我在单击按钮时验证下拉 asp 控件时遇到问题。我有一个面板,其中包含单选按钮、文本框、下拉菜单和保存按钮。如果选择了 zip 的单选按钮,则会出现一个下拉列表(与后面代码中的数据绑定),您必须从列表中选择一个 zip。我无法验证单击保存按钮的按钮是否从下拉列表中进行了选择。我想用 jQuery 来做,并尝试这样做,这样会弹出并提醒但它不起作用。喜欢让它在按钮的 onClick 之前验证选择。
<script type="text/javascript">
$(document).ready(function() {
$('#btn_submit').click(function() {
if ($('#ZIPDD').val() > 0) {
return true;
}
else {
alert('Please select a zip.');
return false;
}
});
});
<asp:UpdatePanel runat="server" ID="UP6" ChildrenAsTriggers="false" UpdateMode="conditional">
<ContentTemplate>
<table style="text-align:center;" cellpadding="5px">
<tr>
<td>
<table runat="server" id="_table" width="100%" cellspacing="10">
<tr>
<td style="width:100px; font-weight:bold; padding-bottom:inherit;" valign="middle">
<div>STEP 1:</div>
<div>Enter a #</div>
</td>
<td align="left" valign="middle" style=" margin-bottom:15px;">
<asp:TextBox runat="server" ID="txt_nbr" Width="70px"/>
<asp:Button ID="Button1" Text="Continue" runat="server" OnClick="Button1_Click"/>
</td>
</tr>
<tr>
<td style="width:100px; font-weight:bold; margin-bottom:15px;" valign="middle">
</td>
<td style="border:2px solid gray; background-color:Silver;">
<table runat="server" id="SHTable" visible="false" width="100%">
<tr align="left">
<th style="font-weight:bold;border-bottom:2px solid black;">Methods</th>
<th style="font-weight:bold;border-bottom:2px solid black;">Location</th>
<th style="font-weight:bold;border-bottom:2px solid black;"> <asp:Label runat="server" ID="DOTEXT"></asp:Label></th>
</tr>
<tr align="left">
<td>
<div style="margin-bottom:10px;"><asp:CheckBox runat="server" ID="ZIP" Text="ZIP" AutoPostBack="true" OnCheckedChanged="ZIP_CheckedChanged" /></div>
</td>
<td style="width:300px;">
<asp:DropDownList runat="server" ID="ZIPDD" Visible="false"/><br /><asp:Label ID="ziplabel" Visible="false" runat="server" style="color: red; font-size:12px;"/>
</td>
</tr>
</table>
</td>
</tr>
<tr>
<td style="width:100px; font-weight:bold; margin-bottom:15px;" valign="middle">
<div>Confirm changes and hit save</div>
</td>
<td align="left" valign="middle">
<asp:Button Text="Save" runat="server" ID="btn_submit" OnClick="btn_submit_Click" />
</td>
</tr>
</table>
</td>
</tr>
</table>
</ContentTemplate>
绑定到页面加载后代码中的下拉列表
protected void Page_Load(object sender, EventArgs e)
{
if (ZIPDD.Items.Count == 0)
{
Loadzips();
}
}
private void LoadBranches()
{
using (SqlConnection SQLCONN)
{
SQLCONN.Open();
SqlCommand SQLCOMM = SQLCONN.CreateCommand();
SQLCOMM.CommandText = "SELECT * FROM table";
IDataReader dr = SQLCOMM.ExecuteReader();
ZIPDD.DataSource = dr;
ZIPDD.DataValueField = "ZIPID";
ZIPDD.DataTextField = "ZIPLABEL";
ZIPDD.DataBind();
ZIPDD.Items.Insert(0, new ListItem(String.Empty, String.Empty));
ZIPDD.SelectedIndex = 0;
}
}