python - PySide2 - 如何在标签上显示 "count of unread"？

Question

我知道当我触发编辑事件时，我会将其添加到计数器中，但是如何将其显示在标签上？

或者，这实际上是在同一个 block 中显示的两个标签吗？

Answer 1

正如评论中所说，您必须使用 QPixmap 创建图像，然后使用 QPainter 绘制蓝色圆圈和文本，并将最终图像设置为按钮的图标。

下面，您将找到一个工作示例，其中有 2 个按钮用于增加/减少“未读”值。

每次更改此值时，都会发出 unreadCountChanged() 信号。

图像在 unreadCountChanged 插槽上创建并设置为按钮图标。

from PyQt4 import QtCore, QtGui
import sys


class MyApplication(QtGui.QMainWindow):
    def __init__(self):
        super(MyApplication, self).__init__()
        self.unreadCount = 0

        self.setupUi()
        self.connect(self, QtCore.SIGNAL("unreadCountChanged()"), self.unreadCountChanged)

    def setupUi(self):
        self.pixmapBtn = QtGui.QPushButton(self)
        self.pixmapBtn.setGeometry(QtCore.QRect(0, 0, 41, 41))
        icon = QtGui.QIcon()
        icon.addPixmap(QtGui.QPixmap("play.png"), QtGui.QIcon.Normal, QtGui.QIcon.Off)
        self.pixmapBtn.setIconSize(QtCore.QSize(32, 32))
        self.pixmapBtn.setIcon(icon)

        upBtn = QtGui.QPushButton("+", self)
        upBtn.setGeometry(QtCore.QRect(60, 0, 41, 41))
        self.connect(upBtn, QtCore.SIGNAL("clicked()"), self.onUpClicked)

        downBtn = QtGui.QPushButton("-", self)
        downBtn.setGeometry(QtCore.QRect(60, 50, 41, 41))
        self.connect(downBtn, QtCore.SIGNAL("clicked()"), self.onDownClicked)

        self.unreadLabel = QtGui.QLabel(self)
        self.unreadLabel.setText("Count: {}".format(self.unreadCount))
        self.unreadLabel.setGeometry(QtCore.QRect(5, 60, 51, 16))

        self.resize(200, 200)

    def onUpClicked(self):
        self.unreadCount += 1
        self.emit(QtCore.SIGNAL("unreadCountChanged()"))

    def onDownClicked(self):
        if self.unreadCount > 0:
            self.unreadCount -= 1
        self.emit(QtCore.SIGNAL("unreadCountChanged()"))

    def unreadCountChanged(self):
        self.unreadLabel.setText("Count: {}".format(self.unreadCount))

        pixmap = QtGui.QPixmap("play.png")
        if self.unreadCount > 0:
            painter = QtGui.QPainter()
            painter.begin(pixmap)
            painter.setBrush(QtCore.Qt.blue)  # Set the circle color
            center = QtCore.QPoint(90, 90)
            painter.drawEllipse(center, 40, 40)
            font = painter.font()
            font.setPointSize(30)
            pen = painter.pen()
            pen.setColor(QtCore.Qt.white)  # Set the text color
            painter.setPen(pen)
            painter.setFont(font)
            painter.drawText(80, 100, str(self.unreadCount))
            painter.end()

        icon = QtGui.QIcon()
        icon.addPixmap(pixmap, QtGui.QIcon.Normal, QtGui.QIcon.Off)
        self.pixmapBtn.setIcon(icon)


if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    w = MyApplication()
    w.show()
    sys.exit(app.exec_())