Question

我有一个aspx网站，其中一个数组在名为Private Input（10）的inherits子句之后在页面顶部声明为String，它从Private strCalculation获取其值为String。当我单击存储按钮时，第一个数组值接收strCalculation值，然后数组槽增加1。但是，页面不保留strCalculation，因为我刚刚将减法按钮显示在标签中并且没有值！这是代码，首先发生减法方程，其中strCalculation得到它的值：

Option Strict On
Partial Class Index

Inherits System.Web.UI.Page

Private i As Integer = 0
Private Input(10) As String
Private strCalculation As String

Protected Sub btnSubtract_Click(sender As Object, e As EventArgs) Handles btnSubtract.Click
    lblMessage.Text = String.Empty
    Dim Numfirst As Double
    Double.TryParse(txtFirstNum.Text, Numfirst)
    Dim Numsecond As Double
    Double.TryParse(txtSecondNum.Text, Numsecond)
    Dim answer = Convert.ToString(Numfirst - Numsecond)
    strCalculation = (Numfirst & " - " & Numsecond & " = " & answer)
    txtResults.Text = strCalculation
    txtResults.Focus()
End Sub

Protected Sub btnStore_Click(sender As Object, e As EventArgs) Handles btnStore.Click
    Input(i) = strCalculation
    i += 1
End Sub

Answer 1

由于页面的生命周期很短（每个请求），您的数组将不会保留。将它保存到会话中：

'Is this the firt input?
If Session("InputCount") Is Nothing OrElse Session("InputCount") = "" Then
    Session("InputCount") = "0"
End If

'Set the new value.
Dim intInputCount As Integer = Convert.ToInt32(Session("InputCount")) + 1
Session("Input" + intInputCount.ToString()) = strCalculation

'Increment the input count.
Session("InputCount") = intInputCount.ToString()

然后引用存储的输入：

If Not Session("InputCount") Is Nothing OrElse Session("InputCount") <> "" Then

    Dim intRecordCount  = Convert.ToInt32(Session("InputCount"))

    For intCursor As Integer = 1 To intRecordCount

        Dim strCalculation As String = Session("Input" & intCursor.ToString())
        'Do Something with the value.   

    Next

End If

单击aspx按钮不会将变量值保存到数组

1 个答案: