在文本框中选择日期时如何启用下拉列表

问题描述：

当日期放在下拉列表上方的文本框中时，如何启用(原因:Dropdownlist).如果您知道

How to enable( Reason:Dropdownlist )when date is put in text box present above the drop down list .kindly post the code if u know

答

一个方法是使用 textchanged事件 [ ^ ]，并检查用户是否使用输入了有效日期datetime-tryparse [ ^ ]方法.然后启用下拉列表.
您可以使用已启用属性启用下拉列表[^ ]
例如:yourDropdownID.Enabled ="True";

One approach would be to use the textchanged event[^] of the textbox and check if the user has entered a valid date using datetime-tryparse[^] method. Then enable the dropdownlist.
You can enable the dropdownlist by using the Enabled property[^]
ex: yourDropdownID.Enabled = "True";

设置文本框的Autopostback属性为true

Set Autopostback property of textbox true

protected void TextBox1_TextChanged(object sender, EventArgs e)
{
   DateTime date1;
   if (DateTime.TryParse(dateString, out dateValue))
        dropdownlist1.Enabled=true;
   else
        dropdownlist1.Enabled=false;
}

Default.aspx页面代码.

Default.aspx page Code.

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="page2.aspx.cs" Inherits="Default.aspx" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>DropDown Demo with Textbox</title>

</head>
<body>
    <form id="form1" runat="server">
    <div>
    <asp:DropDownList ID="DropDownList1" style="Width:120px" runat="server"

            Enabled="False">
    <asp:ListItem>santosh_k</asp:ListItem>
    <asp:ListItem>Amit_K</asp:ListItem>
    </asp:DropDownList>
    </div>
    <div>Choose Date:
    <asp:TextBox ID="txtDate"  style="margin-top:50px"  runat="server"></asp:TextBox>
        <asp:Calendar ID="Calendar1" runat="server"

            onselectionchanged="Calendar1_SelectionChanged1"></asp:Calendar>
    </div>
    <div>

    </div>
    </form>
</body>
</html>

Default.aspx.cs背后的代码

Default.aspx.cs Code Behind

protected void Calendar1_SelectionChanged1(object sender, EventArgs e)
   {
       txtDate.Text = Calendar1.SelectedDate.ToString();
       DropDownList1.Enabled = true;
   }

在文本框中选择日期时如何启用下拉列表

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