Question

我是Visual Basic的新手，现在我将我的程序连接到数据库以保存并获取输入，并且工作正常。我现在想要做的是在其他表单上重用我与数据库的连接。我正在考虑接受全球宣言并把它们放到一个班级并让它们可以从那里访问，但我不知道该怎么做。我尝试了不同的方法，但我总是遇到一些错误...我真的被困住了，并且会感激我能得到的任何帮助。

以下是代码的一部分：

Imports MySql.Data.MySqlClient
Public Class Form1

    'GLOBAL DELARATION
    Dim conString As String = "Server=localhost;" & "Database=data;" & "Uid=password;" & "Pwd=password;"
    Dim con As New MySqlConnection(conString)
    Dim cmd As MySqlCommand
    Dim adapter As MySqlDataAdapter
    Dim dt As New DataTable()

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        'CONSTRUCT DATAGRID VIEW
        DataGridView1.ColumnCount = 4
        DataGridView1.Columns(0).Name = "ID"
        DataGridView1.Columns(1).Name = "Name"
        DataGridView1.Columns(2).Name = "Position"
        DataGridView1.Columns(3).Name = "TEAM"

        DataGridView1.SelectionMode = DataGridViewSelectionMode.FullRowSelect
        Retrieve()
    End Sub

    Private Sub cleartxt()
        TextBox_name.Text = ""
        TextBox_position.Text = ""
        TextBox_team.Text = ""

    End Sub

    'INSERT INTO DB
    Private Sub Add()
        Dim sql As String = "INSERT INTO people(Name,Position,Team) VALUES(@NAME,@POSITION,@TEAM)"
        cmd = New MySqlCommand(sql, con)

        'PARAMETERS
        cmd.Parameters.AddWithValue("@NAME", TextBox_name.Text)
        cmd.Parameters.AddWithValue("@POSITION", TextBox_position.Text)
        cmd.Parameters.AddWithValue("@TEAM", TextBox_team.Text)

        'Open Connection and INSERT
        Try
            con.Open()
            If cmd.ExecuteNonQuery() > 0 Then
                MsgBox("Produktet er lagt inn korrekt")
                cleartxt()
            End If
            con.Close()
            Retrieve()
        Catch ex As Exception

            MsgBox(ex.Message)
            con.Close()
        End Try
    End Sub

以其他形式重用VB Connection

0 个答案: