使用Qt example mainwindow/Application时,修改文件,如果按x关闭窗口,弹出对话框询问是否保留修改,如果不做选择,过几秒后,系统会弹出对话框“Window with title"untitled.txt* -application is not responding.This window belongs to application application(PID = xxxx,hostname =localhost).Do you wish to terminate this application?(All unsaved data will be lost in this application.) Terminate , continue”,如何让系统不弹出此对话框?