asp.net更新數據庫從下拉列表

Question

我試圖讓用戶選擇他們的婚姻狀況，將更新數據庫中的字段。這是用戶第一次使用時的情況，但如果他們想再次更新它，則不會更新。

如果我選擇一個數據源，如果他們想要更新，那麼在第一次選擇DDL時不會給出其他選項。

*ASPX*

<asp:DropDownList ID="DDLMarital" runat="server" TabIndex="1"> 
       <asp:ListItem Value = "Single" Text = "Single">Single</asp:ListItem> 
       <asp:ListItem Value = "Married" Text = "Married">Married</asp:ListItem> 
       <asp:ListItem Value = "Separated" Text = "Separated">Separated</asp:ListItem> 
       <asp:ListItem Value = "Divorced" Text = "Divorced">Divorced</asp:ListItem> 
      </asp:DropDownList> 

** * *ASPX.VB* ****

'binding... 

保護小組的Page_Load（發送者爲對象，例如作爲System.EventArgs）把手Me.Load

Dim dvSql4 As DataView = 
DirectCast(SqlMarital.Select(DataSourceSelectArguments.Empty), DataView) 
    For Each drvSql4 As DataRowView In dvSql4 
     DDLMarital.Text = drvSql4("Marital_Status").ToString() 
    Next 

結束子

「更新數據庫時， 「下一步」 按鈕是點擊 Protected Sub BtnNext_Click（sender As Object，e As System.EventArgs）Handle BtnNext.Click

Dim con As New SqlConnection 
    Dim cmd As New SqlCommand 

    con.ConnectionString = "Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\scrummingit2.mdf;Integrated Security=True;User Instance=True" 
    con.Open() 

    cmd.Connection = con 
    cmd.CommandText = ("UPDATE Student_Personal_Details SET Marital_Status = @Marital WHERE Student_No = @StudentNo") 

    Dim maritalParam As New SqlParameter("@Marital", DDLMarital.Text) 
    Dim studentNoParam As New SqlParameter("@StudentNo", lblEnrolmentStudentNumber.Text) 

    lblEnrolmentStudentNumber.Text = Session("Student") 

    cmd.Parameters.Add(maritalParam) 
    cmd.Parameters.Add(studentNoParam) 

    cmd.ExecuteNonQuery() 

    con.Close() 

End Sub

任何人都可以幫忙嗎？在谷歌沒有找到任何答案的日子裏，現在變得絕望了。

Answer 1

您應該檢查PostBack，並且只有當它不是回發時才分配選定的值。

Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load 
    If Not IsPostBack 
     Dim dvSql4 As DataView = 
    DirectCast(SqlMarital.Select(DataSourceSelectArguments.Empty), DataView) 
     For Each drvSql4 As DataRowView In dvSql4 
      DDLMarital.Text = drvSql4("Marital_Status").ToString() 
     Next 
    End If 
End Sub 

用戶的選擇是目前被忽略的價值獲得每個Load