svg動(dòng)態(tài)添加的line的起始坐標(biāo)，終止坐標(biāo)都對(duì)了，但是顯示在界面上的跟實(shí)際上不同

用jquery動(dòng)態(tài)獲取A001節(jié)點(diǎn)的坐標(biāo)，C001節(jié)點(diǎn)的坐標(biāo)，坐標(biāo)值看起來(lái)是對(duì)的，但是實(shí)際上svg的line線后，顯示在頁(yè)面上的位置不對(duì)？實(shí)際上我要的是A001連接C001的點(diǎn)，但線感覺(jué)上平移了。

獲取到的起點(diǎn)終點(diǎn)坐標(biāo)為：

startX:440
startY:175
endX:301.421875
endY:255
startLeft:440
startTop:225
endLeft:401.421875
endTop:305

動(dòng)態(tài)添加的line為:

<line id="line0" xmlns="http://www.w3.org/2000/svg" stroke="#000" stroke-width="2" marker-end="url(#arrow)" stroke-dasharray="10,10" x1="440" y1="225" x2="401.421875" y2="305"></line>

以下為獲取畫line的方法：

function addLine(index, startId, endId) {
    //獲取起始節(jié)點(diǎn)和終止節(jié)點(diǎn)的連線坐標(biāo)
    var startX = $(startId).offset().left;
    var startY = $(startId).offset().top;
    var startLeft = 0;
    var startTop = 0;
    var endX = $(endId).offset().left;
    var endY = $(endId).offset().top;
    var endLeft = 0;
    var endTop = 0;
    //下述考慮起始點(diǎn)和終止點(diǎn)不在同一水平線上的坐標(biāo)
    if (startY != endY) {
        //如果起始點(diǎn)在終止點(diǎn)左邊，則起始點(diǎn)需要left+width，top+ 1/2 height;終止點(diǎn)left,top+ 1/2 height
        if (startX < endX) {
            startLeft = startX + $(startId).width();
            startTop = startY + $(startId).height() / 2;
            endLeft = endX;
            endTop = endY + $(endId).height() / 2;
        }
        //如果起始點(diǎn)在終止點(diǎn)右邊，則起始點(diǎn)需要left,top+1/2 height;終止點(diǎn)left+width,top + 1/2 height
        if (startX > endX) {
            startLeft = startX;
            startTop = startY + $(startId).height() / 2;
            endLeft = endX+$(endId).width();
            endTop = endY + $(endId).height() / 2;
        }
        //如果起始點(diǎn)跟終止點(diǎn)在同一條垂直線上，則起始點(diǎn)left+1/2width,top+height;終止點(diǎn)left+1/2width,top
        if (startX == endX) {
            startLeft = startX + $(startId).width() / 2;
            startTop = startY + $(startId).height();
            endLeft = endX + $(endId).width() / 2;
            endTop = endY;
        }
    }
    //下述考慮起始點(diǎn)和終止點(diǎn)在同一水平線上的坐標(biāo)
    else{
        //如果起始點(diǎn)在終止點(diǎn)左邊，則起始點(diǎn)需要left+width;終止點(diǎn)left
        if (startX < endX) {
            startLeft = startX + $(startId).width();
            startTop = startY + $(startId).height() / 2;
            endLeft = endX;
            endTop = endY + $(endId).height() / 2;
        }
        //如果起始點(diǎn)在終止點(diǎn)右邊，則起始點(diǎn)需要left;終止點(diǎn)left+width
        if (startX > endX) {
            startLeft = startX;
            startTop = startY + $(startId).height() / 2;
            endLeft = endX+$(endId).width();
            endTop = endY + $(endId).height() / 2;
        }
        //起始點(diǎn)和終止點(diǎn)重合了，不需要畫線
        if (startX == endX) {
        }
    }

    var line = "<line" + " id=line" + index + " xmlns='http://www.w3.org/2000/svg' stroke='#000' stroke-width='2' marker-end='url(#arrow)' stroke-dasharray='10,10'></line>";
    console.log("startX:" + startX);
    console.log("startY:" +startY);
    console.log("endX:" + endX);
    console.log("endY:" + endY);
    console.log("startLeft:" + startLeft);
    console.log("startTop:" + startTop);
    console.log("endLeft:" + endLeft);
    console.log("endTop:" + endTop);
    var svg = d3.select('#wrap')
    $(line).appendTo($("#wrap"));

    $('#line' + index).attr({ x1: startLeft, y1: startTop, x2: endLeft, y2: endTop });
    svg.html(svg.html());//需要重寫父元素，否則html添加了，但是頁(yè)面不顯示
    console.log(svg.html());

}
$("#test").on("click", function () {
    addLine(0, "#A001", "#C002");
})

知道應(yīng)該怎么解決嗎？