Concatenate @ character with textbox value before save it in database using C# in ASP.Net

Provide example.

for example, if a user types in his or her username the @ symbol will be attacked to the username and then sumited

diagram

------------------------------------
ID       USERNAME     
==========================================
1        @MIC

2        @STEVE

 <asp:TextBox ID="Username" runat="server"></asp:TextBox>

Hi micah,

Refer the below code.

HTML

<div>
    <asp:TextBox runat="server" ID="Username" AutoPostBack="true" OnTextChanged="TextChange" />
    <asp:HiddenField ID="newUsername" runat="server" />
    <asp:Button ID="Save" Text="Save" runat="server" OnClick="Save_Click" />
</div>

Code

C#

protected void TextChange(object sender, EventArgs e)
{
    newUsername.Value = "@" + Username.Text;
}

protected void Save_Click(object sender, EventArgs e)
{
    string value = newUsername.Value;
    ClientScript.RegisterClientScriptBlock(this.GetType(), "alert", "alert('" + value + "')", true);
}

VB.Net

Protected Sub TextChange(sender As Object, e As EventArgs)
	newUsername.Value = "@" + Username.Text
End Sub

Protected Sub Save_Click(sender As Object, e As EventArgs)
	Dim value As String = newUsername.Value
	ClientScript.RegisterClientScriptBlock(Me.[GetType](), "alert", (Convert.ToString("alert('") & value) + "')", True)
End Sub

Screenshot

Can it be submitted into database?

You need to write the code for saving on button click.

Remember you will get the value from hidden field as i am assigning the value to hiddenfield.

like string newUserName = newUsername.Value;

You can change as per your logic to get the new vale.