如何保持列表框的选定项处于选中状态 [英] how to keep the selected item of listbox selected

问题描述

我有一个列表框，其中三个列表项已经过硬编码.

Hi,
I have a listbox in which three list items have been hard coded.

<td align="justify">
                            <asp:ListBox ID="ListBox1" Width="200" SelectionMode="Multiple" runat="server" >
                            <asp:ListItem Text= "SP" Value= "1">
                            <asp:ListItem Text= "SC" Value= "2" >
                            <asp:ListItem Text= "TA" Value= "4" >       
                   
                           
                        </td>

我打算再次检查所选项目时保持选中状态(突出显示).
请指导如何完成.

I intend to keep the selected item selected(highlighted) when i check it again.
Please guide how can it be done.

推荐答案

<asp:ListItem Text="SP" Value= "1" Selected="true" ></asp:ListItem>

更新:

离开页面之前，您可以将所选值存储在会话中.

Update :

Before leaving the page, you can store your selected value in a Session.

Session["SelectedListItem"] = ListBox1.SelectedValue;

在您的PageLoad上，您可以检查Session["SelectedListItem"]是否具有值并进行设置.

And on your PageLoad, you can check the Session["SelectedListItem"] if it has value and set it.

if (Session["SelectedListItem"] != null) {
   ListBox1.SelectedValue = (string)Session["SelectedListItem"];
}

我不是ASPX专家，但是...我认为您需要将信息存储在会话中，并在此页面的Page_Load处理程序中设置适当的项目再次选择.请记住，默认情况下，HTTP是无状态的，因此每次访问该页面都是一次新访问，除非您编写一些会话代码来记住事情.

I''m not an ASPX expert but ... I think you will need to store the information in the session, and in your Page_Load handler for this page, set the appropriate items to be selected again. Remember that HTTP is by default stateless and so each visit to the page is a new visit, unless you write some session code to remember things.

ListBox.Items.Add(New ListItem("Select ListBox Type", ""))
        ListBox.DataSource = object
        ListBox.DataValueField = "TextField"
        ListBox.DataTextField = "ValueField"
        ListBox.DataBind()
        ListBox.SelectedIndex = 0

在这里它默认显示为选择列表框类型"，bcz的SelectedIndex设置为ZERO(0).
您可以根据需要进行更改.

Here it Shows by Default selection as "Select ListBox Type" bcz it''s SelectedIndex is set to ZERO(0).
You can change as per your requirement.

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