Question

在组合框中选择和项目，如iphone5，samsung s3，htc等。如果用户选择Iphone5，则所选项目的描述将添加到文本框中。

似乎无法正常工作，因为每次我选择不同的项目时，它都会显示仅分配给iphone5的说明。

    If cboBrand.Items.Contains("Iphone5") = True Then

         TxtBox1.Text = "OS : iOS 6, upgradable to iOS 6.1, Chipset: Apple A6, CPU: Dual-core 1.2 GHz"

    ElseIf cboBrand.Items.Contains("Sumsung s3") = True Then

        TxtBox1.Text = "Os: Android OS, (Ice Cream Sandwich), upgradeable to 4.1.2 (Jelly Bean, CPU: Quad-core 1.4 GHz Cortex-A9)"

    End If

Answer 1

这将有效...而且它总是显示iphone 5的唯一原因是因为你的组合框总是包含这个，这意味着它总是如此......

  Private Sub cboBrand_SelectedIndexChanged(sender As Object, e As System.EventArgs) Handles cboBrand.SelectedIndexChanged

    If cboBrand.SelectedItem = ("Iphone5") Then

        txtAddress.Text = "OS : iOS 6, upgradable to iOS 6.1, Chipset: Apple A6, CPU: Dual-core 1.2 GHz"

    ElseIf cboBrand.SelectedItem = ("Sumsung s3") Then

        TextBox1.Text = "Os: Android OS, (Ice Cream Sandwich), upgradeable to 4.1.2 (Jelly Bean, CPU: Quad-core 1.4 GHz Cortex-A9)"

    End If
  End Sub

Answer 2

这里有一个比这更好的例子，特别是如果你还有更多要添加...请改用case语句并事先声明你的字符串......

  Private Sub cboBrand_SelectedIndexChanged(sender As Object, e As System.EventArgs) Handles cboBrand.SelectedIndexChanged

    Dim strIphone5 As String = "OS : iOS 6, upgradable to iOS 6.1, Chipset: Apple A6, CPU: Dual-core 1.2 GHz"
    Dim strSumPhone As String = "Os: Android OS, (Ice Cream Sandwich), upgradeable to 4.1.2 (Jelly Bean, CPU: Quad-core 1.4 GHz Cortex-A9)"

    Select Case cboBrand.SelectedItem

        Case "iphone5"
            txtAddress.Text = strIphone5
        Case "Sumsung s3"
            TextBox1.Text = strSumPhone

    End Select

  End Sub

现在如果您复制并粘贴它，请转到此子句的末尾并将其添加到它的末尾（如果它不存在...）

 Handles cboBrand.SelectedIndexChanged 'Sometimes when copied it looses its handlers..

组合框项目更改时无法更改文本

2 个答案: