JavaScript

<body>
        <input type="checkbox"  onmouseover="document.getElementById('div1').style.display = 'block'" onmouseout="document.getElementById('div1').style.display='none'"/>
        <div id = "div1">
            for your information safety...
        </div>
    </body>

onmouseover,onmouseout

onmouseover = "document.getElementById('div1').style.display = 'block' ";

<body>
    <div id="div1" onmouseover="ToGreen()" onmouseout="ToRed()">

    </div>
</body>
<script>
        function ToGreen() {
            var oDiv = document.getElementById('div1');
            oDiv.style.width = '300px';
            oDiv.style.height = '300px';
            oDiv.style.background = 'green';
        }
        function ToRed() {
            var oDiv = document.getElementById('div1');
            oDiv.style.width = '200px';
            oDiv.style.height = '200px';
            oDiv.style.background = 'red';
        }
    </script>

关联到了函数

onmouseover = "ToGreen ( ) ";

var oDiv = document.getElementById('div1');//获取节点

<body>
    <input id="btn1" type="button" value="全选" /><br>
    <input id="btn2" type="button" value="不选" /><br>
    <input id="btn3" type="button" value="反选" /><br>
    <div id="div1">
        <input type="checkbox" /><br>
        <input type="checkbox" /><br>
        <input type="checkbox" /><br>
        <input type="checkbox" /><br>
        <input type="checkbox" /><br>
        <input type="checkbox" /><br>
        <input type="checkbox" /><br>
        <input type="checkbox" /><br>
        <input type="checkbox" /><br>
        <input type="checkbox" /><br>
        <input type="checkbox" /><br>
    </div>
</body>
<script>
        var i;
        window.onload = function () {
            var Btn1 = document.getElementById('btn1');
            var Btn2 = document.getElementById('btn2');
            var Div1 = document.getElementById('div1');
            var cekb = Div1.getElementsByTagName('input');
            var Btn3 = document.getElementById('btn3');
            Btn1.onclick = function () {
                for (i = 0; i < cekb.length; i++) {
                    cekb[i].checked = true;
                }
            }
            Btn2.onclick = function () {
                for (i = 0; i < cekb.length; i++) {
                    cekb[i].checked = false;
                }
            }
            Btn3.onclick = function () {
                for (i = 0; i < cekb.length; i++) {
                    if (cekb[i].checked == true) {
                        cekb[i].checked = false;
                    }
                    else {
                        cekb[i].checked = true;
                    }
                }
            }

        }
    </script>

window.onload  = function()

{

}

Btn1.onclick = function () {
for (i = 0; i < cekb.length; i++) {
cekb[i].checked = true;
}
}
原文地址:https://www.cnblogs.com/Artimis-fightting/p/10949633.html