C# 如何在 ASP.NET 中禁用下拉列表？
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How can I disable a dropdownlist in ASP.NET?
提问by Yves
How can I disable a DropDownListin ASP.NET?
如何DropDownList在 ASP.NET 中禁用 a ？
Code:
代码：
<asp:TemplateField HeaderText="Effective Total Hours">
<ItemTemplate>
<%# Eval("TotalHoursEffect")%>
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList ID="ddlEditTotalHoursEffect" AppendDataBoundItems="true"
DataSourceID="dsTHMsql" DataValueField="Minutes" Enabled="false"
ReadOnly="true" DataTextField="Display"
SelectedValue='<%# Eval("TotalHoursEffect") %>' runat="server">
<asp:ListItem Selected="True" Value="">(Choose Minutes)</asp:ListItem>
</asp:DropDownList>
</EditItemTemplate>
</asp:TemplateField>
This is not working for me. What am I doing wrong?
这对我不起作用。我究竟做错了什么？
采纳答案by Nikki9696
There is no readonly property for a true dropdownlist for asp.net webforms.
asp.net webforms 的真正下拉列表没有只读属性。
<asp:DropDownList ID="DropDownList1" runat="server" Enabled="False">
</asp:DropDownList>
If that isn't what you're doing, you will need to be a lot more specific. You didn't ask a question, you didn't explain WHAT isn't working, or say if you're using webforms or winforms, or if it's in the code behind or the aspx page.
如果这不是你正在做的，你将需要更加具体。您没有提出问题，也没有解释什么不起作用，或者说您使用的是 webforms 还是 winforms，或者它是否在背后的代码或 aspx 页面中。
ETA: remove the readonly property from the dropdownlist, it isn't valid. AFTER you test that part and see if it fixed it, if it still isn't doing what you want, please tell us what it isn't doing. Is it not disabling? Is it not databinding? What's going on with it?
ETA：从下拉列表中删除只读属性，它无效。在您测试该部件并查看它是否修复后，如果它仍然没有按照您的要求运行，请告诉我们它没有做什么。不是禁用吗？不是数据绑定吗？这是怎么回事？
Oh, and make sure you use Bind, not Eval, for edit templates if the value is being passed back in any way such as to a query update. Sometimes the platform is doing it behind the scenes, so generally speaking, just use Bind.
哦，如果值以任何方式传回，例如查询更新，请确保使用 Bind 而不是 Eval 来编辑模板。有的时候是平台在幕后做的，所以一般来说用Bind就行了。
One more edit: this works for me in the most basic sense in that it binds and the dropdown is not selectable.
再一次编辑：这在最基本的意义上对我有用，因为它绑定并且下拉列表是不可选择的。
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="ProductID"
DataSourceID="sqldsProducts" AutoGenerateEditButton="True">
<Columns>
<asp:BoundField DataField="ProductID" HeaderText="ProductID" SortExpression="ProductID" />
<asp:TemplateField HeaderText="CategoryID" InsertVisible="False" SortExpression="CategoryID">
<EditItemTemplate>
<asp:DropDownList Enabled="false" ID="ddlCategory" runat="server" DataSourceID="sqldsCategories"
DataTextField="CategoryName" DataValueField="CategoryID" SelectedValue='<%# Bind("CategoryID") %>' AppendDataBoundItems="True">
<asp:ListItem Selected="True" Value="" Text="-- choose one --" />
</asp:DropDownList>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="lblCategory" runat="server" Text='<%# Bind("ProductID") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="ProductName" HeaderText="ProductName" SortExpression="ProductName" />
</Columns>
</asp:GridView>
回答by Yves
var rmu_minutes = 0;
var initRmuChangeHandlers = function() {
$(".container select").change(function(e) {
var x = 0;
var dropDowns = $(".container select");
dropDowns.each(function() {
var ddl = this;
x += parseInt(ddl.value);
if (!dayOffRmuValidator(x)) {
alert("4 Hours MAX");
ddl.selectedIndex = 0;
}
});
rmu_minutes = x;
updateTotalRmu();
});
}
var initClearRmuDropDowns = function() {
var dropDowns = $(".container select");
dropDowns.each(function() {
var ddl = this;
ddl.selectedIndex = 0;
});
}
var dayOffRmuValidator = function(rmu_minutes) {
var _MAXMINUTES = 240;
var ddl = $get('ctl00_ContentPlaceHolder1_DetailsView1_ddlEditType');
var ddlVal = parseInt(ddl.options[ddl.selectedIndex].value);
if (ddlVal == RequestTypes["Day Off"])
return rmu_minutes <= _MAXMINUTES;
return true;
}
var badRmuHours = function() {
alert("You are only allowed to make up 4 hours total for a day off");
var ddlTotal = $("#ctl00_ContentPlaceHolder1_DetailsView1_ddlEditTotalHoursEffect")[0];
ddlTotal.selectedIndex = 0;
}
回答by Mark Brittingham
This is what I do:
这就是我所做的：
ddlEditTotalHoursEffect.Enabled=false;
ddlEditTotalHoursEffect.Enabled=false;
I can be done from your code-behind.
我可以从你的代码隐藏中完成。
Oh, wait, you have enabled equal to false. What is it you are looking to do, then? Do you want to make the data entry box enabled but not the pull-down?
哦，等等，您已启用等于 false。那你想做什么？您要启用数据输入框而不启用下拉菜单吗？
回答by Anjisan
You can disable a dropdownlist but you'll need to do it from the code behind.
您可以禁用下拉列表，但您需要从后面的代码中进行操作。
Try this in your .cs (assuming your asp:DropDownList as an id of ddlCategory),
在你的 .cs 中试试这个（假设你的 asp:DropDownList 作为 ddlCategory 的 id），
ddlCategory.Attributes.Add("disabled", "disabled");
回答by drs9222
Assuming that by disable you mean "make it so that the user can't select an item from the list" then the following examples all result in the same html (which works for me):
假设禁用您的意思是“使用户无法从列表中选择项目”，那么以下示例都会产生相同的 html（这对我有用）：
Method 1:
方法一：
<asp:DropDownList ID="dd" Enabled="false" runat="server">...
Method 2:
方法二：
<asp:DropDownList ID="dd" disabled="disabled" runat="server">...
Method 3(aspx):
方法3（aspx）：
<asp:DropDownList ID="dd" runat="server">...
Method 3(aspx.cs):
方法3（aspx.cs）：
dd.Enabled = false;
Method 4(aspx):
方法4（aspx）：
<asp:DropDownList ID="dd" runat="server">...
Method 4(aspx.cs):
方法4（aspx.cs）：
dd.Attributes.Add("disabled", "disabled")
Resulting HTML:
结果 HTML：
<select name="dd" id="dd" disabled="disabled">...
