将值传递给for循环的链接函数

Question

如果我有这样的链接函数，并希望在for循环中运行它们......如何在调用链式回调函数时确保维护上下文？

您可以在下面看到，console.log(children[i])在for循环启动时输出一个值，但在回调中未定义：

api.drawConnection = function (fromNode, toNode, bool) {
     if (bool) {
        var children = fromNode.getChildren();
        var node = null;
        var valX, valY = 0;
        node = fromNode;
        valX = 50;
        valY = 35;                                  
    //resize all node distances as children gets bigger...
     if (children.length > 0) {
        for (var i = 0; i < children.length; i++) {
            valX+=50;
            var connectPath = canvas.path("M " + node.x + " " + node.y + " z"); 
            log(children[i]); //outputs value
            children[i].set.animate({
                cx:  node.shape.attrs.cx-valX/children.length,
                cy:  node.shape.attrs.cy+valY, 
                x : node.shape.attrs.cx-valX/children.length,
                y: node.shape.attrs.cy+valY
            }, 1000, "backOut", function () {
                log(children[i]); //outputs undefined
                connectPath.animate({
                    path: ("M " + fromNode.shape.attrs.cx + " " + (fromNode.shape.attrs.cy+10) + " L " + children[i].shape.attrs.cx + " " + children[i].shape.attrs.cy + " z")
                }, 1000);
            });
        }   
      ...

我正在使用RaphaelJS，顺便说一句。