11

バニラのドラッグ アンド ドロップを作成する、一見単純な JavaScript の演習に苦労しています。「addeventlisteners」で間違いを犯していると思います。コードは次のとおりです。

var ele = document.getElementsByClassName ("target")[0];
var stateMouseDown = false;
//ele.onmousedown = eleMouseDown;
ele.addEventListener ("onmousedown" , eleMouseDown , false);

function eleMouseDown () {
    stateMouseDown = true;
    document.addEventListener ("onmousemove" , eleMouseMove , false);
}

function eleMouseMove (ev) {
    do {
        var pX = ev.pageX;
        var pY = ev.pageY;
        ele.style.left = pX + "px";
        ele.style.top = pY + "px";
        document.addEventListener ("onmouseup" , eleMouseUp , false);
    } while (stateMouseDown === true);
}

function eleMouseUp () {
    stateMouseDown = false;
    document.removeEventListener ("onmousemove" , eleMouseMove , false);
    document.removeEventListener ("onmouseup" , eleMouseUp , false);
}
4

4 に答える 4

12

このフィドルも試すことができますhttp://jsfiddle.net/dennisbot/4AH5Z/

<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>titulo de mi pagina</title>
<style>
    #target {
        width: 100px;
        height: 100px;
        background-color: #ffc;
        border: 2px solid blue;
        position: absolute;
    }
</style>
<script>
   window.onload = function() {
        var el = document.getElementById('target');
        var mover = false, x, y, posx, posy, first = true;
        el.onmousedown = function() {
            mover = true;
        };
        el.onmouseup = function() {
            mover = false;
            first = true;
        };
        el.onmousemove = function(e) {
            if (mover) {
                if (first) {
                    x = e.offsetX;
                    y = e.offsetY;
                    first = false;
                }
                posx = e.pageX - x;
                posy = e.pageY - y;
                this.style.left = posx + 'px';
                this.style.top = posy + 'px';
            }
        };
   }
</script>
</head>
<body>
    <div id="target" style="left: 10px; top:20px"></div>
</body>
</html>
于 2014-02-11T06:30:29.983 に答える