類別的應用

類別Class就是物件的應用，建立一個類別檔之後，就能在程式內宣告成變數物件。

類別檔：ClassConAdtp

'類別(物件)屬性 Property

Public ErrOccur As Boolean '執行錯誤

Public ErrMsg As String '錯誤訊息

'新增、修改、刪除，都是類別(物件)裡的方法

 '新增

    Sub insert(ByVal strSQL As String)

        Dim con As SqlClient.SqlConnection = New SqlClient.SqlConnection(DBSchoolcnStr)

        Dim adtp As SqlClient.SqlDataAdapter = New SqlClient.SqlDataAdapter

        Try

            con.Open()

           adtp.InsertCommand = New SqlClient.SqlCommand(strSQL, con)

            adtp.InsertCommand.ExecuteNonQuery()

            con.Close()

            ErrOccur = False

            ErrMsg = ""

        Catch ex As Exception

            ErrOccur = True

            ErrMsg = ex.Message

        End Try

    End Sub

'修改

    Sub update(ByVal strSQL As String)

        Dim con As SqlClient.SqlConnection = New SqlClient.SqlConnection(DBSchoolcnStr)

        Dim adtp As SqlClient.SqlDataAdapter = New SqlClient.SqlDataAdapter

        Try

            con.Open()

            adtp.UpdateCommand = New SqlClient.SqlCommand(strSQL, con)

           adtp.UpdateCommand.ExecuteNonQuery()

            con.Close()

            ErrOccur = False

            ErrMsg = ""

        Catch ex As Exception

            ErrOccur = True

            ErrMsg = ex.Message

        End Try

    End Sub

'刪除

Sub delete(ByVal strSQL As String)

        Dim con As SqlClient.SqlConnection = New SqlClient.SqlConnection(DBSchoolcnStr)

        Dim adtp As SqlClient.SqlDataAdapter = New SqlClient.SqlDataAdapter

        Try

            con.Open()

            adtp.DeleteCommand = New SqlClient.SqlCommand(strSQL, con)

            adtp.DeleteCommand.ExecuteNonQuery()

            con.Close()

            ErrOccur = False

            ErrMsg = ""

        Catch ex As Exception

            ErrOccur = True

            ErrMsg = ex.Message

        End Try

    End Sub

'程式內宣告

Dim obj As New ClassConAdtp

obj.insert("insert into ...")

obj.update("update ... set ... where ...")

obj.delete("delete from ... where ...")