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昨天在课堂上，我的老师放了一些代码让我们在家测试，但我似乎无法让代码工作。代码应该做的是在按住鼠标的同时移动一个 div。我给我的朋友看了，我们认为问题出在：

calculator.style.top = getStyle(calculator, "top");
calculator.style.left = getStyle(calculator, "left");

function getStyle(object,styleName)
{
 if (window.getComputedStyle)
  {
    return document.defaultView.getComputedStyle(object, null).getPropertyValue(styleName);
  }
 else if (object.currentStyle)
   {
    return object.currentStyle[styleName];
   }
}

但我们似乎仍然无法让它发挥作用。帮助将不胜感激。这里还有完整的代码，以防您需要查看它：

diffx = null;
diffy = null;
off = document.getElementById("buttonOff");
on = document.getElementById("calcButton");
calculator = document.getElementById("calculator");
calculator.style.top = getStyle(calculator, "top");
calculator.style.left = getStyle(calculator, "left");

function getStyle(object,styleName)
{
 if (window.getComputedStyle)
  {
    return document.defaultView.getComputedStyle(object, null).getPropertyValue(styleName);
  }
 else if (object.currentStyle)
   {
    return object.currentStyle[styleName];
   }
}

function grabCalculator(e)
{
            var evt = e || window.event;
            calculator = evt.target || evt.srcElement;
            var mousex = evt.clientX;
            var mousey = evt.clientY;
            diffx = parseInt(calculator.style.left) – mousex;
            diffy = parseInt(calculator.style.top) – mousey;
            addEvent(document, "mousemove", moveCalculator, false);
            addEvent(document, "mouseup", dropCalculator, false);
}

function moveCalculator(e)
{
            var evt = e || window.event;
            var mousex = evt.clientX;
            var mousey = evt.clientY;
            calculator.style.left = mousex + diffx + "px";
            calculator.style.top = mousey + diffy + "px";
}

function addEvent(obj, eventType, fnName, cap)
{
            if (obj.attachEvent)
            {
                        obj.attachEvent("on" + eventType, fnName);
            }

            else
            {
                        obj.addEventListener(eventType, fnName, cap);
            }
}

function removeEvent(obj, eventType, fnName, cap)
{
            if (obj.attachEvent)
            {
                        obj.detachEvent("off" + eventType, fnName);
            }

            else
            {
                obj.removeEventListener(eventType, fnName, cap);
            }
}

function dropCalculator(e)
{
            removeEvent(document,"mousemove", moveCalculator, false);
            removeEvent(document, "mouseup", dropCalculator, false);
}

function main() {
    alert("TEST");
    //store top and left values of calculator
    calculator.style.top = getStyle(calculator, "top");
    calculator.style.left = getStyle(calculator, "left");
    calcButtonState = true;

}

window.onload = main;

再次感谢！桑德罗

编辑：添加 Jsfiddle 链接：http: //jsfiddle.net/7225J/

（而且输出看起来很糟糕，因为它不应该被调整到那么小）

4

2 回答 2

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我认为您的问题出在 GrabCalculator 函数中。尝试改变：

diffx = parseInt(calculator.style.left) – mousex;
diffy = parseInt(calculator.style.top) – mousey;

至：

diffx = parseInt(calculator.offsetLeft) – mousex;
diffy = parseInt(calculator.offsetTop) – mousey;

也把它放在主要的：

addEvent(..., grabCalculator, ...);
于 2013-02-24T05:56:12.987 回答
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在 main 中，设置初始计算器坐标，如下所示：

calculator.style.top = 0 + "px";
calculator.style.left = 0 + "px";

根本不要使用 getStyle 。之后直接访问即可。它将起作用，因为您将这两行放入主行。

于 2013-02-24T23:36:23.070 回答