ASP.NET Tutorial/Validation/CompareValidator

Содержание

1 asp:CompareValidator, Type="String", Operator="NotEqual" and ErrorMessage
2 Check birthday
3 CompareValidator compares the value of one form field against another form field.
4 CompareValidator for number, text and password
5 CompareValidator performs a comparison against a fixed value.
6 CompareValidator performs three different types of validations
7 CompareValidator with age field
8 Disable Client Validation
9 Making comparisons with the CompareValidator control
10 Set DeleteParameters, InsertParameters and UpdateParameters for asp:SqlDataSource
11 To specify the data types: Currency, Date, Double, Integer, String
12 Use CompareValidator to check password field and confirm password field
13 Using the CompareValidator to test values against other control values
14 Using the CompareValidator to validate against constants
15 What happens to asp:CompareValidator in the client side

asp:CompareValidator, Type="String", Operator="NotEqual" and ErrorMessage

<html><body>
   <form runat="server">
      <asp:Label id="lblMessage" runat="server" /><br>
      <asp:Panel id="Panel1" runat="server">
         <table>
         <tr>
            <td>
               First and last name:
            </td>
            <td>
               <asp:TextBox id="tbFName" runat="server" />
               <asp:TextBox id="tbLName" runat="server" /><br>
               <asp:RequiredFieldValidator runat="server" 
                  ControlToValidate="tbFName" 
                  ErrorMessage="First name required"/><br>
               <asp:RequiredFieldValidator runat="server" 
                  ControlToValidate="tbLName" 
                  ErrorMessage="Last name required"/><br>
               <asp:CompareValidator runat="server"
                  ControlToValidate="tbFName"
                  ControlToCompare="tbLName"
                  Type="String"
                  Operator="NotEqual"
                  ErrorMessage="First and last name cannot be the same" />
            </td>
         </tr>
         <tr>
            <td>
               <asp:Button id="Submit" runat="server" 
                  text="Add" />
            </td>
         </tr>
         </table>
      </asp:Panel>
   </form>
</body></html>

Check birthday

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="Login" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Simple Login Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        
          Username:<br />
          <asp:TextBox id="usernameTextBox" runat="server" />
          <asp:RequiredFieldValidator id="usernameReq"
              runat="server"
              ControlToValidate="usernameTextBox"
              ErrorMessage="Username is required!"
              SetFocusOnError="True" />
        
        
          Password and Confirmation:<br />
          <asp:TextBox id="passwordTextBox" 
              runat="server"
              TextMode="Password" />
          <asp:RequiredFieldValidator id="passwordReq"
              runat="server"
              ControlToValidate="passwordTextBox"
              ErrorMessage="Password is required!"
              SetFocusOnError="True" 
              Display="Dynamic" />
          <asp:TextBox id="confirmPasswordTextBox" runat="server"
              TextMode="Password" />
          <asp:RequiredFieldValidator id="confirmPasswordReq"
              runat="server" ControlToValidate="confirmPasswordTextBox"
              ErrorMessage="Password confirmation is required!"
              SetFocusOnError="True" Display="Dynamic" />
          <asp:CompareValidator id="comparePasswords" runat="server"
              ControlToCompare="passwordTextBox"
              ControlToValidate="confirmPasswordTextBox"
              ErrorMessage="Your passwords do not match up!"
              Display="Dynamic" />
        
        
          Birth Date:<br />
          <asp:TextBox id="birthDateTextBox" runat="server" />
          <asp:CompareValidator id="birthDateCheck" runat="server"
              Operator="DataTypeCheck" Type="Date"
              ControlToValidate="birthDateTextBox" 
              ErrorMessage="You must enter the date in a valid format!"
              SetFocusOnError="True" 
              Display="Dynamic" />
        
        
          <asp:Button id="submitButton" runat="server"
              Text="Submit" OnClick="submitButton_Click" />
        
    </div>
    </form>
</body>
</html>
File: Default.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class Login : System.Web.UI.Page
{
    protected void submitButton_Click(object sender, EventArgs e)
    {
        if (Page.IsValid)
        {
            submitButton.Text = "Valid";
        }
        else
        {
            submitButton.Text = "Invalid!";
        }
    }
}

CompareValidator compares the value of one form field against another form field.

