Starting with Firefox 1.5, Thunderbird 1.5, and XULRunner 1.8, you can specify an icon for a XUL window by putting files named <tt>mywindow.ico</tt> (for Windows) and <tt>mywindow.xpm</tt> (Linux), where mywindow is the id of the <window> you want to attach the icon to, in the <tt>chrome/icons/default</tt> subfolder of your bundle.
These icons will override the global icon files, which are located in <tt> app_dir /chrome/icons/default</tt>.
Older versions
为了支持早期版本, 比如 Firefox 1.0, 你必须在第一次运行时手工拷贝图标到<tt> app_dir /chrome/icons/default</tt> (example code).