如何在Python 3.5 + PyQt5中更新/设置标签

Question

我有一个用Qt设计师创建的表单。表单必须通过filedialog打开文件。这很好用。

但是我无法使用所选的文件路径更新标签。当我将filedialog的代码直接放在标签代码中时，标签设置正确。

部分代码如下：

import sys
from PyQt5 import QtCore, QtWidgets, QtGui
from PyQt5.QtWidgets import QWidget, QFileDialog

class Ui_Form(QWidget):
    def setupUi(self, Form):
        Form.setObjectName("Form")
        Form.resize(499, 297)
        self.toolButton = QtWidgets.QToolButton(Form)
        self.toolButton.setGeometry(QtCore.QRect(20, 150, 25, 19))
        self.toolButton.setObjectName("toolButton")
        self.label = QtWidgets.QLabel(Form)
        self.label.setGeometry(QtCore.QRect(20, 180, 311, 16))
        self.label.setObjectName("label")

        self.retranslateUi(Form)
        QtCore.QMetaObject.connectSlotsByName(Form)

    def retranslateUi(self, Form):
        _translate = QtCore.QCoreApplication.translate
        Form.setWindowTitle(_translate("Form", "Form"))

        self.toolButton.setText(_translate("Form", "..."))
        self.toolButton.clicked.connect(self.InputFile)

        self.label.setText(_translate("Form", "TextLabel"))

    def InputFile(self):
        print("Input file printing")
        fileName, _ = QFileDialog.getOpenFileName(self,"Select File", "","All Files (*);;Python Files (*.py)")
        if fileName:
            InputLabel = fileName
            print(InputLabel)


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    Form = QtWidgets.QWidget()
    ui = Ui_Form()
    ui.setupUi(Form)
    Form.show()
    sys.exit(app.exec_())