PyQt基本布局常用方法之addStretch

from PyQt4.QtGui import *from PyQt4.QtCore import *import sys class LayoutDialog(QDialog):    def __init__(self,parent=None):        super(LayoutDialog,self).__init__(parent)        self.resize(200,600)        btn1    =   QPushButton("btn1")        btn2    =   QPushButton("btn2")        btn3    =   QPushButton("btn3")        vlayout =   QVBoxLayout(self)        vlayout.addStretch(1)        vlayout.addWidget(btn1)        vlayout.addStretch(1)        vlayout.addWidget(btn2)        vlayout.addStretch(2)        vlayout.addWidget(btn3)app = QApplication(sys.argv)dialog = LayoutDialog()dialog.show()app.exec_()

我们先看一下addStretch的原型：

QBoxLayout.addStretch (self, int stretch =0)

Adds a stretchable space (a QSpacerItem)with zero minimum size and stretch factor stretch to the end of this boxlayout.

See also insertStretch(), addItem(), andQSpacerItem.

然后通过上面的代码来学习一下addStretch的用法。

达到的效果图如下：

所以该函数的作用就是平分布局，它所带的参数就是所占的比例。