ASP.NET - How to Validate DropdownList Control
- Here i am going to explain that how to validate [DropdownList] control in ASP.NET
- Scenario is that when we provide Dropdown in our form , user have yo select one item from given list of items .
- Problem arise when user will not select any one , and by default initial value is selected
Like :
- Select city
- Select one item
- Select your choice
- To do this we need to set the requiredfieldvalidator ControlToValidate property value to DropDownList control's ID which dropdownlist control we want to validate. requiredfieldvalidator control's InitialValue property get or set the initial value of the associated input control. in this example code dropdownlist initial value is 'Choose One',
- Because we set this text for the dropdownlist control's first item Text property value. initial value is only used for information only, users need to select any one item from dropdownlist control other than it.
So here i am giving you a technique to resolve above error / problem.
<%@ Page Language="C#" %> <!DOCTYPE html> <script runat="server"> protected void Button1_Click(object sender, System.EventArgs e) { Label1.Text = "Your selected item is : " + DropDownList1.SelectedItem.Text.ToString(); } </script> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>How to validate a DropDownList in asp.net</title> </head> <body style="padding:25px"> <form id="form1" runat="server"> <div> <h2 style="color:MidnightBlue; font-style:italic;"> DropDownList Validation </h2> <hr width="450" align="left" color="Gainsboro" /> <asp:Label ID="Label1" runat="server" Font-Bold="true" Font-Names="Comic Sans MS" ForeColor="ForestGreen" Font-Italic="true" Font-Size="X-Large" /> <br /><br /><br /> <asp:DropDownList ID="DropDownList1" runat="server" Width="350" Font-Size="X-Large" Font-Names="Comic Sans MS" ForeColor="MidnightBlue" BackColor="FloralWhite" > <asp:ListItem Selected="True">Choose One</asp:ListItem> <asp:ListItem>BulletedList</asp:ListItem> <asp:ListItem>Button</asp:ListItem> <asp:ListItem>Calendar</asp:ListItem> <asp:ListItem>DataGrid</asp:ListItem> <asp:ListItem>DataList</asp:ListItem> <asp:ListItem>DataPager</asp:ListItem> </asp:DropDownList> <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="DropDownList1" InitialValue="Choose One" ErrorMessage="* Please select an item." ForeColor="Red" Font-Names="Impact" > </asp:RequiredFieldValidator> <br /><br /> <asp:Button ID="Button1" runat="server" Text="Validate DropDownList" OnClick="Button1_Click" Font-Bold="true" Font-Size="Large" ForeColor="DodgerBlue" Font-Names="Monaco" Height="45" Width="350" /> </div> </form> </body> </html>
Its time to execute the code , and test you get your desired solution .
If not feel free to ask me anytime .
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