Edit

Share via

Page.Validate Method

  • Reference

Definition

Namespace:
System.Web.UI
Assembly:
System.Web.dll

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

Overloads

Validate()

Instructs any validation controls included on the page to validate their assigned information.
Validate(String)

Instructs the validation controls in the specified validation group to validate their assigned information.

Validate()

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

C# 
public virtual void Validate();

Examples

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

Important

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.

ASP.NET (C#) 
<%@ 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 xmlns="http://www.w3.org/1999/xhtml" >
<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>

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.

See also

Applies to

.NET Framework 4.8.1 and other versions
Product Versions
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1

Validate(String)

Instructs the validation controls in the specified validation group to validate their assigned information.

C# 
public virtual void Validate(string validationGroup);

Parameters

validationGroup
String

The validation group name of the controls to validate.

Examples

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

Important

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.

ASP.NET (C#) 
<%@ 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 xmlns="http://www.w3.org/1999/xhtml" >
<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>

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.

The Validate method validates the specified validation group. After calling the Validate method on a validation group, the IsValid method will return true only if both the specified validation group and the validation group of the control that caused the page to be posted to the server are valid.

See also

Applies to

.NET Framework 4.8.1 and other versions
Product Versions
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1