def msg(self,Filepath):
    directory = QtWidgets.QFileDialog.getExistingDirectory(None,"选取文件夹","C:/") # 起始路径
    self.fileT.setText(directory)

  def msg(self,Filepath):
    directory = QtWidgets.QFileDialog.getOpenFileName(self, "选取文件","./", "All Files (*);;Text Files (*.txt)") 
 #当窗口非继承QtWidgets.QDialog时，self需替换成 None

  def msg(self,Filepath):
    directory = QtWidgets.QFileDialog.getOpenFileNames(self, self, "选取多个文件", "./","All Files (*);;Text Files (*.txt)") 
 #当窗口非继承QtWidgets.QDialog时，self需替换成 None

  def msg(self,Filepath):
    directory = QtWidgets.QFileDialog.getSaveFileName(self, "设置路径","./","All Files (*);;Text Files (*.txt)") 
 #当窗口非继承QtWidgets.QDialog时，self需替换成 None

from PyQt5 import QtCore, QtWidgets
import sys
##########################################
#ui界面设置
class Ui_MainWindow(object):
  def setupUi(self, MainWindow):
  
    #主窗口参数设置
    MainWindow.setObjectName("MainWindow")
    MainWindow.resize(848, 721)
    self.centralwidget = QtWidgets.QWidget(MainWindow)
    self.centralwidget.setObjectName("centralwidget")
    # 设置按键参数
    self.file = QtWidgets.QPushButton(self.centralwidget)
    self.file.setGeometry(QtCore.QRect(57, 660, 175, 28))
    self.file.setObjectName("file")
    self.file.setStyleSheet(" margin: 0px; padding: 0px;">)
    self.file.setStyleSheet(
      "QPushButton{ margin: 0px; padding: 0px;">"QPushButton:hover{color:green}" # 光标移动到上面后的前景色
      "QPushButton{border-radius:6px}" # 圆角半径
      "QPushButton:pressed{border: None;}" # 按下时的样式
    )
    # 设置显示窗口参数
    self.fileT = QtWidgets.QPushButton(self.centralwidget)
    self.fileT.setGeometry(QtCore.QRect(300, 660, 480, 28))
    self.fileT.setObjectName("file")
    self.fileT.setStyleSheet(" margin: 0px; padding: 0px;">)
    self.fileT.setStyleSheet(
      "QPushButton{ margin: 0px; padding: 0px;">"QPushButton:hover{color:green}" # 光标移动到上面后的前景色
      "QPushButton{border-radius:6px}" # 圆角半径
      "QPushButton:pressed{border: None;}" # 按下时的样式
    )
    #主窗口及菜单栏标题栏设置
    MainWindow.setCentralWidget(self.centralwidget)
    self.menubar = QtWidgets.QMenuBar(MainWindow)
    self.menubar.setGeometry(QtCore.QRect(0, 0, 848, 26))
    self.menubar.setObjectName("menubar")
    MainWindow.setMenuBar(self.menubar)
    self.statusbar = QtWidgets.QStatusBar(MainWindow)
    self.statusbar.setObjectName("statusbar")
    MainWindow.setStatusBar(self.statusbar)
    self.retranslateUi(MainWindow)
    QtCore.QMetaObject.connectSlotsByName(MainWindow)
    ################button按钮点击事件回调函数################
    self.file.clicked.connect(self.msg)
  def retranslateUi(self, MainWindow):
    _translate = QtCore.QCoreApplication.translate
    MainWindow.setWindowTitle(_translate("MainWindow", "Deecamp_Eurus"))
    self.file.setText(_translate("MainWindow", "选择文件"))
    self.fileT.setText(_translate("MainWindow", ""))
  #########选择图片文件夹#########
  def msg(self,Filepath):
    m = QtWidgets.QFileDialog.getExistingDirectory(None,"选取文件夹","C:/") # 起始路径
    self.fileT.setText(m)
#########主函数入口 #########
if __name__ == '__main__':
  app = QtWidgets.QApplication(sys.argv)
  mainWindow = QtWidgets.QMainWindow()
  ui = Ui_MainWindow()
  ui.setupUi(mainWindow)
  mainWindow.show()
  sys.exit(app.exec_())

self.pushButton.clicked.connect(self.btn1_click)#设置绑定事件
def btn1_click(self):
filename,_=QFileDialog.getOpenFileName(QWidget(),'open',r"E:\images1")
#打开文件或者如下：getOpenFileName第一个参数要求是QWidget对象
#filename,_=QFileDialog.getOpenFileName(None,'open',r"E:\images1",' ')
  img=QImage()
  img.load(filename)
#更改图片大小,适应graphicsView窗口大小
  img=img.scaled(self.graphicsView.width(),self.graphicsView.height())
#一个问题是:img=img.scaled(width=self.graphicsView.width(),height=self.graphicsView.height())这样
#会出错，不知道什么原因
scene = QGraphicsScene () scene. addPixmap ( QPixmap (). fromImage (img)) self .graphicsView. setScene (scene)