How can I use a Timer Control to refresh a page automatically at a specified interval
<asp:DropDownList id=’DropDownList1′ runat=’server’ onChange=’SetClientRefresh(this);’> <asp:ListItem Value=’1000′>1 second</asp:ListItem> <asp:ListItem Value=’2000′>2 seconds</asp:ListItem> <asp:ListItem Value=’3000′>3 seconds</asp:ListItem> </asp:DropDownList> <script language=’javascript’> var cTimeOut = null; function SetClientRefresh(sel) { var newRefresh = sel.options[sel.selectedIndex].value; if (cTimeOut != null) { window.clearTimeout(cTimeOut); } cTimeOut = window.setTimeout(‘ReLoadPage()’, newRefresh); } function ReLoadPage() { window.location.reload(); } </script>
How to pop up a message box when no item in the dropdownlist is selected before postback?
Make sure to add a ListItem with Text=’Please Choose’ and Value =”. Add a RequiredFieldValidator with ControlToValidate= <Dropdownlist1> and Display=’Dynamic’ Add a ValidationSummary with ShowMessageBox =true <asp:DropDownList id=’DropDownList1′ runat=’server’> <asp:ListItem Value=”>Please Choose</asp:ListItem> <asp:ListItem Value=’Faq’>Faq</asp:ListItem> <asp:ListItem Value=’Tips’>Tips</asp:ListItem> <asp:ListItem Value=’Tricks’>Tricks</asp:ListItem> </asp:DropDownList> <asp:RequiredFieldValidator id=’RequiredFieldValidator1′ style=’Z-INDEX: 102; LEFT: 176px; POSITION: absolute; TOP: 48px’ runat=’server’ ErrorMessage=’Please Select an Item in the dropdownlist’ ControlToValidate=’DropDownList1′ Display=’Dynamic’></asp:RequiredFieldValidator> <asp:Button id=’Button1′ style=’Z-INDEX: 104; LEFT: 128px; POSITION: absolute; TOP: 16px’ runat=’server’ Text=’Button’></asp:Button> <asp:ValidationSummary id=’ValidationSummary1′ style=’Z-INDEX: 105; LEFT: 176px; POSITION: absolute; TOP: 72px’ runat=’server’ ShowMessageBox=’True’ ShowSummary=’False’></asp:ValidationSummary>
How can I make a Textbox a mandatory field if a checkbox is checked on a button click event in the client side?
<asp:TextBox id=’TextBox1′ style=’Z-INDEX: 101; LEFT: 32px; POSITION: absolute; TOP: 104px’ runat=’server’></asp:TextBox> <asp:CheckBox id=’CheckBox1′ style=’Z-INDEX: 102; LEFT: 24px; POSITION: absolute; TOP: 80px’ runat=’server’></asp:CheckBox> <asp:Button id=’Button1′ style=’Z-INDEX: 103; LEFT: 32px; POSITION: absolute; TOP: 144px’ runat=’server’ Text=’Button’></asp:Button> <script> function func1() { if(document.getElementById (‘CheckBox1’).checked == true) { if(document.getElementById(‘TextBox1’).value == ”) { alert(‘Enter something in textbox’); } } } </script> VB.NET Button1.Attributes.Add (‘onclick’ , ‘return func1()’); C# Button1.Attributes.Add (‘onclick’ , ‘return func1()’);
How to disable a Dropdownlist once someone has selected an item in the Dropdownlist
<asp:DropDownList id=’DropDownList1′ runat=’server’> <asp:ListItem Value=’Red’>Red</asp:ListItem> <asp:ListItem Value=’Blue’>Blue</asp:ListItem> <asp:ListItem Value=’Green’>Green</asp:ListItem> </asp:DropDownList> VB.NET DropDownList1.Attributes.Add(‘onChange’,’this.disabled=true;’ ) C# DropDownList1.Attributes.Add(‘onChange’,’this.disabled=true;’ );
How to change the BackgroundColor of a page based on the value selected in a DropdownList
<asp:DropDownList id=’DropDownList1′ runat=’server’ AutoPostBack=’True’> <asp:ListItem Value=’Red’>Red</asp:ListItem> <asp:ListItem Value=’Blue’>Blue</asp:ListItem> <asp:ListItem Value=’Green’>Green</asp:ListItem> </asp:DropDownList> VB.NET Page.RegisterClientScriptBlock(‘BodyStyle’, ‘<style type=’text/css’>body{background-color: ‘ + DropDownList1.SelectedItem.Value + ‘;}</style>’) C# Page.RegisterClientScriptBlock(‘BodyStyle’, ‘<style type=’text/css’>body{background-color: ‘ + DropDownList1.SelectedItem.Value + ‘;}</style>’);