Page.Validate Method (System.Web.UI)

Validate Method

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Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

.NET Framework Class Library

Page..::.Validate Method

Instructs any validation controls included on the page to validate their assigned information.

Namespace: System.Web.UI
Assembly: System.Web (in System.Web.dll)

Syntax

Visual Basic (Declaration)

Public Overridable Sub Validate

Visual Basic (Usage)

Dim instance As Page

instance.Validate()

public virtual void Validate()

Visual C++

public:
virtual void Validate()

JScript

public function Validate()

Remarks

This method is invoked when a user clicks any ASP.NET server control that has the CausesValidation property set to true, which is the default. These include the Button, ImageButton, and LinkButton Web server controls, the HtmlInputButton, HtmlInputImage, and HtmlButton HTML server controls, and controls that can automatically post back to the server such as the TextBox, CheckBox, ListControl, and BulletedList controls.

To disable validation for any button control on the page, set the button control's CausesValidation property to false.

When this method is invoked, it iterates through the validation controls contained in the ValidatorCollection object associated with the Page..::.Validators property and invokes the validation logic for each validation control in the current validation group. The validation group is determined by the control that posted the page to the server. If no validation group is specified, then no validation group is used.

Note:
The behavior of page validation has changed. In ASP.NET 2.0, controls no longer call the Page..::.Validate()()() method; they use the Page..::.Validate(String) method instead. If you use the Page..::.Validate()()() method on an ASP.NET 2.0 page, validation groups are ignored and all controls are validated.

Notes to Inheritors:

The Validate method is not used by ASP.NET 2.0. When you are using ASP.NET 2.0, override the Validate(String) method to change page validation behavior.

Examples

The following code example calls the Validate method on a page in a scenario with several different validation groups defined.

Security Note:
This example has a text box that accepts user input, which is a potential security threat. By default, ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview.

Visual Basic

<%@ Page Language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

  Protected Sub Button_Click(ByVal sender As Object, ByVal e As System.EventArgs)

    Select Case CType(sender, Button).ID
      Case "Button1"
        If TextBoxValidator1.IsValid Then
          Label1.Text = "TextBox validates."
        Else
          Label1.Text = ""
          Label4.Text = ""
        End If
      Case "Button2"
        ' Must explicitly cause Validate here because 
        ' Button2 has CausesValidation set to false.
        Validate("Group2")
        If CustomValidator.IsValid Then
          Label2.Text = "CheckBox validates."
        Else
          Label2.Text = ""
          Label4.Text = ""
        End If
      Case Else
        Label1.Text = ""
        Label2.Text = ""
    End Select

  End Sub

  Protected Sub CustomValidator_ServerValidate(ByVal source As Object, ByVal args As System.Web.UI.WebControls.ServerValidateEventArgs)

    args.IsValid = (CheckBox1.Checked)

  End Sub

  Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)

    If (IsPostBack) Then

    ' Handle AutoPostBack TextBox.
      Validate("Group3")
      If (Page.IsValid) Then
        Label3.Text = "AutoPostBack TextBox validates."
      Else
        Label3.Text = ""
        Label4.Text = ""
      End If
    End If

  End Sub

  Protected Sub Button3_Click(ByVal sender As Object, ByVal e As System.EventArgs)

    Validate()
    If (Page.IsValid) Then
      Label4.Text = "All controls valid."
    Else
      Label1.Text = ""
      Label2.Text = ""
      Label3.Text = ""
      Label4.Text = ""
    End If

  End Sub

</script>

<html  >
<head runat="server">
    <title>Page Validate</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
      TextBox
      <asp:TextBox ID="TextBox1" ValidationGroup="Group1" runat="server"></asp:TextBox>
      <asp:RequiredFieldValidator Display="Static" ID="TextBoxValidator1" ValidationGroup="Group1" runat="server" ControlToValidate="TextBox1" ErrorMessage="(please enter some text)" EnableClientScript="False"></asp:RequiredFieldValidator>
      <br />
      CheckBox
      <asp:CheckBox ID="CheckBox1" ValidationGroup="Group2" runat="server" />
      <asp:CustomValidator ID="CustomValidator" ValidationGroup="Group2" runat="server" Text="(this option required)" OnServerValidate="CustomValidator_ServerValidate" EnableClientScript="False"></asp:CustomValidator>
      <br />
      <asp:Button ID="Button1" ValidationGroup="Group1" CausesValidation="true" runat="server" Text="Validate Group1 Controls" OnClick="Button_Click" />
      <asp:Label ID="Label1" runat="server"></asp:Label>
      <br />
      <asp:Button ID="Button2" ValidationGroup="Group2" CausesValidation="false" runat="server" Text="Validate Group2 Controls" OnClick="Button_Click" />
      <asp:Label ID="Label2" runat="server"></asp:Label>
      <br />
      <br />
      AutoPostBack TextBox
      <asp:TextBox AutoPostBack="true" ID="TextBox2" ValidationGroup="Group3" runat="server" CausesValidation="true"></asp:TextBox>
      <asp:RequiredFieldValidator ID="TextBoxValidator2" ValidationGroup="Group3" runat="server" ControlToValidate="TextBox2" ErrorMessage="(please enter some text)" EnableClientScript="False"></asp:RequiredFieldValidator>
      <asp:Label ID="Label3" runat="server"></asp:Label>
      <br />
      <br />
      <asp:Button ID="Button3" CausesValidation="true" runat="server" Text="Validate All Controls" OnClick="Button3_Click" />
      <asp:Label ID="Label4" runat="server"></asp:Label>

