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Login form in ASP.Net

Anonymous User24279 27-Jul-2010

Login form in ASP.Net

Design view of login form

Login form designing include a login page (shown above) , a page where user will be redirected after successful login and a sign out page which will be displayed after signing out.

Design source for login page (Default.aspx)

 

<body>
    <form id="form1" runat="server"
   
    style="position:absolutetop185pxleft407pxwidth305pxheight147pxbackground-color#FFFFCC;">
    <p>
        &nbsp;</p>
    <p>
        <asp:Label ID="Label2" runat="server" Text="Password"
            style="position:absolutetop77pxleft30px;"></asp:Label>
        <asp:Label ID="Label1" runat="server" Text="User Name"
            style="position:absolutetop35pxleft30px;"></asp:Label>
        <asp:TextBox ID="txtPassword" runat="server"
            style="position:absolutetop75pxleft116pxwidth163px;" TabIndex="2"
            TextMode="Password"></asp:TextBox>
        <asp:TextBox ID="txtUserName" runat="server"
            style="position:absolutetop33pxleft117pxwidth164px;" TabIndex="1"></asp:TextBox>
        <asp:Button ID="btnLogin" runat="server" onclick="btnLogin_Click"
            style="z-index1left216pxtop103pxpositionabsolutewidth60pxheight22px"
            TabIndex="3" Text="Login" />
    </p>
    <p>
        <asp:Label ID="Label3" runat="server"
            style="position:absolutetop161pxleft5pxwidth295px;" ForeColor="Red"></asp:Label>
    </p>
    </form>
</body>
 
Screen shot of the above source

Login form in ASP.Net 

Asp.net code for login page (Default.aspx.cs)

 

protected void Page_Load(object sender, EventArgs e)
        { 
//checking whether session object is null or not. If null then label message
//will display the following message else it will not display anything.
            if (Session["uname"] == null)
                Label3.Text= "Please enter User Name and Password!";
            else
                Label3.Text=””;    
        }
 
//code when login button is clicked
        protected void btnLogin_Click(object sender, EventArgs e)
        {          
            try
            {
//creating connection to the database
 
                string sqlString= "Server=abc\\SQLEXPRESS; Database=proj1; User Id=sa;Password=sa";
                SqlConnection con= new SqlConnection(sqlString);
                con.Open();
 
//executing command to fetch record only if username and password, provided
//by the user matches with the database.
 
                SqlCommand cmd= new SqlCommand("select UserName, Password from login where UserName='" + txtUserName.Text.Trim() + "' and Password='" + txtPassword.Text + "'", con);
                SqlDataReader rdr =cmd.ExecuteReader();
//checking whether data reader contains any row.
                if (rdr.HasRows)
                {
//creating session object to pass value from this page another page.
                    Session["uname"] =txtUserName.Text;   
//redirecting to next page after successful login
                    Response.Redirect("redir.aspx");
                   
                }
                else
                {                   
//if data reader doesn’t contains any row, it means user name or password is
//incorrect
                    txtUserName.Text= "";
                    txtPassword.Text= "";
                    Label3.Text= "User Name/Password not correct";
                  
                }
            }
            catch (Exception ex)
            {
                Response.Write(ex.Message);
            }
        }

   

Once the login page is displayed we need to design a  page to which the user will be redirected after successful login.

Design source for redirected page (redir.aspx)

 

<body>
    <form id="form1" runat="server">
    <p>
        <asp:Label ID="Label1" runat="server" Text="Label"
            style="position:absolutetop20pxleft23pxwidth218px;"></asp:Label>
    </p>
   <a href="signout.aspx">
        <asp:Label ID="Label2" runat="server" Text="Signout"
            style="position:absolutetop64pxleft23pxwidth51px;"></asp:Label>
   </a>
    </form>
</body>
Screen shot of the above source

 Login form in ASP.Net

Asp.net code for redirected page (redir.aspx.cs)

 

protected void Page_Load(object sender, EventArgs e)
        {  
 
 
//checking whether session object contains value or not. If it contains value
//then name of the user logged on will be displayed otherwise message message
//“you are not logged in” will be displayed.
        
            if ((string)Session["uname"] != null)
                Label1.Text = "Welcome " + (string)Session["uname"];
            else
                Label1.Text = "You are not logged in";
            
//in this instead of giving the current date we gave the date in the past so
//it confirms the expiration of page. So that allowing for time differences,
//rather than specify a static date. If your page is viewed by a browser in a
//very different time-zone.
            Response.ExpiresAbsolute=DateTime.Now.AddDays(-1d);
 
//Some IIS internals experts revealed this can be a very touchy parameter to
//rely upon and usually requires a rather “large" negative number or
//pedantically, that would be a very small number
            Response.Expires =-1500;
 
// It tells the browser not to cache the page.
//Things can work with only one line of code
//i.e.    Response.CacheControl = "no-cache";
//But it is good practice to delete the existing page from cache.
//This code will tell the server not to cache this page, due to this when
//user clicks the Back button browser will not find the page in cache and
//then will go to server side to get the page
 
            Response.CacheControl = "no-cache";
            if (Session["uname"] == null)
            {
                Response.Redirect("default.aspx");
            }
            Session["uname"] = null;         
        }
Design source for sign out page (signout.aspx)
<body>
    <p>
        You are successfully signed out.</p>
    <p>
        To sign in again click <a href="Default.aspx"> here.</a></p>  
</body>

 

Screen shot of the above source

 Login form in ASP.Net

Asp.net code for sign out page (signout.aspx.cs)

 

protected void Page_Load(object sender, EventArgs e)
        {
            Response.ExpiresAbsolute= DateTime.Now.AddDays(-1d);
            Response.Expires= -1500;
            Response.CacheControl= "no-cache";
        }

Screen shots

 Login form in ASP.Net

 Login form in ASP.Net

 Login form in ASP.Net

 


Updated 07-Sep-2019
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