[英]Visual Basic how to stop an event after MsgBox is shown
我想确保用户在我的进一步处理之前检查了我的 3 个复选框之一,因此我在下面创建了 function 并在他们没有检查任何内容时生成一个 Msg。 问题是在消息框之后该过程仍在进行。 那么在显示这个特定的 msgbox 之后有什么方法可以阻止这个事件?
Private Sub btnPay_Click(sender As Object, e As EventArgs) Handles btnPay.Click
If chkbNotes.Checked = True Then
conn.Open()
sql = "UPDATE Order SET payment_method_id = 1 WHERE Id = '" + FoodMenu.OrderID + "';"
cmd = New SqlCommand(sql, conn)
cmd.ExecuteNonQuery()
Else
If chkbCreditCard.Checked = True Then
conn.Open()
sql = "UPDATE Order SET payment_method_id = 2 WHERE Id = '" + FoodMenu.OrderID + "';"
cmd = New SqlCommand(sql, conn)
cmd.ExecuteNonQuery()
Else
If chkbEwallet.Checked = True Then
conn.Open()
sql = "UPDATE Order SET payment_method_id = 2 WHERE Id = '" + FoodMenu.OrderID + "';"
cmd = New SqlCommand(sql, conn)
cmd.ExecuteNonQuery()
Else
MsgBox("Please choose 1 Payment Method", MsgBoxStyle.Exclamation, "Error")
End If
End If
End If
Dim Amount As String
Amount = InputBox("Enter Paying Amount (EX:100.00)", "Amount")
If (IsNumeric(Amount)) = True Then
.
.
.
这是您的代码应如下所示:
Private Sub btnPay_Click(sender As Object, e As EventArgs) Handles btnPay.Click
Dim paymentMethodId As Integer
If chkbNotes.Checked Then
paymentMethodId = 1
ElseIf chkbCreditCard.Checked Then
paymentMethodId = 2
ElseIf chkbEwallet.Checked Then
paymentMethodId = 3
Else
MessageBox.Show("Please choose 1 Payment Method", "Error", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
Return
End If
sql = "UPDATE Order SET payment_method_id = @PaymentMethodId WHERE Id = @Id"
cmd = New SqlCommand(sql, conn)
cmd.Parameters.Add("@PaymentMethodId", SqlDbType.Int).Value = paymentMethodId
cmd.Parameters.Add("@Id", SqlDbType.Int).Value = FoodMenu.OrderID
conn.Open()
cmd.ExecuteNonQuery()
我冒昧地假设 payemtn 方法 ID 在第三种情况下应该是 3,而不是您在原始代码中使用的 2。
我还建议更改您的 ADO.NEt 代码,因为您似乎正在重用连接和命令对象。 您应该在需要它们的时间和地点创建和销毁它们。
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