Extjs Treepanel：用于更改默认图标的CSS(节点和叶子)

我有一个像 http://jsfiddle.net/bmbMy/这样的树状面板
我尝试使用css更改默认图标(节点和叶子).但那不起作用.

.x-grid-row  .x-grid-tree-node-expanded {
    background: url('http://icons.iconarchive.com/icons/sekkyumu/developpers/16/Play-Green-Button-icon.png') no-repeat center center !important;
}
.x-grid-row  .x-grid-tree-node-leaf {
    background-image:url('http://icons.iconarchive.com/icons/graphicrating/koloria/16/Button-Play-Pause-icon.png');
}

我该怎么做呢谢谢

解决方法

您没有覆盖正确的css类.这是你需要的：

.x-grid-tree-node-expanded .x-tree-icon-parent {
    background: url('http://icons.iconarchive.com/icons/sekkyumu/developpers/16/Play-Green-Button-icon.png') no-repeat center center !important;
}
.x-grid-row  .x-tree-icon-leaf {
    background-image:url('http://icons.iconarchive.com/icons/graphicrating/koloria/16/Button-Play-Pause-icon.png');
}

并更新了jsfiddle.