Why is my element value not getting changed? Am I using the wrong function?

问题

I have an asp.net mvc application and i am trying to assign value to my textbox dynamically, but it seems to be not working (I am only testing on IE right now). This is what I have right now..

document.getElementsByName('Tue').Value = tue; (by the way tue is a variable)

I have also tried this variation but it didnt work either.

document.getElementsById('Tue').Value = tue; (by the way tue is a variable)

Can someone where please tell me where I am going wrong with this?

回答1:

It's document.getElementById, not document.getElementsByID

I'm assuming you have <input id="Tue" ...> somewhere in your markup.

回答2:

How to address your textbox depends on the HTML-code:

<!-- 1 --><input type="textbox" id="Tue" />
<!-- 2 --><input type="textbox" name="Tue" />

If you use the 'id' attribute:

var textbox = document.getElementById('Tue');

for 'name':

var textbox = document.getElementsByName('Tue')[0]

(Note that getElementsByName() returns all elements with the name as array, therefore we use [0] to access the first one)

Then, use the 'value' attribute:

textbox.value = 'Foobar';

回答3:

There are two issues in your code.

Use getElementByName instead of getElement**s**ByName
use the value in lowercase instead of Value.

回答4:

If you are using Chrome, then debug with the console. Press SHIFT+CTRL+j to get the console on screen.

Trust me, it helps a lot.

回答5:

Sounds like we need to assume that your textbox name and ID are both set to "Tue." If that's the case, try using a lower-case V on .value.

回答6:

As the plural in getElementsByName() implies, does it always return list of elements that have this name. So when you have an input element with that name:

<input type="text" name="Tue">

And it is the first one with that name, you have to use document.getElementsByName('Tue')[0] to get the first element of the list of elements with this name.

Beside that are properties case sensitive and the correct spelling of the value property is .value.

回答7:

You can use

formname.textboxname.value="delete";

来源：https://stackoverflow.com/questions/477543/why-is-my-element-value-not-getting-changed-am-i-using-the-wrong-function

标签

javascript

textbox