Content

• Register and Login System : Practical Example
• Validations in ASP.NET

Register and Login System : Practical Example

• Create Registration Form- Name,Email,Contact,Department,Password
• Login Functionality
• Update Profile

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Validations in ASP.NET

Validation is important part of any web application. User's input must always be validated before sending across different layers of the application.

Validation is of two types :

Client Side

• Client side validation dependent on browser and scripting language support.
• Client side validation is considered convenient for users as they get instant feedback. The main advantage is that it prevents a page from being postback to the server until the client validation is executed successfully.

Server Side

• For developer point of view server side is preferable because it will not fail, it is not dependent on browser and scripting language.

We can use ASP.NET validation, which will ensure client, and server validation. It work on both end; first it will work on client validation and than on server validation. At any cost server validation will work always whether client validation is executed or not. So you have a safety of validation check.

Validation Controls in ASP.NET

There are six types of validation controls in ASP.NET

The below table describes the controls and their work,

Validation Control	Description
RequiredFieldValidation	Makes an input control a required field
CompareValidator	Compares the value of one input control to the value of another input control or to a fixed value
RangeValidator	Checks that the user enters a value that falls between two values
RegularExpressionValidator	Ensures that the value of an input control matches a specified pattern
CustomValidator	Allows you to write a method to handle the validation of the value entered
ValidationSummary	Displays a report of all validation errors occurred in a Web page

Example :

Frond-End code

<div class="container">
    <div class="form-group">
        <label for="email">Name:</label>
        <asp:TextBox ID="txtname" runat="server" CssClass="form-control"></asp:TextBox>


    </div>
    <div class="form-group">
        <label for="email">Password:</label>
        <asp:TextBox ID="txtpassword1" runat="server" CssClass="form-control"></asp:TextBox>


    </div>
    <div class="form-group">
        <label for="email">Confirm Password:</label>
        <asp:TextBox ID="txtpassword2" runat="server" CssClass="form-control"></asp:TextBox>


    </div>
    <div class="form-group">
        <label for="email">Age:</label>
        <asp:TextBox ID="txtage" runat="server" CssClass="form-control"></asp:TextBox>


    </div>
    <div class="form-group">
        <label for="email">Email:</label>
        <asp:TextBox ID="txtemail" runat="server" CssClass="form-control"></asp:TextBox>


    </div>
    <div class="form-group">
        <label for="email">Username:</label>
        <asp:TextBox ID="txtusername" runat="server" CssClass="form-control"></asp:TextBox>


    </div>
    <asp:Button ID="btnsubmit" runat="server" CssClass="btn btn-primary" Text="Submit" />
    <div>
        <div>
        </div>
    </div>

    <br />
    <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ErrorMessage="Please Enter Name"
        ControlToValidate="txtname"></asp:RequiredFieldValidator><br />
    <asp:CompareValidator ID="CompareValidator1" runat="server" ErrorMessage="Password Not Matches"
        ControlToValidate="txtpassword1" ControlToCompare="txtpassword2"></asp:CompareValidator><br />
    <asp:RangeValidator ID="RangeValidator1" runat="server" ErrorMessage="Please enter age between 18-100"
        ControlToValidate="txtage" MaximumValue="100" MinimumValue="18" Type="Integer"></asp:RangeValidator><br />
    <asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server"
        ErrorMessage="Please Enter Valid email-id" ControlToValidate="txtemail"
        ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*"></asp:RegularExpressionValidator>
    <br />
    <asp:CustomValidator ID="CustomValidator1" runat="server" OnServerValidate="UserCustomValidate"
        ControlToValidate="txtusername" ErrorMessage="User ID should have atleast a capital, small and digit and should be greater than 5 and less than 26 letters" SetFocusOnError="True"></asp:CustomValidator>
    <hr />

    <asp:ValidationSummary ID="ValidationSummary1" runat="server" />
</div>

Back-End code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
            
public partial class Validations : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
            
    }
            
    protected void UserCustomValidate(object source, ServerValidateEventArgs args)
    {
        string str = args.Value;
        args.IsValid = false;
        //checking for input length greater than 6 and less than 25 characters  
        if (str.Length < 6 || str.Length > 25)
        {
            return;
        }
        //checking for a atleast a single capital letter  
        bool capital = false;
        foreach (char ch in str)
        {
            if (ch >= 'A' && ch <= 'Z')
            {
                capital = true;
                break;
            }
        }
        if (!capital)
        {
            return;
        }
        //checking for a atleast a single lower letter  
        bool lower = false;
        foreach (char ch in str)
        {
            if (ch >= 'a' && ch <= 'z')
            {
                lower = true;
                break;
            }
        }
        if (!lower)
        {
            return;
        }
        bool digit = false;
        foreach (char ch in str)
        {
            if (ch >= '0' && ch <= '9')
            {
                digit = true;
                break;
            }
        }
        if (!digit)
        {
            return;
        }
        args.IsValid = true;
    } 
}