输入验证以及如何改进它

Posted 2021-05-04

我已经组合了一个输入验证函数（目前没有使用try / except块）。

它工作但纠错带来奇怪的行为......即一旦用户纠正了错误，他们必须按两次计算按钮才能正确触发？

def validation(self):

    partval = self.partDiaText.text()
    partlentext = self.partLenText.text()
    matdia = self.matDiaText.text()

    if partval.isalpha():
        self.error_label.setText("The part diameter must be a number!")
        self.partDiaText.setText("")

    elif partval == 0:
        self.error_label.setText("The part diameter must be greater than zero!")

    elif partlentext.isalpha():
        self.partLenText.setText("")
        self.error_label.setText("The part length must be a number!")

    elif partlentext == 0:
        self.error_label.setText("The part length must be greater than zero!")

    elif matdia.isalpha():
        self.matDiaText.setText("")
        self.error_label.setText("The material diameter must be a number!")

    elif matdia == 0:
        self.error_label.setText("The material diameter must be greater than zero!")


    else:
        self.error_label.clear()
        self.pushButton_2.clicked.connect(self.reset_output)
        self.pushButton_2.clicked.connect(self.calc_machining)
        self.pushButton_2.clicked.connect(self.calc_times)
        self.pushButton_2.clicked.connect(self.calc_qtyVar)
        self.pushButton_2.clicked.connect(self.work_centre)
        self.pushButton_2.clicked.connect(self.material_code)

编辑：即使没有错误，我仍然需要按两次pushbutton_2才能触发clicked.connects。如果我将所有clicked.connects从验证函数中取出并将它们放入主init函数中，它会正确触发，但输入上没有任何变量。

答案

我的猜测是，正如@noidsirius暗示的那样，第一次使用clic时，会执行验证并连接clic-to-slots。第二次确实执行了插槽。

如果这个猜测是正确的，解决方案可能是：

def __init__(self):
    self.pushButton_2.clicked.connect(self.validate_and_run_if_ok)
    # etc.

def validate_and_run_if_ok(self):

    partval = self.partDiaText.text()
    partlentext = self.partLenText.text()
    matdia = self.matDiaText.text()

    if partval.isalpha():
        self.error_label.setText("The part diameter must be a number!")
        self.partDiaText.setText("")

    elif partval == 0:
        self.error_label.setText("The part diameter must be greater than zero!")

    elif partlentext.isalpha():
        self.partLenText.setText("")
        self.error_label.setText("The part length must be a number!")

    elif partlentext == 0:
        self.error_label.setText("The part length must be greater than zero!")

    elif matdia.isalpha():
        self.matDiaText.setText("")
        self.error_label.setText("The material diameter must be a number!")

    elif matdia == 0:
        self.error_label.setText("The material diameter must be greater than zero!")


    else:
        self.error_label.clear()
        self.reset_output()
        self.calc_machining()
        self.calc_times()
        self.calc_qtyVar()
        self.work_centre()
        self.material_code()

（唯一的修改是else块，以及init的附加行）