另类的拖拽

页面添加监听事件

if(dojo.isIE){
		dojo.connect(dijit.byId("selectedSelection"), "onMouseUp", doPSFieldSelect);
	}else{
		dojo.query("BODY").connect("onmouseup",dragAndDropBetweenSelector);
	}

判断鼠标是否移动到目标元素上

function dragAndDropBetweenSelector(ev){
    var target = ev.srcElement || ev.originalTarget;
    if ((!dojo.isIE && target.id !== "availableSelection" )||
        ( dojo.isIE && target.id !=="selectedSelection")){
        return;
    }
    var mousePos=getMousePosition(ev);
    var targPos=getSelectorPos("selectedSelection");
    var curTarget=dojo.byId("selectedSelection");
    var targWidth = parseInt(curTarget.offsetWidth,10); 
    var targHeight = parseInt(curTarget.offsetHeight,10); 
    if ((mousePos.x > targPos.x) && 
        (mousePos.x < (targPos.x + targWidth)) && 
        (mousePos.y > targPos.y) && 
        (mousePos.y < (targPos.y + targHeight))
        ) 
    { 
        // dragObject was dropped onto curTarget! 
        doPSFieldSelect();
    } 
}

判断元素位置

function getSelectorPos(elementId) {
    var ua = navigator.userAgent.toLowerCase();
    var isOpera = (ua.indexOf('opera') != -1);
    var isIE = (ua.indexOf('msie') != -1 && !isOpera); // not opera spoof
    var el = document.getElementById(elementId);
    if(el.parentNode === null || el.style.display == 'none') 
    {
        return false;
    }
    var parent = null;
    var pos = [];
    var box;
    if(el.getBoundingClientRect)    //IE
    {
        box = el.getBoundingClientRect();
        var scrollTop = Math.max(document.documentElement.scrollTop, document.body.scrollTop);
        var scrollLeft = Math.max(document.documentElement.scrollLeft, document.body.scrollLeft);
        return {x:box.left + scrollLeft, y:box.top + scrollTop};
    }
    else if(document.getBoxObjectFor)   // gecko
    {
        box = document.getBoxObjectFor(el);
        var borderLeft = (el.style.borderLeftWidth)?parseInt(el.style.borderLeftWidth,10):0;
        var borderTop = (el.style.borderTopWidth)?parseInt(el.style.borderTopWidth,10):0;
        pos = [box.x - borderLeft, box.y - borderTop];
    }
    else    // safari & opera
    {
        pos = [el.offsetLeft, el.offsetTop];
        parent = el.offsetParent;
        if (parent != el) {
            while (parent) {
                pos[0] += parent.offsetLeft;
                pos[1] += parent.offsetTop;
                parent = parent.offsetParent;
            }
        }
        if (ua.indexOf('opera') !== -1 || ( ua.indexOf('safari') !== -1 && el.style.position === 'absolute' )) 
        {
                pos[0] -= document.body.offsetLeft;
                pos[1] -= document.body.offsetTop;
        } 
    }
    if (el.parentNode) { parent = el.parentNode; }
    else { parent = null; }
    while (parent && parent.tagName != 'BODY' && parent.tagName != 'HTML') 
    { // account for any scrolled ancestors
        pos[0] -= parent.scrollLeft;
        pos[1] -= parent.scrollTop;
        if (parent.parentNode) { parent = parent.parentNode; } 
        else { parent = null; }
    }
    return {x:pos[0], y:pos[1]};
}

判断鼠标位置

function getMousePosition(ev){
    if(ev.pageX || ev.pageY){
        return {x:ev.pageX, y:ev.pageY};
    }
    return {
        x:ev.clientX + document.body.scrollLeft - document.body.clientLeft,
        y:ev.clientY + document.body.scrollTop  - document.body.clientTop
    };
}