该切换函数将返回一个新的布尔值，如果它被点击。
The Toggle function will return a new Boolean value if it is clicked.
task_tick：该函数通常调用自timetick函数；它可能引起进程切换。
Task_tick: This function is mostly called from time tick functions; it might lead to process switch.
函数的作用是：切换到当前目录的父目录（上一步）。
The ftp_cdup() function changes the current directory to the parent directory (one step up).
此方法触发beforetabchange事件，若处理函数返回false则取消tab切换。
This method fires the beforetabchange event which can return false to cancel the TAB change.
此方法触发beforetabchange事件，若处理函数返回false则取消tab切换。
This method fires the beforetabchange event which can return false to cancel the TAB change.
应用推荐