前言

對機房系統有了巨集觀把控以後，可以開始登入窗體了。先別急著敲程式碼，先搞懂要滿足什麼功能。登入窗體要做到使用者能成功登入，並且有三種許可權的設定。瞭解了要滿足的功能，要對思路進行梳理，製作流程圖就可以幫我們很好的梳理思路。

部分程式碼展示

限制登入次數程式碼

miCount = miCount + 1
If miCount = 1 Then
    MsgBox "密碼輸入錯誤，您還有兩次機會！", 48, "警告"
    txtPassword.SetFocus
    txtPassword.Text = ""
    Exit Sub
Else
    If miCount = 2
 
 Then
        MsgBox "密碼輸入錯誤，您還有一次機會！", 48, "警告"
        txtPassword.SetFocus
        txtPassword.Text = ""
        Exit Sub
    Else
        If miCount = 3 Then
            MsgBox "密碼輸入錯誤，程式即將關閉！", 48, "警告"
            txtPassword.SetFocus
            txtPassword.Text = ""
            Me.Hide
            Exit
 
 Sub
        End If
    End If
End If

許可權限制程式碼

If Trim(mrc.Fields(2)) = "一般使用者" Then
   frmMain.userName.Enabled = True
   frmMain.opeMenu.Enabled = False
   frmMain.opeMenu.Visible = False
   frmMain.adminMenu.Enabled = False
   frmMain.adminMenu.Visible = False
End If

If Trim(mrc.Fields(2)) = "操作員"
 
 Then
    frmMain.userName.Enabled = True
    frmMain.opeMenu.Enabled = True
    frmMain.adminMenu.Enabled = False
    frmMain.adminMenu.Visible = False
End If

限制字元程式碼

Private Sub txtPassWord_KeyPress(KeyAscii As Integer)
    If KeyAscii > 31 And KeyAscii < 48 Or KeyAscii > 57 And KeyAscii < 65 Or KeyAscii > 90 And KeyAscii > 122 And KeyAscii < 127 Then
        MsgBox "不能輸入特殊字元！", 48, "警告"
        KeyAscii = 0
    End If
End Sub

Private Sub txtUserName_KeyPress(KeyAscii As Integer)
    If KeyAscii > 31 And KeyAscii < 48 Or KeyAscii > 57 And KeyAscii < 65 Or KeyAscii > 90 And KeyAscii > 122 And KeyAscii < 127 Then
        MsgBox "不能輸入特殊字元！", 48, "警告"
        KeyAscii = 0
    End If
End Sub

結語

登入窗體是比較容易的，雖然容易，還是先畫流程圖能讓思路更加清晰哦！如果你的方法能讓程式碼更少，歡迎交流！