Javascript 从文本框中获取输入值
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Getting input values from text box
提问by Beanno1116
I'm trying to get the text from a text box.
我正在尝试从文本框中获取文本。
I have 2 input text boxes that are not in a form, and I'm trying to retrieve the valueand store it in a variable.
我有 2 个不在表单中的输入文本框，我正在尝试检索它value并将其存储在一个变量中。
This code returns undefinedin the alert box that pops up.
此代码undefined在弹出的警告框中返回。
<script>
var userPass = document.getElementById('pass');
var userName = document.getElementById('fName');
function submit(){
alert(userPass.value);
}
</script>
When I run it with userName.valueas a parameter in the alert function, it will work and display what ever you type in the box.
当我将它userName.value作为警报函数中的参数运行时，它将起作用并显示您在框中键入的任何内容。
Here is the html:
这是html：
<table id="login">
<tr>
<td><label>User Name</label></td>
</tr>
<tr>
<td colspan="2"><input class="textBox" id="fName" type="text" maxlength="30" required/></td>
</tr>
<tr>
<td id="pass"><label>Password</label></td>
<tr>
<td colspan="2"><input class="textBox" id="pass" type="text" maxlength="30" required/></td>
</tr>
<tr>
<td><input type="button" class="loginButtons" value="Login" onclick="submit();"/>   
<input type="button" class="loginButtons" value="Cancel"/></td>
</table>
采纳答案by Itay Moav -Malimovka
You will notice you have no value attr in the inputtags.
Also, although not shown, make sure the Javascript is run afterthe html is in place.
您会注意到input标签中没有值 attr 。
此外，虽然未显示，但请确保在 html 到位后运行 Javascript 。
回答by Emil Carr
<script>
function submit(){
var userPass = document.getElementById('pass');
var userName = document.getElementById('user');
alert(user.value);
alert(pass.value);
}
</script>
<input type="text" id="user" />
<input type="text" id="pass" />
<button onclick="submit();" href="javascript:;">Submit</button>
回答by Rex CoolCode Charles
// NOTE: Using "this.pass" and "this.name" will create a global variable even though it is inside the function, so be weary of your naming convention
// 注意：使用 "this.pass" 和 "this.name" 将创建一个全局变量，即使它在函数内部，所以要厌倦你的命名约定
function submit()
{
var userPass = document.getElementById("pass").value;
var userName = document.getElementById("user").value;
this.pass = userPass;
this.name = userName;
alert("whatever you want to display");
}
回答by hvgotcodes
you have multiple elements with the same id. That is a big no-no. Make sure your inputs have uniqueids.
您有多个具有相同 ID 的元素。这是一个很大的禁忌。确保您的输入具有唯一的ID。
<td id="pass"><label>Password</label></td>
<tr>
<td colspan="2"><input class="textBox" id="pass" type="text" maxlength="30" required/></td>
</tr>
see, both the tdand the inputshare the id value pass.
看， thetd和 theinput共享 id value pass。
回答by aziz punjani
Remove the id="pass"off the tdelement. Right now the js will get the td element instead of the input hence the value is undefined.
删除id="pass"关闭td元素。现在 js 将获得 td 元素而不是输入，因此该值未定义。
回答by Sham
Javascript document.getElementById("<%=contrilid.ClientID%>").value; or using jquery
Javascript document.getElementById("<%=contrilid.ClientID%>").value; 或使用 jquery
$("#<%= txt_iplength.ClientID %>").val();
$("#<%= txt_iplength.ClientID %>").val();
回答by nid
This is the sample code for the email and javascript.
这是电子邮件和 javascript 的示例代码。
params = getParams();
subject = "ULM Query of: ";
subject += unescape(params["FormsEditField3"]);
content = "Email: ";
content += unescape(params["FormsMultiLine2"]);
content += " Query: ";
content += unescape(params["FormsMultiLine4"]);
var email = "[email protected]";
document.write('<a href="mailto:'+email+'?subject='+subject+'&body='+content+'">SUBMIT QUERY</a>');
