窗口部件预防式验证

PyQt窗口部件验证主要有两种：

1.提交后验证，会在用户提交设置数据的时候进行验证

2.预防式验证，会在用户编辑窗口部件就进行验证

本文讲述第二种验证方式，代码如下：

#encoding=utf-8
import sys
from PyQt4.QtGui import *
from PyQt4.QtCore import *

class Set_Number(QDialog):
    def __init__(self,parent=None):
        super(Set_Number,self).__init__(parent)
        #创建正则表达式
        punctuationRe = QRegExp(r"[ ,:;.]")
        thous_label = QLabel('&Thousands separatror')
        self.thous_line_edit = QLineEdit()
        #设置最大输入长度
        self.thous_line_edit.setMaxLength(1)
        #使用正则表达式验证器
        self.thous_line_edit.setValidator(QRegExpValidator(punctuationRe,self))
        thous_label.setBuddy(self.thous_line_edit)
        decimal_label = QLabel('Decimal &marker')
        self.decimal_line_edit = QLineEdit()
        self.decimal_line_edit.setMaxLength(1)
        self.decimal_line_edit.setValidator(QRegExpValidator(punctuationRe,self))
        self.decimal_line_edit.setInputMask("X")
        decimal_label.setBuddy(self.decimal_line_edit)
        places_label = QLabel('&Decimal places')
        self.places_spinbox = QSpinBox()
        self.places_spinbox.setRange(0,6)
        places_label.setBuddy(self.places_spinbox)
        buttonBox = QDialogButtonBox(QDialogButtonBox.Apply | QDialogButtonBox.Cancel)

        layout = QGridLayout()
        layout.addWidget(thous_label,0,0)
        layout.addWidget(self.thous_line_edit,0,1)
        layout.addWidget(decimal_label,1,0)
        layout.addWidget(self.decimal_line_edit,1,1)
        layout.addWidget(places_label,2,0)
        layout.addWidget(self.places_spinbox,2,1)
        layout.addWidget(buttonBox,3,1)
        self.setLayout(layout)
        self.setWindowTitle('set number format')

if __name__ == '__main__':
    app = QApplication(sys.argv)
    sn = Set_Number()
    sn.show()
    sys.exit(app.exec_())