SqlMembershipProvider.GetPassword(String, String) 方法

參考

定義

命名空間:: System.Web.Security

組件:: System.Web.dll

重要

部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。

傳回 SQL Server 成員資格資料庫中所指定使用者名稱的密碼。

public:
 override System::String ^ GetPassword(System::String ^ username, System::String ^ passwordAnswer);

public override string GetPassword (string username, string passwordAnswer);

override this.GetPassword : string * string -> string

Public Overrides Function GetPassword (username As String, passwordAnswer As String) As String

參數

username: String

要為其擷取密碼的使用者。

passwordAnswer: String

使用者的密碼解答。

傳回

String

受指定使用者的密碼。

例外狀況

MembershipPasswordException

passwordAnswer 無效。

-或-

username 所識別的成員資格使用者已鎖定。

NotSupportedException

EnablePasswordRetrieval 設定為 false。

ProviderException

username 在成員資格資料庫中找不到。

-或-

從資料庫擷取密碼時發生錯誤。

ArgumentException

其中一個參數值超過所允許的最大長度。

-或-

username 為空字串 ("")、包含逗號或超過 256 個字元。

-或-

passwordAnswer 為空字串，且 RequiresQuestionAndAnswer 為 true。

-或-

passwordAnswer 大於 128 個字元。

-或-

passwordAnswer 的已編碼版本長度大於 128 個字元。

ArgumentNullException

username 為 null。

-或-

passwordAnswer 是 null，而 RequiresQuestionAndAnswer 是 true。

範例

下列程式代碼範例會擷取指定使用者名稱的密碼，並在電子郵件訊息中傳送給使用者。

注意

對於需要高安全性的網站，不建議使用電子郵件以純文本傳回密碼。針對高安全性網站，建議您使用加密來傳回密碼，例如 SSL。

注意

這個範例會使用 Membership 類別，呼叫SqlMembershipProvider指定為 defaultProvider Web.config 檔案中的。如果您需要存取預設提供者做為類型 SqlMembershipProvider，您可以轉換 Provider 類別的 Membership 屬性。若要以特定提供者類型存取其他已設定的提供者，您可以使用類別 Providers 的 Membership 屬性來存取這些提供者，並將其轉換成特定提供者類型。

<%@ Page Language="C#" %>
<%@ Import Namespace="System.Web.Security" %>
<%@ Import Namespace="System.Net.Mail" %>
<!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 Page_Load(object sender, EventArgs args)
{
  if (!Membership.EnablePasswordRetrieval)
  {
    FormsAuthentication.RedirectToLoginPage();
  }

  Msg.Text = "";

  if (!IsPostBack)
  {
    Msg.Text = "Please enter a user name.";
  }
  else
  {
    VerifyUsername();
  }
}


public void VerifyUsername()
{
    MembershipUser user = Membership.GetUser(UsernameTextBox.Text, false);

    if (user == null)
    {
      Msg.Text = "The user name " + Server.HtmlEncode(UsernameTextBox.Text) + " was not found. Please check the value and re-enter.";

      QuestionLabel.Text = "";
      QuestionLabel.Enabled = false;
      AnswerTextBox.Enabled = false;
      EmailPasswordButton.Enabled = false;
    }
    else
    {
      QuestionLabel.Text = user.PasswordQuestion;
      QuestionLabel.Enabled = true;
      AnswerTextBox.Enabled = true;
      EmailPasswordButton.Enabled = true;
    }
}


public void EmailPassword_OnClick(object sender, EventArgs args)
{
  // Note: Returning a password in clear text using email is not recommended for
  // sites that require a high level of security.

  try
  {
    string password = Membership.Provider.GetPassword(UsernameTextBox.Text, AnswerTextBox.Text);
    MembershipUser u = Membership.GetUser(UsernameTextBox.Text);
    EmailPassword(u.Email, password);
    Msg.Text = "Your password was sent via email.";
  }
  catch (MembershipPasswordException e)
  {
    Msg.Text = "The password answer is incorrect. Please check the value and try again.";
  }
  catch (System.Configuration.Provider.ProviderException e)
  {
    Msg.Text = "An error occurred retrieving your password. Please check your values " +
               "and try again.";
  }
}


private void EmailPassword(string email, string password)
{
  try
  {
    MailMessage Message = new MailMessage("administrator", email);
    Message.Subject = "Your Password";
    Message.Body = "Your password is: " + Server.HtmlEncode(password);

    SmtpClient SmtpMail = new SmtpClient("SMTPSERVER");
    SmtpMail.Send(Message);
  }
  catch 
  {
    Msg.Text = "An exception occurred while sending your password. Please try again.";
  }
}

</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>Sample: Retrieve Password</title>
</head>
<body>

<form id="form1" runat="server">
  <h3>Retrieve Password</h3>

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

  Username: <asp:Textbox id="UsernameTextBox" Columns="30" runat="server" AutoPostBack="true" />
            <asp:RequiredFieldValidator id="UsernameRequiredValidator" runat="server"
                                        ControlToValidate="UsernameTextBox" ForeColor="red"
                                        Display="Static" ErrorMessage="Required" /><br />

  Password Question: <b><asp:Label id="QuestionLabel" runat="server" /></b><br />

  Answer: <asp:TextBox id="AnswerTextBox" Columns="60" runat="server" Enabled="false" />
          <asp:RequiredFieldValidator id="AnswerRequiredValidator" runat="server"
                                      ControlToValidate="AnswerTextBox" ForeColor="red"
                                      Display="Static" ErrorMessage="Required" Enabled="false" /><br />

