这 可能会
有所帮助（可能最好使用jQuery，onDomReady并毫不干扰地将keydown事件添加到textarea），但已在IE7和FF3中进行了测试：
<html> <head><title>Test</title></head> <body> <script type="text/javascript"> var keynum, lines = 1; function limitLines(obj, e) { // IE if(window.event) { keynum = e.keyCode; // Netscape/Firefox/Opera } else if(e.which) { keynum = e.which; } if(keynum == 13) { if(lines == obj.rows) { return false; }else{ lines++; } } } </script> <textarea rows="4" onkeydown="return limitLines(this, event)"></textarea> </body></html>*编辑-说明：如果按下ENTER键，它将捕获按键，并且如果textarea中的行与textarea的行数相同，则不添加新行。否则，它将增加行数。
编辑＃2： 考虑到人们仍然在回答这个问题，我想我会尽可能地对其进行更新以处理粘贴，删除和剪切。
<html><head> <title>Test</title> <style> .limit-me { height: 500px; width: 500px; } </style></head><body><textarea rows="4" ></textarea><script> var lines = 1; function getKeyNum(e) { var keynum; // IE if (window.event) { keynum = e.keyCode; // Netscape/Firefox/Opera } else if (e.which) { keynum = e.which; } return keynum; } var limitLines = function (e) { var keynum = getKeyNum(e); if (keynum === 13) { if (lines >= this.rows) { e.stopPropagation(); e.preventDefault(); } else { lines++; } } }; var setNumberOfLines = function (e) { lines = getNumberOfLines(this.value); }; var limitPaste = function (e) { var clipboardData, pastedData; // Stop data actually being pasted into div e.stopPropagation(); e.preventDefault(); // Get pasted data via clipboard API clipboardData = e.clipboardData || window.clipboardData; pastedData = clipboardData.getData('Text'); var pastedLines = getNumberOfLines(pastedData); // Do whatever with pasteddata if (pastedLines <= this.rows) { lines = pastedLines; this.value = pastedData; } else if (pastedLines > this.rows) { // alert("Too many lines pasted "); this.value = pastedData .split(/rn|r|n/) .slice(0, this.rows) .join("n "); } }; function getNumberOfLines(str) { if (str) { return str.split(/rn|r|n/).length; } return 1; } var limitedElements = document.getElementsByClassName('limit-me'); Array.from(limitedElements).forEach(function (element) { element.addEventListener('keydown', limitLines); element.addEventListener('keyup', setNumberOfLines); element.addEventListener('cut', setNumberOfLines); element.addEventListener('paste', limitPaste); });</script></body></html>欢迎分享，转载请注明来源：内存溢出
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