Pyqt5 可拖动 QPushButton

Question

我有这个关于如何拖动和移动 QPushButton 的示例代码。该代码的唯一问题是，当您拖动按钮并释放它时，按钮状态保持为选中状态。

谁能帮我更改代码，以便在拖动按钮并释放按钮状态后自动取消选中。所以，我不必单击它来取消选中它。

from PyQt5.QtWidgets import QApplication, QWidget, QPushButton
from PyQt5.QtCore import Qt

class DragButton(QPushButton):

    def mousePressEvent(self, event):
        self.__mousePressPos = None
        self.__mouseMovePos = None
        if event.button() == Qt.LeftButton:
            self.__mousePressPos = event.globalPos()
            self.__mouseMovePos = event.globalPos()

        super(DragButton, self).mousePressEvent(event)

    def mouseMoveEvent(self, event):
        if event.buttons() == Qt.LeftButton:
            # adjust offset from clicked point to origin of widget
            currPos = self.mapToGlobal(self.pos())
            globalPos = event.globalPos()
            diff = globalPos - self.__mouseMovePos
            newPos = self.mapFromGlobal(currPos + diff)
            self.move(newPos)

            self.__mouseMovePos = globalPos

        super(DragButton, self).mouseMoveEvent(event)

    def mouseReleaseEvent(self, event):
        if self.__mousePressPos is not None:
            moved = event.globalPos() - self.__mousePressPos 
            if moved.manhattanLength() > 3:
                event.ignore()
                return

        super(DragButton, self).mouseReleaseEvent(event)

def clicked():
    print ("click as normal!")

if __name__ == "__main__":
    app = QApplication([])
    w   = QWidget()
    w.resize(800,600)

    button = DragButton("Drag", w)
    button.clicked.connect(clicked)

    w.show()
    app.exec_() 

Answer 1

你在 mouseReleaseEvent 中return，这意味着你没有让按钮知道它实际上收到了鼠标释放，从而保持按下状态。

def mouseReleaseEvent(self, event):
    if self.__mousePressPos is not None:
        moved = event.globalPos() - self.__mousePressPos 
        if moved.manhattanLength() > 3:
            event.ignore()
            return # <-- the problem is here!

    super(DragButton, self).mouseReleaseEvent(event)

如果您将鼠标移动几个像素（低于曼哈顿长度），您可以看到它的行为正确，因此您必须完全删除该 if 块，或者在返回之前调用 self.setDown(False) 如果您想要避免发送clicked 信号。