使用修改鍵在pyqt4中拖放

Question

請考慮以下最簡單的示例。如何在下拉代碼中的註釋中指出在放置事件期間按下修飾鍵時如何修改它，以及是否執行其他操作。假設你從鸚鵡螺或類似的東西中刪除一個文件到我的例子中。

#!/usr/bin/python 
# -*- coding: utf-8 -*- 

import sys 
from PyQt4.QtGui import * 
from PyQt4.QtCore import * 

class MyDropLabel(QLabel): 
    myDroppedSignal = pyqtSignal(str)  
    myDroppedSignalModified = pyqtSignal()  

    def __init__(self,text): 
     super(MyDropLabel, self).__init__(text) 
     self.setAcceptDrops(True) 

    def dragMoveEvent(self, e): 
     e.accept() 

    def dragEnterEvent(self, e): 
     e.accept() 

    def dropEvent(self, e): 
     if e.mimeData().hasUrls(): 
      s = e.mimeData().urls()[0].path() 
      self.myDroppedSignal.emit(s) 
     e.accept() 

##if a modifier key, for example shift or ctrl was pressed to something else and emit myDroppedSignalModified 




class MyWidget(QWidget): 


    def __init__(self, parent=None): 
     QWidget.__init__(self, parent) 
     self.hlayout = QHBoxLayout() 
     self.setLayout(self.hlayout) 
     self.label = MyDropLabel("Drop something here") 
     self.hlayout.addWidget(self.label) 
     #self.setCentralWidget(self.label) 

     self.label.myDroppedSignal.connect(self.myDroppedHandler) 

    def myDroppedHandler(self,s): 
     self.label.setText(QString(s)) 

if __name__ == "__main__": 
    app = QApplication(sys.argv) 
    da = MyWidget() 
    da.show() 
    sys.exit(app.exec_()) 

Answer 1

可以，例如，通過installEventFilter(QObject * filterObj)設置self.keyIsPressed狀態篩選您定義的QEvent.KeyPress。

這是使用QApplication.keyboardModifiers一個例子：

#!/usr/bin/env python 
#-*- coding:utf-8 -*- 

import os 

import sip 
sip.setapi('QString', 2) 
sip.setapi('QVariant', 2) 

from PyQt4.QtCore import * 
from PyQt4.QtGui import * 

class droppableLabel(QLabel): 
    fileDropped = pyqtSignal(list) 

    def __init__(self, type, parent=None): 
     super(droppableLabel, self).__init__(parent) 
     self.setAcceptDrops(True) 

    def dragEnterEvent(self, event): 
     if event.mimeData().hasUrls: 
      event.accept() 

     else: 
      event.ignore() 

    def dragMoveEvent(self, event): 
     if event.mimeData().hasUrls: 
      event.setDropAction(Qt.CopyAction) 
      event.accept() 

     else: 
      event.ignore() 

    def dropEvent(self, event): 
     if event.mimeData().hasUrls: 
      event.setDropAction(Qt.CopyAction) 
      event.accept() 
      links = [] 
      for url in event.mimeData().urls(): 
       links.append(str(url.toLocalFile())) 

      self.fileDropped.emit(links) 

     else: 
      event.ignore() 

class droppableWidget(QWidget): 
    def __init__(self, parent=None): 
     super(droppableWidget, self).__init__(parent) 

     self.label = droppableLabel(self) 
     self.label.fileDropped.connect(self.on_label_fileDropped) 
     self.label.setText("Press CTRL/SHIFT/None and drop some files here") 
     self.label.setMinimumSize(QSize(40, 100)) 

     self.verticalLayout = QVBoxLayout(self) 
     self.verticalLayout.addWidget(self.label) 
     self.verticalLayout.setMargin(0) 

    @pyqtSlot(list) 
    def on_label_fileDropped(self, fileNames): 
     droppedFiles = [ fileName 
          for fileName in fileNames 
          if os.path.exists(fileName) 
          ] 

     if droppedFiles: 
      keyModifiers = QApplication.keyboardModifiers() 
      if keyModifiers == Qt.ShiftModifier: 
       print "SHIFT" 
       formatter = "\n"     

      elif keyModifiers == Qt.ControlModifier: 
       print "CTRL" 
       formatter = "," 

      else: 
       print "NONE" 
       formatter = "|" 

      self.label.setText(formatter.join(droppedFiles)) 

if __name__ == "__main__": 
    import sys 

    app = QApplication(sys.argv) 
    main = droppableWidget() 
    main.show() 
    sys.exit(app.exec_())