在onkeypress事件中对数据列表项进行排序 [英] sorting datalist items on onkeypress event

问题描述

我有一个数据列表，上面有一个文本框.
而且我想做的是在文本框中输入一个字符时，只有与该字符相对应的项才应b填充到数据列表中.所有过程都应在文本框的onkeypress事件上进行

注意:数据列表中只有900个名称列表.

i have a datalist above which i have a textbox.
and what i want to do is as i enter a character in textbox, only items corresponding to that char should b filled in datalist.and all process should be on onkeypress event of textbox

NOTE: there is only 900 names list in datalist.

推荐答案

您必须使用自动回发或(更快的)ajax，如下所示:

You have to use autopostback, or (faster) ajax like this:

<asp:TextBox runat="server" ID="txtFilter" autocomplete="off" ></asp:TextBox>
<asp:LinkButton runat="server" ID="lbFilter" onclick="FilterDropdown" Text="filter" style="visibility:hidden;"></asp:LinkButton>
<asp:ScriptManager runat="server" ID="scrMang"></asp:ScriptManager>
<asp:UpdatePanel ID="updSelction" runat="server">
    <ContentTemplate>
        <asp:ListBox runat="server" ID="ddl" ></asp:ListBox>
    </ContentTemplate>
    <Triggers >
        <asp:AsyncPostBackTrigger ControlID="lbFilter" />
    </Triggers>
</asp:UpdatePanel>

public partial class _Default : System.Web.UI.Page
{
    string[] Names = {"Andreas",
                     "Benjamin",
                     "Caroline",
                     "Daniel",
                     "Emil",
                     "Franziska",
                     "Gustav",
                     "Hans"
                     };
    protected void Page_Load(object sender, EventArgs e)
    {
        txtFilter.Attributes.Add("onkeyup", "__doPostBack('" + lbFilter.UniqueID + "','');");
        if(!IsPostBack) {
            foreach(var name in Names) {
                ddl.Items.Add(name);
            }
        }
    }

    protected void FilterDropdown(object sender, EventArgs e) {
        ddl.Items.Clear();
        foreach(var name in Names) {
            if(name.ToLower().Contains(txtFilter.Text.ToLower())) {
                ddl.Items.Add(name);
            }
        }
        txtFilter.Focus();
        if(ddl.Items.Count >0)
        ddl.Items[0].Selected = true;
    }
}

如果您知道如何使用LINQ，则可以只编写几行代码并获得所需的结果:

If you know how to use LINQ then you can write only a couple of lines of code and achieve the desired outcome:

private void textBox1_TextChanged(object sender, EventArgs e)
        {
            string search = textBox1.Text;
            listBox1.DataSource = (from l in list where l.Contains(search) select l).ToList();
        }

列表"只是在构造函数中定义并填充的简单字符串列表.尝试一下并尝试一下.

干杯...

如果您还不了解LINQ，这是一个不错的开始， http://msdn.microsoft .com/en-us/netframework/aa904594 [ ^ ]

使用

"list" is just a simple list of strings defined in the constructor and populated. Try it and hack around with it.

Cheers...

here is a good start for LINQ if you don''t already know it, http://msdn.microsoft.com/en-us/netframework/aa904594[^]

use

l.StartsWith(search)

而不是

l.Contains(search)

进行野外搜索. StartsWith搜索更准确的字符串开头.

which does a wild search. StartsWith searches for the beginning of the string which is more accurate.

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