    </div>
    </form>
</body>
</html>

<%@ 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">

  protected void Button_Click(object sender, EventArgs e)
  {
    switch (((Button)sender).ID)
    {
      case "Button1":
        if (TextBoxValidator1.IsValid)
        {
          Label1.Text = "TextBox validates.";
        }
        else
        {
          Label1.Text = "";
          Label4.Text = "";
        }
        break;
      case "Button2":
        // Must explicitly cause Validate here because 
        // Button2 has CausesValidation set to false.
        Validate("Group2");
        if (CustomValidator.IsValid)
        {
          Label2.Text = "CheckBox validates.";
        }
        else
        {
          Label2.Text = "";
          Label4.Text = "";
        }
        break;
      default:
      Label1.Text = "";
      Label2.Text = "";
      break;

    }
  }

  // Custom validator for check box.
  protected void CustomValidator_ServerValidate(object source, ServerValidateEventArgs args)
  {
    args.IsValid = (CheckBox1.Checked == true);
  }

  protected void Page_Load(object sender, EventArgs e)
  {
    if (IsPostBack && Context.Request.Form["__EVENTTARGET"] == "TextBox2")
    {
      // Handle AutoPostBack TextBox.
      Validate("Group3");
      if (Page.IsValid)
      {
        Label3.Text = "AutoPostBack TextBox validates.";
      }
      else
      {
        Label3.Text = "";
        Label4.Text = "";
      }
    }

  }

  protected void Button3_Click(object sender, EventArgs e)
  {
    Validate();
    if (Page.IsValid)
      Label4.Text = "All controls valid.";
    else
    {
      Label1.Text = "";
      Label2.Text = "";
      Label3.Text = "";
      Label4.Text = "";
    }

  }
</script>

<html  >
<head runat="server">
    <title>Page Validate</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
      TextBox
      <asp:TextBox ID="TextBox1" ValidationGroup="Group1" runat="server"></asp:TextBox>
      <asp:RequiredFieldValidator Display="Static" ID="TextBoxValidator1" ValidationGroup="Group1" runat="server" ControlToValidate="TextBox1" ErrorMessage="(please enter some text)" EnableClientScript="False"></asp:RequiredFieldValidator>
      <br />
      CheckBox
      <asp:CheckBox ID="CheckBox1" ValidationGroup="Group2" runat="server" />
      <asp:CustomValidator ID="CustomValidator" ValidationGroup="Group2" runat="server" Text="(this option required)" OnServerValidate="CustomValidator_ServerValidate" EnableClientScript="False"></asp:CustomValidator>
      <br />
      <asp:Button ID="Button1" ValidationGroup="Group1" CausesValidation="true" runat="server" Text="Validate Group1 Controls" OnClick="Button_Click" />
      <asp:Label ID="Label1" runat="server"></asp:Label>
      <br />
      <asp:Button ID="Button2" ValidationGroup="Group2" CausesValidation="false" runat="server" Text="Validate Group2 Controls" OnClick="Button_Click" />
      <asp:Label ID="Label2" runat="server"></asp:Label>
      <br />
      <br />
      AutoPostBack TextBox
      <asp:TextBox AutoPostBack="true" ID="TextBox2" ValidationGroup="Group3" runat="server" CausesValidation="true"></asp:TextBox>
      <asp:RequiredFieldValidator ID="TextBoxValidator2" ValidationGroup="Group3" runat="server" ControlToValidate="TextBox2" ErrorMessage="(please enter some text)" EnableClientScript="False"></asp:RequiredFieldValidator>
      <asp:Label ID="Label3" runat="server"></asp:Label>
      <br />
      <br />
      <asp:Button ID="Button3" CausesValidation="true" runat="server" Text="Validate All Controls" OnClick="Button3_Click" />
      <asp:Label ID="Label4" runat="server"></asp:Label>

    </div>
    </form>
</body>
</html>

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Version Information

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

Reference

Page Class

Page Members

Validate Overload

System.Web.UI Namespace

ValidatorCollection

Page..::.Validators

IsValid