在對機(jī)房收費(fèi)系統(tǒng)有了大致的認(rèn)識后，就開始做登錄窗體了。登錄窗體是最簡單的，但是我們需要先理清思路，最好是能畫一個簡單的流程圖，這樣就能理清邏輯，在敲代碼的時候就會非常簡單。

在這里需要注意以下幾點(diǎn)：

1.用戶輸入信息不能為空：

'查詢條件If Trim(txtUserName.Text = "") ThenMsgBox "用戶名稱不能為空，請重新輸入！", vbOKOnly + vbExclamation, "警告"txtUserName.SetFocusElseIf Trim(txtPassword.Text = "") ThenMsgBox "用戶密碼不能為空，請重新輸入！", vbOKOnly + vbExclamation, "警告"txtUserName.SetFocusEnd if

2.限制登錄次數(shù)：

'記載輸入密碼次數(shù)micount = micount + 1If micount = 1 ThenMsgBox "密碼輸入錯誤，您還有兩次機(jī)會！", 48, "警告"txtPassword.SetFocustxtPassword.Text = ""Exit SubElseIf micount = 2 ThenMsgBox "密碼輸入錯誤，您還有一次機(jī)會！", 48, "警告"txtPassword.SetFocustxtPassword.Text = ""Exit SubElseIf micount = 3 ThenMsgBox "密碼輸入錯誤，程序即將關(guān)閉！", 48, "警告"txtPassword.SetFocustxtPassword.Text = ""Me.HideExit SubEnd IfEnd If

3.限制特殊字符：

'限制特殊字符 Private Sub txtUserName_KeyPress(KeyAscii As Integer)Const a As String = "'!','@','#','$','%','^','&','*','(',')','<','>','?',':',' ','{','}','-','+','=','_','[',']',',','.','?','\','|','/',''','’'"KeyAscii = IIf(InStr(a, Chr(KeyAscii)), 0, KeyAscii) End Sub

4.限制不能復(fù)制粘貼

'不能復(fù)制粘貼 Private Sub txtPassword_KeyDown(KeyCode As Integer, Shift As Integer)If (KeyCode = 86 Or KeyCode = 67 Or KeyCode = 88) And Shift = 2 ThenMsgBox "不能粘貼復(fù)制", vbOKOnly + vbExclamation, "警告"txtPassword.Text = ""End If End Sub

5.限制登錄權(quán)限：

'權(quán)限限制If Trim(mrc.Fields(1)) = "一般用戶" ThenfrmMain.GeneralUser.Enabled = TruefrmMain.Operator.Enabled = FalsefrmMain.Operator.Visible = FalsefrmMain.Administrator.Enabled = FalsefrmMain.Administrator.Visible = FalseEnd IfIf Trim(mrc.Fields(1)) = "操作員" ThenfrmMain.GeneralUser.Enabled = TruefrmMain.Operator.Enabled = TruefrmMain.Administrator.Enabled = FalsefrmMain.Administrator.Visible = FalseEnd IfIf Trim(mrc.Fields(1)) = "管理員" ThenfrmMain.GeneralUser.Enabled = TruefrmMain.Operator.Enabled = TruefrmMain.Administrator.Enabled = TruefrmMain.Administrator.Visible = TrueEnd If

?

總結(jié)

以上是生活随笔為你收集整理的机房收费系统--登录窗体的全部內(nèi)容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網(wǎng)站內(nèi)容還不錯，歡迎將生活随笔推薦給好友。