<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Show Compare Values</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <asp:Label
        id="lblStartDate"
        Text="Start Date:"
        Runat="server" />
    <asp:TextBox
        id="txtStartDate"
        Runat="server" />
    <br /><br />
    <asp:Label
        id="lblEndDate"
        Text="End Date:"
        Runat="server" />
    <asp:TextBox
        id="txtEndDate"
        Runat="server" />
    <asp:CompareValidator
        id="cmpDate"
        Text="(End date must be greater than start date)"
        ControlToValidate="txtEndDate"
        ControlToCompare="txtStartDate"
        Type="Date"
        Operator="GreaterThan"
        Runat="server" />
    <asp:Button
        id="btnSubmit"
        Text="Submit"
        Runat="server" />
    </div>
    </form>
</body>
</html>

CompareValidator for number, text and password

<%@ Page Language="C#"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Using CompareValidator Control</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
      
      Age:<br />
      <asp:TextBox ID="txtAge" runat="server"></asp:TextBox>
      <asp:CompareValidator ID="compAge" runat="server" 
         ControlToValidate="txtAge" 
         ValueToCompare="18"
         Operator="LessThanEqual"
         SetFocusOnError="true"
         Text="You are too old to view this site" />
      
        
        Sales Date:<br />
        <asp:TextBox ID="txtDate" runat="server"></asp:TextBox>
        <asp:CompareValidator ID="compDate" runat="server" 
           ControlToValidate="txtDate" 
           Operator="DataTypeCheck"
           Type="Date"
           Text="Enter a valid date" />
        
              
        
        Quantity:<br />
        <asp:TextBox ID="txtQuantity" runat="server"></asp:TextBox>
           <asp:CompareValidator ID="compQuantity" runat="server" 
           ControlToValidate="txtQuantity" 
           Operator="DataTypeCheck"
           Type="Integer"
           Text="Enter a valid whole number" />   
        
        
        
        Enter Password:<br />
        <asp:TextBox ID="txtPass1" runat="server" TextMode="password"></asp:TextBox>
        
        
        Reenter Password:<br />
        <asp:TextBox ID="txtPass2" runat="server" TextMode="password"></asp:TextBox>
        
        
        <asp:CompareValidator ID="compPass" runat="server" 
           ControlToValidate="txtPass2" 
           Operator="Equal"
           ControlToCompare="txtPass1"
           Text="Passwords must match" />
        
      <asp:Button ID="btnSubmit" Text="Click this to test validation" runat="server" />
      
    </div>
    </form>
</body>
</html>

CompareValidator performs a comparison against a fixed value.

<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
    void Page_Load()
    {
        cmpDate.ValueToCompare = DateTime.Now.ToString("d");
    }
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Show Fixed Value</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <asp:Label
        id="lblDate"
        Text="Date:"
        AssociatedControlID="txtDate"
        Runat="server" />
    <asp:TextBox
        id="txtDate"
        Runat="server" />
    <asp:CompareValidator
        id="cmpDate"
        Text="(Date must be greater than now)"
        ControlToValidate="txtDate"
        Type="Date"
        Operator="GreaterThan"
        Runat="server" />
    <br /><br />
    <asp:Button
        id="btnSubmit"
        Text="Submit"
        Runat="server" />
    </div>
    </form>
</body>
</html>

CompareValidator performs three different types of validations

A data type check
Compare the value against a fixed value
Compare the value against another

Important properties
ControlToValidate: The ID of the form field being validated.
Text:              The error message.
Type:              The type of value being compared. 
                   Possible values are String, Integer, Double, Date, and Currency.
Operator:          The type of comparison to perform. 
                   Possible values are DataTypeCheck, Equal, GreaterThan, GreaterThanEqual, LessThan, LessThanEqual, and NotEqual.
ValueToCompare:    The fixed value.
ControlToCompare:  The ID of a control against which to compare.

