在表单中调用模块和类 [英] Calling a Module and a Class within a Form

问题描述

我有一个 Employee 类，我在其中调用我的数据库连接模块进行查询.

I have an Employee class where I call my database connection Module to make a query.

我收到编译错误:预期的函数或变量"，我不明白，因为我在表单顶部设置了 empObj.

I am getting "Compile Error: Expected function or variable", which I'm not understanding, because I have the empObj set at the top of the form.

我想从 Employee.getEmployee 方法返回值.有人可以告诉我如何从我的表单中调用 Employee 类吗?我必须先导入课程吗?我不相信 VB6 支持 Imports 关键字.

I would like to return the value from the Employee.getEmployee method. Can someone please show me how to call the Employee class from my form? Do I have to import the class first? I don't believe VB6 supports the Imports keyword.

这是我的表格:

Option Explicit

Private empObj As New Employee

Private Sub Form_Load()
  'For testing only
  MsgBox (empObj.getEmployee)
End Sub

这是我的课:

Public Sub getEmployee()
  'ConnectSQL is a database connection
  return ConnectSQL
End Sub

这是模块:

Public Function ConnectSQL()
  Set SQLMyconn = New ADODB.Connection
  Set SQLRecset = New ADODB.Recordset
  SQLMyconn.Open "Driver={MySQL ODBC Client Interface};ServerName=localhost;dbq=@testdb"
End Function

推荐答案

你想做的基本shell是这样的:

The basic shell of what you want to do is like this:

Option Explicit

Private empObj As Employee

Private Sub Form_Load()
   Set empObj = New Employee
   MsgBox empObj.getEmployee
End Sub

Public Function getEmployee() As String
   getEmployee = ConnectSQL
End Function

Public Function ConnectSQL() As String
   Set SQLMyconn = New ADODB.Connection
   Set SQLRecset = New ADODB.Recordset
   SQLMyconn.Open "Driver={MySQL ODBC Client Interface};ServerName=localhost;dbq=@testdb"

   ConnectSQL = "data from your DB lookup"
End Function

几乎每一行都与您发布的内容不同，因此请仔细查看代码.

Almost every line is different than what you posted, so carefully look at the code.

根据评论，这里是如何修改代码以返回连接对象:

Based on a comment, here's how to modify the code to return a connection object:

Option Explicit

Private empObj As Employee

Private Sub Form_Load()
   Set empObj = New Employee
   MsgBox empObj.getEmployee

   Dim MyConnection As ADODB.Connection
   Set MyConnection = ConnectSQL()

   'you can grab and use the connection in your form, too.
End Sub

Public Function getEmployee() As String
   Dim MyConnection As ADODB.Connection
   Set MyConnection = ConnectSQL()

   'use the connection to grab data

   getEmployee = "data from your DB lookup"
End Function

Public Function ConnectSQL() As ADODB.Connection
   Set ConnectSQL = New ADODB.Connection
   ConnectSQL.Open "Driver={MySQL ODBC Client Interface};ServerName=localhost;dbq=@testdb"
End Function

完成连接后不要忘记关闭连接.总结一下变化:

Don't forget to close your connection after you are done with it. To sum up the changes:

1. empObj - 您应该分别声明和实例化您的对象.
2. MsgBox - 不需要 ().
3. Functions vs Subs - 第一个返回数据，第二个不返回.确保声明函数的返回类型.
4. return - 此语句已过时，不能满足您的要求.相反，为函数的名称分配一个值.

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