Lecture – Passing Variables in Web Forms

Passing Variables in Web Forms

Summary

This video (9 minutes) demonstrates how to pass a variable from a web form to another web form. The three methods demonstrated are (1) using the Session state, (2) Using HTTP query string method, and (3) using HTTP POST method.

Video

Code

         FormA.aspx<body>    <form id=”form1″ runat=”server” method=”post”>    <div style=”font-weight: 700″>        Enter Value to Transfer<asp:TextBox ID=”tbData” runat=”server”></asp:TextBox><br /><br />        <asp:Button ID=”btnSession” runat=”server”             Text=”Transfer Using Session Variable” onclick=”btnSession_Click” />        <asp:Button ID=”btnGet” runat=”server” Text=”HTTP Get Request”             onclick=”btnGet_Click” />        <asp:Button ID=”btnPost” runat=”server” Text=”HTTP Post Request”              PostBackUrl=”~/FormD.aspx” />    </div>    </form></body>
        FormA.cs      public partial class FormA : System.Web.UI.Page    {        protected void Page_Load(object sender, EventArgs e)        {        }        protected void btnSession_Click(object sender, EventArgs e)        {            string value = tbData.Text;            Session.Add(“val”, value);            Response.Redirect(“FormB.aspx”);        }        protected void btnGet_Click(object sender, EventArgs e)        {            Response.Redirect(“FormC.aspx?val=” + tbData.Text);        }          }
     FormB.aspx<body>    <form id=”form1″ runat=”server”>    <div>    You passed:         <asp:TextBox ID=”tbValue” runat=”server” ></asp:TextBox>    </div>    </form></body> 
    FormB.cs public partial class FormB : System.Web.UI.Page    {        protected void Page_Load(object sender, EventArgs e)        {            tbValue.Text=Session[“val”].ToString();        }           }
    FormC.aspx <body>    <form id=”form1″ runat=”server”>    <div>     You passed:         <asp:TextBox ID=”tbValue” runat=”server” ></asp:TextBox>    </div>    </form></body>
    FormC.cspublic partial class FormC : System.Web.UI.Page    {        protected void Page_Load(object sender, EventArgs e)        {            tbValue.Text = Request[“val”].ToString();        }    }
    FormD.aspx   <body>    <form id=”form1″ runat=”server”>    <div>        You passed:         <asp:TextBox ID=”tbValue” runat=”server” ></asp:TextBox>    </div>    </form></body>
     FormD.cspublic partial class FormD : System.Web.UI.Page     {         protected void Page_Load(object sender, EventArgs e)         {             string[] s = Request.Form.GetValues(“tbData”);             tbValue.Text = s[0];         }           }

Resources

How to Pass values Between ASP.Net Web Pages – http://msdn.microsoft.com/en-us/library/6c3yckfw.aspx 

HttpResponse Class – http://msdn.microsoft.com/en-us/library/system.web.httpresponse.aspx 

HttpRequest Class – http://msdn.microsoft.com/en-us/library/system.web.httprequest.aspx 

Http Session – http://msdn.microsoft.com/en-us/library/ms178581.aspx