<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Show Data Type Check</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <asp:Label
        id="lblBirthDate"
        Text="Birth Date:"
        AssociatedControlID="txtBirthDate"
        Runat="server" />
    <asp:TextBox
        id="txtBirthDate"
        Runat="server" />
    <asp:CompareValidator
        id="cmpBirthDate"
        Text="(Invalid Date)"
        ControlToValidate="txtBirthDate"
        Type="Date"
        Operator="DataTypeCheck"
        Runat="server" />
    <br /><br />
    <asp:Button
        id="btnSubmit"
        Text="Submit"
        Runat="server" />
    </div>
    </form>
</body>
</html>

CompareValidator with age field

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="Login" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Simple Login Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        
          Username:<br />
          <asp:TextBox id="usernameTextBox" runat="server" />
          <asp:RequiredFieldValidator id="usernameReq"
              runat="server"
              ControlToValidate="usernameTextBox"
              ErrorMessage="Username is required!"
              SetFocusOnError="True" />
        
        
          Password and Confirmation:<br />
          <asp:TextBox id="passwordTextBox" runat="server"
              TextMode="Password" />
          <asp:RequiredFieldValidator id="passwordReq"
              runat="server"
              ControlToValidate="passwordTextBox"
              ErrorMessage="Password is required!"
              SetFocusOnError="True" Display="Dynamic" />
          <asp:TextBox id="confirmPasswordTextBox" runat="server"
              TextMode="Password" />
          <asp:RequiredFieldValidator id="confirmPasswordReq"
              runat="server" 
              ControlToValidate="confirmPasswordTextBox"
              ErrorMessage="Password confirmation is required!"
              SetFocusOnError="True" 
              Display="Dynamic" />
          <asp:CompareValidator id="comparePasswords" runat="server"
              ControlToCompare="passwordTextBox"
              ControlToValidate="confirmPasswordTextBox"
              ErrorMessage="Your passwords do not match up!"
              Display="Dynamic" />
        
        <!-- Age -->
        
          Age:<br />
          <asp:TextBox id="ageTextBox" runat="server" />
          <asp:RequiredFieldValidator id="ageReq" runat="server"
              ControlToValidate="ageTextBox"
              ErrorMessage="Age is required!"
              SetFocusOnError="True" Display="Dynamic" />
          <asp:CompareValidator id="ageCheck" runat="server"
              Operator="GreaterThan" 
              Type="Integer"
              ControlToValidate="ageTextBox" 
              ValueToCompare="15"
              ErrorMessage="You must be 16 years or older to log in" />
        
        
          <asp:Button id="submitButton" runat="server"
              Text="Submit" 
              OnClick="submitButton_Click" />
        
    </div>
    </form>
</body>
</html>
File: Default.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class Login : System.Web.UI.Page
{
    protected void submitButton_Click(object sender, EventArgs e)
    {
        if (Page.IsValid)
        {
            submitButton.Text = "Valid";
        }
        else
        {
            submitButton.Text = "Invalid!";
        }
    }
}

Disable Client Validation

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="DisableClientValidation" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    
    Quantity:<br />
    <asp:TextBox ID="txtQuantity" runat="server"></asp:TextBox>
       <asp:CompareValidator ID="compQuantity" 
                             runat="server" 
                             ControlToValidate="txtQuantity" 
                             Operator="DataTypeCheck"
                             Type="Integer"
                             EnableClientScript="false"
                             Text="Enter a valid whole number" />   
    
    
    <asp:Button ID="btnSubmit" Text="Click this to test validation" runat="server" OnClick="btnSubmit_Click" />
    
