所选索引的组合框值减少已更改 [英] combo box value decrements on selected index changed

问题描述

HI全部，



我正在开发Window应用程序..我有一个组合框，其值为0,3,7,20 ...我加载来自Datatable的组合框，如下面的代码;

HI All,

I am working on Window application..I have a combo box with values like 0,3,7 ,20...I load the combo box from the Datatable like the code below;

Dim m_dtDelayedDeliveryDays As New DataTable
       m_dtDelayedDeliveryDays = GetDelayedDeliveryDays()


       For Each dr As DataRow In m_dtDelayedDeliveryDays.Rows
           Me.cmbDelayedDeliveryDays.Items.Add(dr("DeliveryDelayDays"))
       Next
       cmbDelayedDeliveryDays.DataSource = m_dtDelayedDeliveryDays
       cmbDelayedDeliveryDays.DisplayMember = "DeliveryDelayDays"
       cmbDelayedDeliveryDays.ValueMember = "DeliveryDelayDaysID"
       cmbDelayedDeliveryDays.SelectedIndex = -1

这很好..当所选索引发生变化时说例如我选择20它会自动更改为0 ...这是我在选择的索引中所做的更改：

This works fine..When the selected index gets changed say for example i select 20 it automatically changes to 0...Here is wat i do in Selected index changed:

Private Sub cmbDelayedDeliveryDays_SelectedIndexChanged(sender As System.Object, e As System.EventArgs) Handles cmbDelayedDeliveryDays.SelectedIndexChanged
        If cmbDelayedDeliveryDays.SelectedIndex > 0 Then

            Dim selectedDataRow As DataRow = DirectCast(cmbDelayedDeliveryDays.SelectedItem, DataRowView).Row


            Dim delayId As Integer = Convert.ToInt32(selectedDataRow("DeliveryDelayDaysID"))


            UpdateMerchant()

        End If


    End Sub

请帮我解决这个问题...当我检索表单时，我会收到表单，我将数据库中的值分配给组合框，如下所示：

Please help me with this...When i retrieve the form i get the form i assign the combo box the value from the database like this:

Dim delayid As Integer = .DeliveryDelayDaysID
           Dim m_dtDelayedDeliveryDays As New DataTable
           m_dtDelayedDeliveryDays = GetDelayedDeliveryDays()
           Dim str As Integer
           For Each drow As DataRow In m_dtDelayedDeliveryDays.Rows
               If drow("DeliveryDelayDaysID").Equals(delayid) Then
                   str = drow("DeliveryDelayDays")
                   cmbDelayedDeliveryDays.Text = str
               End If

           Next

我哪里错了..请帮助。谢谢。

Where am i going wrong..Please help.Thanks.

推荐答案

您在下面的代码中将SelectedValue指定为-1，因为它正在分配默认值，即零：

You are assigning the SelectedValue as -1 in the below code, due to which it is assigning the default value, which is zero:

cmbDelayedDeliveryDays.DataSource = m_dtDelayedDeliveryDays
       cmbDelayedDeliveryDays.DisplayMember = "DeliveryDelayDays"
       cmbDelayedDeliveryDays.ValueMember = "DeliveryDelayDaysID"

cmbDelayedDeliveryDays.SelectedIndex = -1 //评论此行并再次检查。



希望这可以解决您的问题...



如果有任何疑问，请告诉我。

cmbDelayedDeliveryDays.SelectedIndex = -1 //Comment this line and check again.

Hope this solve your issue...

If any queries do let me know.

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