textarea with limited lines and char limits

问题

i need functionaliy which will have TextArea with

1) maximum total lines- 6 and 
2) in each line there must be maximum of 16 chars
3) if user enters 17th character the cursor should go to the next line 
and user will type in there (the line will be counted)
4) if user reaches to the 7th line it will not allow user to write
5) if user type e.g "Hello, I Love StackOverflow and its features" (counting 
from 1st Char 'H', the 16th char is 't' but it is whole word 'StackOverflow',
    it shouldn't break and continue to next line e.g.
        Hello, I Love St
        ackOverflow
now the whole word should come to next line like:

        Hello, I Love
        StackOverflow 
        and its features

here is the link what i have done so far http://jsfiddle.net/nqjQ2/2/

sometimes some of the functionality work, some times not, and facing browser issues for onKeyUp and onKeyDown can anyone help me with it ?

回答1:

I think this is mostly what you want:

<textarea id="splitLines"></textarea>

JavaScript:

var textarea = document.getElementById("splitLines");
textarea.onkeyup = function() {
    var lines = textarea.value.split("\n");
    for (var i = 0; i < lines.length; i++) {
        if (lines[i].length <= 16) continue;
        var j = 0; space = 16;
        while (j++ <= 16) {
            if (lines[i].charAt(j) === " ") space = j;
        }
        lines[i + 1] = lines[i].substring(space + 1) + (lines[i + 1] || "");
        lines[i] = lines[i].substring(0, space);
    }
    textarea.value = lines.slice(0, 6).join("\n");
};

See the fiddle in action.

回答2:

In Jquery

$(function () {

    var limit = function (event) {
        var linha = $(this).attr("limit").split(",")[0];
        var coluna = $(this).attr("limit").split(",")[1];

        var array = $(this)
            .val()
            .split("\n");

        $.each(array, function (i, value) {
            array[i] = value.slice(0, linha);
        });

        if (array.length >= coluna) {
            array = array.slice(0, coluna);
        }

        $(this).val(array.join("\n"))

    }

    $("textarea[limit]")
        .keydown(limit)
        .keyup(limit);

})



<textarea limit='10,5'  cols=10 rows=5 ></textarea>

http://jsfiddle.net/PVv6c/

来源：https://stackoverflow.com/questions/14259580/textarea-with-limited-lines-and-char-limits

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javascript

jquery

html

textarea