在标签上显示文本框数量 [英] Displaying text box count on a label

问题描述

大家好，
我有一个ASP文本框和一个标签，用于按如下方式显示字符数:

Hi all,
I have a asp text box and a label to display the count of characters as so:

<asp:TextBox ID="txtSignature" runat="server" TextMode = "MultiLine"

                   MaxLength="160" ></asp:TextBox>   <asp:Label ID="lblCharacters" runat="server"></asp:Label>

我已经放入Jscript函数来显示计数:

i have put in Jscript functions to display the count:

<script  language ="javascript" type="text/javascript">
    function DisplayCount() {
        var length = document.getElementByID('<%= txtSignature.ClientID %>').value.length;
        document.getElementByID('<%= lblCharacters %>').value = length;
        alert(length);
    }
</script>

页面加载事件具有以下代码:

The page load event has the following code:

txtSignature .Attributes.Add("javascript:onkeydown();",  "javascript:return DisplayCount();");
txtSignature.Attributes.Add("javascript:onkeypress();", "javascript:return DisplayCount();");

当我在文本框中键入内容时，我仍然看不到标签上的字数.有人知道概率是多少吗?
谢谢.

I still cant see teh count on teh label when i type in the textbox. Any one knows what the prob might be?
Thanks.

推荐答案

只需将您的JavaScript代码替换为此.

Just replace your javascript code with this.

<script language="javascript" type="text/javascript">
    function DisplayCount() {
        var length = document.getElementById(''<%=txtSignature.ClientID%>'').value.length;
        document.getElementById(''<%=lblCharacters.ClientID%>'').innerText = length;
        alert(length);
    }
    </script>

1)将 D 替换为document.getElementByID中的 d .应该是document.getElementById
2)对于标签，您必须使用innerText 设置值.

并且在页面加载中还可以像这样更改代码.

1) Replace D with d in document.getElementByID. It should be document.getElementById
2) For label you have to use innerText to set the value.

And in page load also change the code like this.

txtSignature.Attributes.Add("onkeypress", "javascript:return DisplayCount();");

仅keypress 或keydown 就足够了.

Only keypress or keydown is enough.

document.getElementByID('<%= lblCharacters %>').innerHTML = length;
document.getElementByID('<%= lblCharacters %>').innertext = length;

我可以看到至少一个错误:必须为document.getElementById(大写).代码区分大小写，您知道...

—SA

I can see at least one bug: must be document.getElementById (capitalization). Code is case-sensitive, you know…

—SA

这篇关于在标签上显示文本框数量的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！