救助：PyQt4 中如何设置窗口关联？
Level1 -> Level2 -> Level3
只要顶层的窗口关闭，它的子窗口也全部关闭

或者，如何能让子窗口在最顶层？ 像Warning一样，不关掉无法操作其它窗口
[解决办法]
#coding: utf-8

from PyQt4.Qt import *
from PyQt4.QtCore import *
from PyQt4.QtGui import *


def main():
print "main"


if __name__ == "__main__":
import sys
app = QApplication(sys.argv)
print type(Qt.WindowModal)
widget1 = QWidget()
widget1.resize(600,400)
widget1.setStyleSheet(QString.fromUtf8("background:black"))


widget2 = QWidget(widget1,Qt.Window)
widget2.setWindowModality(Qt.ApplicationModal)
widget2.resize(400,200)
widget2.setStyleSheet(QString.fromUtf8("background:red"))

widget3 = QWidget(widget2,Qt.Window)
widget3.setWindowModality(Qt.ApplicationModal)
widget3.setStyleSheet(QString.fromUtf8("background:white"))
widget3.resize(300,100)

widget1.show()
widget2.show()
widget3.show()
app.exec_()



满意记得结贴啊