgs e) { bool check = BindRepeater(); if (check == false) LabelError.Text = "There is no notice."; } </code></pre> <p>All I want is:</p> <ul> <li><p>when client accesses <code>shownotice</code> page -> key= 0 --> Repeater loads all notices in NOTICE table (both for lecturer and for student)</p></li> <li><p>Then client chooses <code>Lecturer</code> or <code>Student</code> to filtering and display notices by object. </p></li> </ul> <p>When I built this page, the program worked fine if it has some notices for lecturer (object=1) and some notices for student (object=2) in Database.</p> <p>But when it only has notices for lecturer or only notices for student--> program worked wrong. </p> <p><strong>For example:</strong></p> <p>There is only one record in NOTICE table:</p> <p>id= 1, title= aaa, content= holiday, object=1 </p> <p>When I choose Lecturer or Student --> it always show notice <code>aaa</code> , it should show messsage "There is no notice" when I choose <code>Student</code> option.</p> <p><strong>Try to debug:</strong></p> <p>When I choose <code>Student</code> option: <code>Datatable tb = null</code> and return <code>false</code>, the program jump into <code>if</code> statement and hit line: LabelError = "There is no notice."; But after finish debugging, the Repeater still shows notice <code>aaa</code> instead of message.</p> <p>Help!!! I really dont know why when I debug, the program hit the line LabelError = "There is no notice."; but then, there is no LabelError Message appear. Help!!!</p>
 

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