1. 購物範例

2. 步驟一：建立UI
一個combobox + ㄧ個TextBox+ㄧ個Gridview 物件
二個Button物件

3. Form_Load ‘ 本表單全域物件 Dim dt As New DataTable("") dt.Columns.Add("產品編號")

4. 設定ComboBox

5. 設定ComboBox

6. 設定ComboBox

7. 設定ComboBox
Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged
p_id = ComboBox1.SelectedValue.ToString()
p_name = ComboBox1.Text
End Sub
Dim p_id, p_name As String
‘ 加入按鈕
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
dt.Rows.Add(New Object() {p_id, p_name, TextBox1.Text})
DataGridView1.DataSource = dt
End Sub

8. 確定購買 Dim i As Integer For i = 1 To DataGridView1.RowCount - 1
'DataGridView1.Rows(i - 1).Cells(0).Value.ToString()
' 一.connection物件
'1.宣告
Dim dbconn As OleDbConnection
'2.產生物件並給定參數
dbconn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=teacher.mdb;User Id=admin;Password=;")
dbconn.Open()
'二.command物件執行sql指令
Dim dbcmd As New OleDbCommand
'2.產生並執行sql指令
dbcmd.CommandType = CommandType.Text
dbcmd.CommandText = "insert into sales (c_id,p_id,amount,s_day) values (1," + DataGridView1.Rows(i - 1).Cells(0).Value + "," + DataGridView1.Rows(i - 1).Cells(2).Value + ",'" + System.DateTime.Today.ToString() + "')"
dbcmd.Connection = dbconn
dbcmd.ExecuteNonQuery()
dbconn.Close()
Next