RoleProvider.DeleteRole(String, Boolean) 方法

定义

命名空间:

System.Web.Security

程序集:

System.Web.ApplicationServices.dll

从数据源中删除已配置的 applicationName 的一个角色。

public:
 abstract bool DeleteRole(System::String ^ roleName, bool throwOnPopulatedRole);

public abstract bool DeleteRole (string roleName, bool throwOnPopulatedRole);

abstract member DeleteRole : string * bool -> bool

Public MustOverride Function DeleteRole (roleName As String, throwOnPopulatedRole As Boolean) As Boolean

参数

roleName

String

要删除的角色的名称。

throwOnPopulatedRole

Boolean

若为 true，则在 roleName 具有一个或多个成员时引发异常，且不删除 roleName。

返回

Boolean

若已成功删除此角色，则为 true；否则为 false。

示例

下面的代码示例演示 方法的示例 DeleteRole 实现。

public override bool DeleteRole(string rolename, bool throwOnPopulatedRole)
{
  if (!RoleExists(rolename))
  {
    throw new ProviderException("Role does not exist.");
  }

  if (throwOnPopulatedRole && GetUsersInRole(rolename).Length > 0)
  {
    throw new ProviderException("Cannot delete a populated role.");
  }

  OdbcConnection conn = new OdbcConnection(connectionString);
  OdbcCommand cmd = new OdbcCommand("DELETE FROM Roles "  +
                                    " WHERE Rolename = ? AND ApplicationName = ?", conn);

  cmd.Parameters.Add("@Rolename", OdbcType.VarChar, 255).Value = rolename;
  cmd.Parameters.Add("@ApplicationName", OdbcType.VarChar, 255).Value = ApplicationName;

  OdbcCommand cmd2 = new OdbcCommand("DELETE FROM UsersInRoles "  +
                                     " WHERE Rolename = ? AND ApplicationName = ?", conn);

  cmd2.Parameters.Add("@Rolename", OdbcType.VarChar, 255).Value = rolename;
  cmd2.Parameters.Add("@ApplicationName", OdbcType.VarChar, 255).Value = ApplicationName;

  try
  {
    conn.Open();

    cmd2.ExecuteNonQuery();
    cmd.ExecuteNonQuery();
  }
  catch (OdbcException)
  {
    // Handle exception.

    return false;
  }
  finally
  {
    conn.Close();      
  }

  return true;
}

Public Overrides Function DeleteRole(ByVal rolename As String, ByVal throwOnPopulatedRole As Boolean) As Boolean
    If Not RoleExists(rolename) Then
        Throw New ProviderException("Role does not exist.")
    End If

    If throwOnPopulatedRole AndAlso GetUsersInRole(rolename).Length > 0 Then
        Throw New ProviderException("Cannot delete a populated role.")
    End If

    Dim conn As OdbcConnection = New OdbcConnection(connectionString)
    Dim cmd As OdbcCommand = New OdbcCommand("DELETE FROM Roles " & _
                                             " WHERE Rolename = ? AND ApplicationName = ?", conn)

    cmd.Parameters.Add("@Rolename", OdbcType.VarChar, 255).Value = rolename
    cmd.Parameters.Add("@ApplicationName", OdbcType.VarChar, 255).Value = ApplicationName

    Dim cmd2 As OdbcCommand = New OdbcCommand("DELETE FROM UsersInRoles " & _
                                              " WHERE Rolename = ? AND ApplicationName = ?", conn)

    cmd2.Parameters.Add("@Rolename", OdbcType.VarChar, 255).Value = rolename
    cmd2.Parameters.Add("@ApplicationName", OdbcType.VarChar, 255).Value = ApplicationName

    Try
        conn.Open()

        cmd2.ExecuteNonQuery()
        cmd.ExecuteNonQuery()
    Catch e As OdbcException
        ' Handle exception.

        Return False
    Finally
        conn.Close()
    End Try

    Return True
End Function

注解

DeleteRole 由 DeleteRole 类的 DeleteRoleRoles 和 方法调用，以从配置的 ApplicationName的数据源中删除指定角色。

从数据源中删除角色时，请确保同时删除配置的 applicationName的用户名与已删除角色之间的任何关联。

如果 throwOnPopulatedRole 为 true，并且参数标识 roleName 的角色具有一个或多个成员，则引发 ProviderException 并不删除该角色。 如果 throwOnPopulatedRole 为 false，则无论角色是否为空，都将其删除。

如果指定的角色名称不存在、为 null或为空字符串，建议提供程序引发异常。

另请参阅

• 实现角色提供程序