    <asp:Label ID="labContent" runat="server" />      
    </form>
</body>
</html>
File: Default.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class DisableClientValidation : System.Web.UI.Page
{
    protected void btnSubmit_Click(object sender, EventArgs e)
    {
       if (IsValid)
       {
          int quantity = Convert.ToInt32(txtQuantity.Text);
          int unitCost = 5;
          int price = quantity * unitCost;
          labContent.Text = "Price for order is $" + price;
       }   
    }
}

Making comparisons with the CompareValidator control

<%@ Page Language="VB" %>
<script runat="server">
    Protected Sub Button1_Click(sender As Object, e As EventArgs)
       Label1.Text = "Passwords match"
    End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>CompareFieldValidator</title>
</head>
<body>
    <form id="Form1" runat="server">
        Age:
        <asp:TextBox ID="TextBox1" Runat="server"></asp:TextBox>
          &nbsp;
        <asp:CompareValidator ID="CompareValidator1" 
                              Runat="server"
                              Operator="GreaterThan" 
                              ValueToCompare="18"
                              ControlToValidate="TextBox1"
                              ErrorMessage="You must be older than 18 to join" 
                              Type="Integer">
        </asp:CompareValidator>
        
            <asp:Button ID="Button1" OnClick="Button1_Click" 
             Runat="server" Text="Login"></asp:Button>
        
        
            <asp:Label ID="Label1" Runat="server"></asp:Label>
        
    </form>
</body>
</html>

Set DeleteParameters, InsertParameters and UpdateParameters for asp:SqlDataSource

<%@ Page Language="VB" AutoEventWireup="false"%>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
            DeleteCommand="DELETE FROM [Books] WHERE [BookID] = @BookID" 
            InsertCommand="INSERT INTO [Books] ([Title], [Author], [YearPublished], [Price], [LastReadOn], [PageCount]) VALUES (@Title, @Author, @YearPublished, @Price, @LastReadOn, @PageCount)"
            SelectCommand="SELECT * FROM [Books]" 
            UpdateCommand="UPDATE [Books] SET [Title] = @Title, [Author] = @Author, [YearPublished] = @YearPublished, [Price] = @Price, [LastReadOn] = @LastReadOn, [PageCount] = @PageCount WHERE [BookID] = @BookID">
            <DeleteParameters>
                <asp:Parameter Name="BookID" Type="Int32" />
            </DeleteParameters>
            <UpdateParameters>
                <asp:Parameter Name="Title" Type="String" />
                <asp:Parameter Name="Author" Type="String" />
                <asp:Parameter Name="YearPublished" Type="Int32" />
                <asp:Parameter Name="Price" Type="Decimal" />
                <asp:Parameter Name="LastReadOn" Type="DateTime" />
                <asp:Parameter Name="PageCount" Type="Int32" />
                <asp:Parameter Name="BookID" Type="Int32" />
            </UpdateParameters>
            <InsertParameters>
                <asp:Parameter Name="Title" Type="String" />
                <asp:Parameter Name="Author" Type="String" />
                <asp:Parameter Name="YearPublished" Type="Int32" />
                <asp:Parameter Name="Price" Type="Decimal" />
                <asp:Parameter Name="LastReadOn" Type="DateTime" />
                <asp:Parameter Name="PageCount" Type="Int32" />
            </InsertParameters>
        </asp:SqlDataSource>
    