  <asp:Button id="EmailPasswordButton" Text="Email My Password" 
              OnClick="EmailPassword_OnClick" runat="server" Enabled="false" />

</form>

</body>
</html>


<%@ Page Language="VB" %>

<%@ Import Namespace="System.Web.Security" %>
<%@ Import Namespace="System.Net.Mail" %>

<!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 Page_Load(ByVal sender As Object, ByVal args As EventArgs)

    If Not Membership.EnablePasswordRetrieval Then
      FormsAuthentication.RedirectToLoginPage()
    End If

    Msg.Text = ""

    If Not IsPostBack Then
      Msg.Text = "Please enter a user name."
    Else
      VerifyUsername()
    End If

  End Sub


  Private Sub VerifyUsername()

    Dim user As MembershipUser = Membership.GetUser(UsernameTextBox.Text, False)

    If user Is Nothing Then
      Msg.Text = "The user name " & Server.HtmlEncode(UsernameTextBox.Text) & " was not found. Please check the value and re-enter."

      QuestionLabel.Text = ""
      QuestionLabel.Enabled = False
      AnswerTextBox.Enabled = False
      EmailPasswordButton.Enabled = False
    Else
      QuestionLabel.Text = user.PasswordQuestion
      QuestionLabel.Enabled = True
      AnswerTextBox.Enabled = True
      EmailPasswordButton.Enabled = True
    End If

  End Sub


  Public Sub EmailPassword_OnClick(ByVal sender As Object, ByVal args As EventArgs)

    ' Note: Returning a password in clear text using email is not recommended for
    ' sites that require a high level of security.

    Try
      Dim password As String = Membership.Provider.GetPassword(UsernameTextBox.Text, AnswerTextBox.Text)
      Dim u As MembershipUser = Membership.GetUser(UsernameTextBox.Text)
      EmailPassword(u.Email, password)
      Msg.Text = "Your password was sent via email."
    Catch e As MembershipPasswordException
      Msg.Text = "The password answer is incorrect. Please check the value and try again."
    Catch e As System.Configuration.Provider.ProviderException
      Msg.Text = "An error occurred retrieving your password. Please check your values " & _
                 "and try again."
    End Try

  End Sub


  Private Sub EmailPassword(ByVal email As String, ByVal password As String)

    Try
      Dim Message As MailMessage = New MailMessage("administrator", email)
      Message.Subject = "Your Password"
      Message.Body = "Your password is: " & Server.HtmlEncode(password)
      
      Dim SmtpMail As SmtpClient = New SmtpClient("SMTPSERVER")
      SmtpMail.Send(Message)
    Catch
      Msg.Text = "An exception occurred while sending your password. Please try again."
    End Try

  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
  <title>Sample: Retrieve Password</title>
</head>
<body>
  <form id="form1" runat="server">
    <h3>
      Retrieve Password</h3>
    <asp:Label ID="Msg" runat="server" ForeColor="maroon" /><br />
    Username:
    <asp:TextBox ID="UsernameTextBox" Columns="30" runat="server" AutoPostBack="True" />
    <asp:RequiredFieldValidator ID="UsernameRequiredValidator" runat="server" ControlToValidate="UsernameTextBox"
      ForeColor="red" Display="Static" ErrorMessage="Required" /><br />
    Password Question: <b>
      <asp:Label ID="QuestionLabel" runat="server" /></b><br />
    Answer:
    <asp:TextBox ID="AnswerTextBox" Columns="60" runat="server" Enabled="False" />
    <asp:RequiredFieldValidator ID="AnswerRequiredValidator" runat="server" ControlToValidate="AnswerTextBox"
      ForeColor="red" Display="Static" ErrorMessage="Required" Enabled="False" /><br />
    <asp:Button ID="EmailPasswordButton" Text="Email My Password" OnClick="EmailPassword_OnClick"
      runat="server" Enabled="False" />
  </form>
</body>
</html>

備註

類別會 MembershipUser 呼叫這個方法，以從 ASP.NET 應用程式組態檔 (Web.config) 中指定的 SQL Server 資料庫擷取使用者的密碼。

如果提供不正確的密碼答案給 GetPassword 方法，追蹤無效密碼響應嘗試的內部計數器會遞增一個。這可能會導致使用者遭到鎖定，且無法在方法呼叫 UnlockUser 清除鎖定狀態之前登入。如果提供正確的密碼答案且使用者目前未鎖定，則追蹤無效密碼回應嘗試的內部計數器會重設為零。如需詳細資訊，請參閱 MaxInvalidPasswordAttempts 和 PasswordAttemptWindow 屬性。

您可以直接呼叫 GetPassword 方法，方法是先透過 Provider 類別的屬性取得實例的Membership參考SqlMembershipProvider。

PasswordFormat如果屬性設定Hashed為，則GetPassword方法無法擷取密碼。哈希密碼會以單向方式加密，而且無法解密。 PasswordFormat如果屬性設定Hashed為，且 EnablePasswordRetrieval 設定true為，ProviderException則會在初始化提供者時擲回。

前置和尾端空格會從所有參數值修剪。

適用於

另請參閱

ASP.NET 成員資格簡介

共用方式為

SqlMembershipProvider.GetPassword(String, String) 方法

定義

參數

傳回

例外狀況

範例

備註

適用於

另請參閱

其他資源