SqlMembershipProvider.ValidateUser(String, String) Method

Reference

Definition

Namespace:: System.Web.Security

Assembly:: System.Web.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Verifies that the specified user name and password exist in the SQL Server membership database.

public:
 override bool ValidateUser(System::String ^ username, System::String ^ password);

public override bool ValidateUser (string username, string password);

override this.ValidateUser : string * string -> bool

Public Overrides Function ValidateUser (username As String, password As String) As Boolean

Parameters

username: String

The name of the user to validate.

password: String

The password for the specified user.

Returns

Boolean

true if the specified username and password are valid; otherwise, false. A value of false is also returned if the user does not exist in the database.

Examples

The following code example shows the sign-in page for an ASP.NET application configured to use forms authentication and the SqlMembershipProvider. If the supplied user credentials are invalid, a message is displayed to the user. Otherwise, the user is redirected to the originally requested URL using the RedirectFromLoginPage method.

Note

This example uses the Membership class to call the SqlMembershipProvider specified as the defaultProvider in the Web.config file. If you need to access the default provider as the type SqlMembershipProvider, you can cast the Provider property of the Membership class. To access other configured providers as a specific provider type, you can access them by their configured name with the Providers property of the Membership class and cast them as the specific provider type.

<%@ Page Language="C#" %>
<%@ Import Namespace="System.Web.Security" %>

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

public void Login_OnClick(object sender, EventArgs args)
{
   if (Membership.ValidateUser(UsernameTextbox.Text, PasswordTextbox.Text))
      FormsAuthentication.RedirectFromLoginPage(UsernameTextbox.Text, NotPublicCheckBox.Checked);
   else
     Msg.Text = "Login failed. Please check your user name and password and try again.";
}


</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
  <title>Login</title>
</head>
<body>

<form id="form1" runat="server">
  <h3>Login</h3>

  <asp:Label id="Msg" ForeColor="maroon" runat="server" /><br />

  Username: <asp:Textbox id="UsernameTextbox" runat="server" /><br />
  Password: <asp:Textbox id="PasswordTextbox" runat="server" TextMode="Password" /><br />
 
  <asp:Button id="LoginButton" Text="Login" OnClick="Login_OnClick" runat="server" />
  <asp:CheckBox id="NotPublicCheckBox" runat="server" /> 
  Check here if this is <span style="text-decoration:underline">not</span> a public computer.

</form>

</body>
</html>

<%@ Page Language="VB" %>
<%@ Import Namespace="System.Web.Security" %>

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

Public Sub Login_OnClick(sender As Object, args As  EventArgs)

   If (Membership.ValidateUser(UsernameTextbox.Text, PasswordTextbox.Text)) Then
      FormsAuthentication.RedirectFromLoginPage(UsernameTextbox.Text, NotPublicCheckBox.Checked)
   Else
     Msg.Text = "Login failed. Please check your user name and password and try again."
   End If

End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
  <title>Login</title>
</head>
<body>

<form id="form1" runat="server">
  <h3>Login</h3>

  <asp:Label id="Msg" ForeColor="maroon" runat="server" /><br />

  Username: <asp:Textbox id="UsernameTextbox" runat="server" /><br />
  Password: <asp:Textbox id="PasswordTextbox" runat="server" TextMode="Password" /><br />
 
  <asp:Button id="LoginButton" Text="Login" OnClick="Login_OnClick" runat="server" />
  <asp:CheckBox id="NotPublicCheckBox" runat="server" /> 
  Check here if this is <span style="text-decoration:underline">not</span> a public computer.

</form>

</body>
</html>

Remarks

This method is called by the Membership class to validate user information for a user in the SQL Server database specified in the ASP.NET application's configuration file (Web.config).

When a user is successfully validated, the last activity date and last sign-in date values are updated to the current date and time in the database.

If an incorrect password is supplied to the ValidateUser method, the internal counter that tracks invalid password attempts is incremented by one. This can result in the user being locked out and unable to log on until the lock status is cleared by a call to the UnlockUser method. If the correct password is supplied and the user is not currently locked out, then the internal counters that track invalid password and password-answer attempts are reset to zero. For more information, see the MaxInvalidPasswordAttempts and PasswordAttemptWindow properties.

Leading and trailing spaces are trimmed from all parameter values.

Applies to

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