Enter key in textarea | 易学教程

问题

I have a textarea, On every Enter key pressed in textarea I want new line to be started with a bullet say (*). How to go about it ?

No jQuery please.

I can observe for the Enter key , after that !? Should I have to get the whole value of textarea and append * to it and again fill the textarea ?

回答1:

You could do something like this:

<body>

<textarea id="txtArea" onkeypress="onTestChange();"></textarea>

<script>
function onTestChange() {
    var key = window.event.keyCode;

    // If the user has pressed enter
    if (key === 13) {
        document.getElementById("txtArea").value = document.getElementById("txtArea").value + "\n*";
        return false;
    }
    else {
        return true;
    }
}
</script>

</body>

Although the new line character feed from pressing enter will still be there, but its a start to getting what you want.

回答2:

Simply add this tad to your textarea.

onkeydown="if(event.keyCode == 13) return false;"

回答3:

You need to consider the case where the user presses enter in the middle of the text, not just at the end. I'd suggest detecting the enter key in the keyup event, as suggested, and use a regular expression to ensure the value is as you require:

<textarea id="t" rows="4" cols="80"></textarea>
<script type="text/javascript">
    function formatTextArea(textArea) {
        textArea.value = textArea.value.replace(/(^|\r\n|\n)([^*]|$)/g, "$1*$2");
    }

    window.onload = function() {
        var textArea = document.getElementById("t");
        textArea.onkeyup = function(evt) {
            evt = evt || window.event;

            if (evt.keyCode == 13) {
                formatTextArea(this);
            }
        };
    };
</script>

回答4:

My scenario is when the user strikes the enter key while typing in textarea i have to include a line break.I achieved this using the below code......Hope it may helps somebody......

function CheckLength()
{
    var keyCode = event.keyCode
    if (keyCode == 13)
    {
        document.getElementById('ctl00_ContentPlaceHolder1_id_txt_Suggestions').value = document.getElementById('ctl00_ContentPlaceHolder1_id_txt_Suggestions').value + "\n<br>";
    }
}

回答5:

You could do something like this:

$("#txtArea").on("keypress",function(e) {
    var key = e.keyCode;

    // If the user has pressed enter
    if (key == 13) {
        document.getElementById("txtArea").value =document.getElementById("txtArea").value + "\n";
        return false;
    }
    else {
        return true;
    }
});

<textarea id="txtArea"></textarea>

来源：https://stackoverflow.com/questions/2099661/enter-key-in-textarea

标签

javascript

textarea