本文整理汇总了VB.NET中System.Web.Security.RoleProvider.RoleExists方法的典型用法代码示例。如果您正苦于以下问题：VB.NET RoleProvider.RoleExists方法的具体用法？VB.NET RoleProvider.RoleExists怎么用？VB.NET RoleProvider.RoleExists使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。
在下文中一共展示了RoleProvider.RoleExists方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的VB.NET代码示例。
示例1: RoleExists
Public Overrides Function RoleExists(ByVal rolename As String) As Boolean
If rolename Is Nothing OrElse rolename = "" Then _
Throw New ProviderException("Role name cannot be empty or null.")
Dim exists As Boolean = False
Dim conn As OdbcConnection = New OdbcConnection(connectionString)
Dim cmd As OdbcCommand = New OdbcCommand("SELECT COUNT(*) 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
Try
conn.Open()
Dim numRecs As Integer = CType(cmd.ExecuteScalar(), Integer)
If numRecs > 0 Then
exists = True
End If
Catch e As OdbcException
' Handle exception.
Finally
conn.Close()
End Try
Return exists
End Function