Html 将 HTML5 占位符文本添加到文本框 .net
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Add HTML5 placeholder text to a textbox .net
提问by tiffylou
I have a standard input:
我有一个标准输入：
<asp:TextBox type="text" runat="server" id="txtSearchTerm" />
I'd like to have this render with a dynamic HTML5 placeholder. Something like:
我想使用动态HTML5 placeholder 进行渲染。就像是：
'Code Behind
txtSearchTerm.**placeholder** = "Search " + Site.Name
So that it outputs the following HTML:
以便它输出以下 HTML：
<input type="text" runat="server" id="txtSearchTerm"
placeholder="Search Site #1" />
where Site.Name = "Site #1".
其中 Site.Name = "Site #1"。
txtSearchTerm.placeholderis not a property. I have it set to text and then run javascript to show/hide on focus BUT I would much rather just use the HTML5 placeholder value. How can I render this?
txt搜索词。占位符不是属性。我将它设置为文本，然后运行 javascript 来显示/隐藏焦点，但我宁愿只使用 HTML5 占位符值。我怎样才能呈现这个？
Please no JS/client side solutions.
请不要使用 JS/客户端解决方案。
回答by Steven V
You could use the Attributescollection. So you would have something like
您可以使用该Attributes集合。所以你会有类似的东西
txtSearchTerm.Attributes.Add("placeholder", "Search" + Site.Name);
or
或者
txtSearchTerm.Attributes["placeholder"] = "Search" + Site.Name; // or Attributes("placeholder") if you're using vb.net
And if you're using resources for localization/translation:
如果您使用资源进行本地化/翻译：
txtSearchTerm.Attributes["placeholder"] = GetLocalResourceObject("YourLocalResourceName").ToString();
回答by Tony
Because I find it annoying/tiresome to add all the placeholders from the code behind. You can create a new TextBox Class that inherits the WebControls TextBox and then you can add the placeholder from the CodeBehind or from the HTML Side.
因为我觉得从后面的代码中添加所有占位符很烦人/令人厌烦。您可以创建一个新的 TextBox 类来继承 WebControls TextBox，然后您可以从 CodeBehind 或 HTML 端添加占位符。
TextBox.cs (Placed in Project/Controls/)
TextBox.cs（放置在 Project/Controls/ 中）
namespace Project.Controls
{
public class TextBox : System.Web.UI.WebControls.TextBox
{
public string PlaceHolder { get; set; }
protected override void OnLoad(EventArgs e)
{
if(!string.IsNullOrWhiteSpace(PlaceHolder))
this.Attributes.Add("placeholder", PlaceHolder);
base.OnLoad(e);
}
}
}
Register Control In the Web.Config:
在 Web.Config 中注册控件：
<system.web>
<pages>
<controls>
<add tagPrefix="ext" assembly="Project" namespace="Project.Controls" />
</controls>
</pages>
</system.web>
(use whatever tag prefix you want)
（使用任何你想要的标签前缀）
Usage:
用法：
<ext:TextBox runat="server" id="SomeId" PlaceHolder="This is a PlaceHolder" />
or from the code behind
或从背后的代码
SomeId.PlaceHolder="This is a PlaceHolder";
回答by RonaldPaguay
I just put placeholder property in HTML code and works:
我只是将占位符属性放在 HTML 代码中并起作用：
<asp:TextBox placeholder="hola mundo" ID="some_id" runat="server"/>
回答by mason
There is also the TextBoxWatermark extender included in Microsoft's Ajax Control toolkit. It's not HTML5, but it's backwards compatible (I believe). http://www.asp.net/AjaxLibrary/AjaxControlToolkitSampleSite/TextBoxWatermark/TextBoxWatermark.aspx
Microsoft 的 Ajax Control 工具包中还包含 TextBoxWatermark 扩展器。它不是 HTML5，但它向后兼容（我相信）。 http://www.asp.net/AjaxLibrary/AjaxControlToolkitSampleSite/TextBoxWatermark/TextBoxWatermark.aspx
<ajaxToolkit:TextBoxWatermarkExtender ID="TBWE2" runat="server"
TargetControlID="TextBox1"
WatermarkText="Type First Name Here"
WatermarkCssClass="watermarked" />
