如果选择组合框vb.net mysql，则文本框中的数据库值

Imports MySql.Data.MySqlClient

Public Class Form1
    Dim conn As MySqlConnection
    Dim cmd As MySqlCommand
    Dim reader As MySqlDataReader

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' 连接到MySQL数据库
        conn = New MySqlConnection("server=数据库服务器地址;user id=用户名;password=密码;database=数据库名")
        conn.Open()

        ' 添加选项到组合框
        ComboBox1.Items.Add("选项1")
        ComboBox1.Items.Add("选项2")
        ComboBox1.Items.Add("选项3")
    End Sub

    Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
        ' 获取所选选项的值
        Dim selectedValue As String = ComboBox1.SelectedItem.ToString()

        ' 查询数据库并获取对应的值
        Dim query As String = "SELECT value FROM 表名 WHERE option = @option"
        cmd = New MySqlCommand(query, conn)
        cmd.Parameters.AddWithValue("@option", selectedValue)
        reader = cmd.ExecuteReader()

        If reader.Read() Then
            ' 将值赋给文本框
            TextBox1.Text = reader("value").ToString()
        End If

        reader.Close()
    End Sub
End Class