请优化以下vb代码 Private Sub MainForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Dim datestr As String = "" datestr = Format(Now(), "yyyy/MM/dd H:mm:ss") Me.ToolStripStatusLabel4.Text = "时间：" & datestr Me.ToolStripStatusLabel3.Text = "当前用户：" & RealName & "(" & RoleName & ")" If RoleName = "管理者" Then 系统管理ToolStripMenuItem.Visible = True 数据录入ToolStripMenuItem.Visible = True Else 系统管理ToolStripMenuItem.Visible = False 数据录入ToolStripMenuItem.Visible = False End If End Sub

可以通过以下几个方式优化这段代码：

1. 使用字符串插值代替字符串拼接，使代码更简洁易懂。

2. 将获取当前时间和设置状态栏文本的操作封装成单独的函数，提高代码的可维护性。

3. 使用布尔值代替重复的可见性设置代码块，使代码更简洁。

下面是优化后的代码：

Private Sub MainForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    SetStatusBarText()
    SetMenuVisibility()
End Sub

Private Sub SetStatusBarText()
    Dim datestr As String = Format(Now(), "yyyy/MM/dd H:mm:ss")
    Me.ToolStripStatusLabel4.Text = $"时间：{datestr}"
    Me.ToolStripStatusLabel3.Text = $"当前用户：{RealName} ({RoleName})"
End Sub

Private Sub SetMenuVisibility()
    Dim isAdmin As Boolean = RoleName = "管理者"
    系统管理ToolStripMenuItem.Visible = isAdmin
    数据录入ToolStripMenuItem.Visible = isAdmin
End Sub