    </div>
        <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" BackColor="White"
            DataSourceID="SqlDataSource1">
            <FooterStyle BackColor="#CCCC99" />
            <Columns>
                <asp:CommandField ShowDeleteButton="True" ButtonType="Button" DeleteText="Delete Book" />
                <asp:BoundField DataField="BookID" HeaderText="BookID" InsertVisible="False" ReadOnly="True"
                    SortExpression="BookID" />
                <asp:BoundField DataField="Title" HeaderText="Title" SortExpression="Title" />
                <asp:BoundField DataField="Author" HeaderText="Author" SortExpression="Author" />
                <asp:BoundField DataField="YearPublished" HeaderText="YearPublished" SortExpression="YearPublished" />
                <asp:BoundField DataField="Price" HeaderText="Price" SortExpression="Price" />
                <asp:BoundField DataField="LastReadOn" HeaderText="LastReadOn" SortExpression="LastReadOn" />
                <asp:BoundField DataField="PageCount" HeaderText="PageCount" SortExpression="PageCount" />
            </Columns>
            <RowStyle BackColor="#F7F7DE" />
            <SelectedRowStyle BackColor="#CE5D5A" Font-Bold="True" ForeColor="White" />
            <PagerStyle BackColor="#F7F7DE" ForeColor="Black" HorizontalAlign="Right" />
            <HeaderStyle BackColor="#6B696B" Font-Bold="True" ForeColor="White" />
            <AlternatingRowStyle BackColor="White" />
        </asp:GridView>
    </form>
</body>
</html>
File: Web.config
<?xml version="1.0"?>
<configuration>
    <connectionStrings>
        <add name="ConnectionString" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\MyFirstDatabase.mdf;Integrated Security=True;User Instance=True"
            providerName="System.Data.SqlClient" />
    </connectionStrings>
</configuration>

To specify the data types: Currency, Date, Double, Integer, String

<%@ Page Language="VB" %>
<script runat="server">
    Protected Sub Button1_Click(sender As Object, e As EventArgs)
       Label1.Text = "Passwords match"
    End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>CompareFieldValidator</title>
</head>
<body>
    <form id="Form1" runat="server">
        Age:
        <asp:TextBox ID="TextBox1" Runat="server" MaxLength="3"/>
        <asp:CompareValidator ID="CompareValidator1" 
                              Runat="server"
                              ErrorMessage="You must enter a number"
                              ControlToValidate="TextBox1" 
                              Type="Integer"
                              Operator="DataTypeCheck"/>
        
            <asp:Button ID="Button1" OnClick="Button1_Click" 
             Runat="server" Text="Login"></asp:Button>
        
        
            <asp:Label ID="Label1" Runat="server"></asp:Label>
        
    </form>
</body>
</html>

Use CompareValidator to check password field and confirm password field

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="Login" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Simple Login Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        
          Username:<br />
          <asp:TextBox id="usernameTextBox" runat="server" />
          <asp:RequiredFieldValidator id="usernameReq"
              runat="server"
              ControlToValidate="usernameTextBox"
              ErrorMessage="Username is required!"
              SetFocusOnError="True" />
        
        
          Password and Confirmation:<br />
          <asp:TextBox id="passwordTextBox" runat="server"
              TextMode="Password" />
          <asp:RequiredFieldValidator id="passwordReq"
              runat="server"
              ControlToValidate="passwordTextBox"
              ErrorMessage="Password is required!"
              SetFocusOnError="True" Display="Dynamic" />
          <asp:TextBox id="confirmPasswordTextBox" runat="server"
              TextMode="Password" />
          <asp:RequiredFieldValidator id="confirmPasswordReq"
              runat="server" 
              ControlToValidate="confirmPasswordTextBox"
              ErrorMessage="Password confirmation is required!"
              SetFocusOnError="True" 
              Display="Dynamic" />
          <asp:CompareValidator id="comparePasswords" 
              runat="server"
              ControlToCompare="passwordTextBox"
              ControlToValidate="confirmPasswordTextBox"
              ErrorMessage="Your passwords do not match up!"
              Display="Dynamic" />
        
        
          <asp:Button id="submitButton" 
              runat="server"
              Text="Submit" 
              OnClick="submitButton_Click" />
        
    </div>
    </form>
</body>
</html>
File: Default.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class Login : System.Web.UI.Page
{
    protected void submitButton_Click(object sender, EventArgs e)
    {
        if (Page.IsValid)
        {
            submitButton.Text = "Valid";
        }
        else
        {
            submitButton.Text = "Invalid!";
        }
    }
}

