Accessing CodeBehind Variables or C# Variables, Methods in ASPX Page in ASP.Net

Sometimes, we will have requirements to access codebehind variable in ASPX page. It can be done by the following syntax.

<% =VarName %>

The codebehind variable should be public variable to access in ASPX page.

ASPX

     <div><%=Name %></div>

CodeBehind

public partial class _Default : System.Web.UI.Page

{

    public string Name = "ASP.Net";

Calling CodeBehind Method in ASPX

CodeBehind

public DataTable GetAllRoles()

    {

        SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["Sql"].ConnectionString);

        con.Open();

        SqlCommand com = new SqlCommand("SP_GetAllRoles", con);

        com.CommandType = CommandType.StoredProcedure;

        SqlDataAdapter ada = new SqlDataAdapter(com);

        DataTable dt = new DataTable();

        ada.Fill(dt);

        return dt;

    }

ASPX

<asp:DropDownList ID="ddlRoles" DataSource='<%# GetAllRoles() %>'

DataTextField="Role"  DataValueField="RoleID"

 runat="server">

</asp:DropDownList>

The Codebehind method should be public to access from ASPX page.