机房收费系统--登录窗体

迷南。 2022-01-30 05:11 326阅读 0赞

在对机房收费系统有了大致的认识后，就开始做登录窗体了。登录窗体是最简单的，但是我们需要先理清思路，最好是能画一个简单的流程图，这样就能理清逻辑，在敲代码的时候就会非常简单。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM5MDcxNTk5_size_16_color_FFFFFF_t_70][]

在这里需要注意以下几点：

1.用户输入信息不能为空：

'查询条件
        If Trim(txtUserName.Text = "") Then
            MsgBox "用户名称不能为空，请重新输入！", vbOKOnly + vbExclamation, "警告"
            txtUserName.SetFocus
        ElseIf Trim(txtPassword.Text = "") Then
            MsgBox "用户密码不能为空，请重新输入！", vbOKOnly + vbExclamation, "警告"
            txtUserName.SetFocus
        End if

2.限制登录次数：

'记载输入密码次数
           micount = micount + 1
        If micount = 1 Then
            MsgBox "密码输入错误，您还有两次机会！", 48, "警告"
            txtPassword.SetFocus
            txtPassword.Text = ""
            Exit Sub
        ElseIf micount = 2 Then
            MsgBox "密码输入错误，您还有一次机会！", 48, "警告"
            txtPassword.SetFocus
            txtPassword.Text = ""
            Exit Sub
        ElseIf micount = 3 Then
            MsgBox "密码输入错误，程序即将关闭！", 48, "警告"
            txtPassword.SetFocus
            txtPassword.Text = ""
            Me.Hide
            Exit Sub
        End If
        End 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.限制不能复制粘贴

'不能复制粘贴
    Private Sub txtPassword_KeyDown(KeyCode As Integer, Shift As Integer)
        If (KeyCode = 86 Or KeyCode = 67 Or KeyCode = 88) And Shift = 2 Then
            MsgBox "不能粘贴复制", vbOKOnly + vbExclamation, "警告"
            txtPassword.Text = ""
        End If
    End Sub

5.限制登录权限：

'权限限制
        If Trim(mrc.Fields(1)) = "一般用户" Then
            frmMain.GeneralUser.Enabled = True
            frmMain.Operator.Enabled = False
            frmMain.Operator.Visible = False
            frmMain.Administrator.Enabled = False
            frmMain.Administrator.Visible = False
        End If
                    
        If Trim(mrc.Fields(1)) = "操作员" Then
            frmMain.GeneralUser.Enabled = True
            frmMain.Operator.Enabled = True
            frmMain.Administrator.Enabled = False
            frmMain.Administrator.Visible = False
        End If
    
        If Trim(mrc.Fields(1)) = "管理员" Then
            frmMain.GeneralUser.Enabled = True
            frmMain.Operator.Enabled = True
            frmMain.Administrator.Enabled = True
            frmMain.Administrator.Visible = True
        End If

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM5MDcxNTk5_size_16_color_FFFFFF_t_70]: /images/20220130/1de63e68803847c1b607ee172ff2c71c.png