Using the CompareValidator to test values against other control values

<%@ Page Language="VB" %>
<script runat="server">
    Protected Sub Button1_Click(sender As Object, e As EventArgs)
       Label1.Text = "Passwords match"
    End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>CompareFieldValidator</title>
</head>
<body>
    <form id="Form1" runat="server">
        
            Password<br>
            <asp:TextBox ID="TextBox1" Runat="server" 
             TextMode="Password"></asp:TextBox>
             &nbsp;
            <asp:CompareValidator ID="CompareValidator1" 
             Runat="server" ErrorMessage="Passwords do not match!" 
             ControlToValidate="TextBox2" 
             ControlToCompare="TextBox1"></asp:CompareValidator>
        
        
            Confirm Password<br>
            <asp:TextBox ID="TextBox2" Runat="server" 
             TextMode="Password"></asp:TextBox>
        
        
            <asp:Button ID="Button1" OnClick="Button1_Click" 
             Runat="server" Text="Login"></asp:Button>
        
        
            <asp:Label ID="Label1" Runat="server"></asp:Label>
        
    </form>
</body>
</html>

Using the CompareValidator to validate against constants

<%@ Page Language="VB" %>
<script runat="server">
    Protected Sub Button1_Click(sender As Object, e As EventArgs)
       Label1.Text = "Passwords match"
    End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>CompareFieldValidator</title>
</head>
<body>
    <form id="Form1" runat="server">
        Age:
        <asp:TextBox ID="TextBox1" Runat="server" MaxLength="3">
        </asp:TextBox>
        <asp:CompareValidator ID="CompareValidator1" 
                              Runat="server"
                              ErrorMessage="You must enter a number"
                              ControlToValidate="TextBox1" 
                              Type="Integer"
                              Operator="DataTypeCheck"/>
        
            <asp:Button ID="Button1" OnClick="Button1_Click" 
             Runat="server" Text="Login"></asp:Button>
        
        
            <asp:Label ID="Label1" Runat="server"></asp:Label>
        
    </form>
</body>
</html>

What happens to asp:CompareValidator in the client side

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="MyPage" %>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        Total number of children:
        <asp:TextBox ID="totalChildren" runat="server" Columns="4"></asp:TextBox>
        <asp:CompareValidator ID="CompareValidator1" runat="server" ControlToValidate="totalChildren"
            ErrorMessage="The total number of children must be a whole number greater than or equal to 0"
            Operator="GreaterThanEqual" Type="Integer" ValueToCompare="0"></asp:CompareValidator><br />
        <br />
        <asp:Button ID="btnSubmit" runat="server" Text="Click Me" />
        <br />
        <br />
        <asp:Label ID="results" runat="server"></asp:Label></div>
    </form>
</body>
</html>
File: Default.aspx.vb

Partial Class MyPage
    Inherits System.Web.UI.Page
    Protected Sub btnSubmit_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnSubmit.Click
        If Page.IsValid Then
            results.Text = "Input is valid..."
        Else
            results.Text = "Input is <b>not</b> valid..."
        End If
    End Sub
End Class

ASP.NET Tutorial/Validation/CompareValidator

Содержание

asp:CompareValidator, Type="String", Operator="NotEqual" and ErrorMessage

Check birthday

CompareValidator compares the value of one form field against another form field.

CompareValidator for number, text and password

CompareValidator performs a comparison against a fixed value.

CompareValidator performs three different types of validations

CompareValidator with age field

Disable Client Validation

Making comparisons with the CompareValidator control

Set DeleteParameters, InsertParameters and UpdateParameters for asp:SqlDataSource

To specify the data types: Currency, Date, Double, Integer, String

Use CompareValidator to check password field and confirm password field

Using the CompareValidator to test values against other control values

Using the CompareValidator to validate against constants

What happens to asp:CompareValidator in the client side

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