Question

好的，我已经设法使用PyQt5和QML进行CircularGauge加载。这是我的QML：

import QtQuick 2.0
import QtQuick.Controls 1.4
import QtQuick.Controls.Styles 1.4
import QtQuick.Extras 1.4
import QtQuick.Extras.Private 1.0

Rectangle {
     width: 300
     height: 300
     color: "#000000"

     CircularGauge {
          property real gauge_value: 10000.0
          anchors.centerIn: parent
          value: gauge_value
          maximumValue: 10000.0  // Largest Value
          minimumValue: 0.0       // Smallest Value
          style: CircularGaugeStyle {
               id: style
               tickmarkStepSize: 1000.0 // Tick Marks

               tickmark: Rectangle {
                    visible: styleData.value < 8000 || styleData.value % 1000 == 0
                    implicitWidth: outerRadius * 0.02
                    antialiasing: true
                    implicitHeight: outerRadius * 0.06
                    color: styleData.value >= 8000 ? "#ff0000" : "#ff0000"
               }

               minorTickmark: Rectangle {
                    visible: styleData.value < 8000
                    implicitWidth: outerRadius * 0.01
                    antialiasing: true
                    implicitHeight: outerRadius * 0.03
                    color: "#ff0000"
               }

               tickmarkLabel:  Text {
                    font.pixelSize: Math.max(6, outerRadius * 0.1)
                    text: styleData.value
                    color: styleData.value >= 8000 ? "#ff0000" : "#ff0000"
                    antialiasing: true
               }

               needle: Rectangle {
                    y: outerRadius * 0.15
                    implicitWidth: outerRadius * 0.03
                    implicitHeight: outerRadius * 1.1
                    antialiasing: true
                    color: "#ff0000"
               }

               foreground: Item {
                    Rectangle {
                         width: outerRadius * 0.2
                         height: width
                         radius: width / 2
                         color: "#b2b2b2"
                         anchors.centerIn: parent
                    }
               }
          }
     }
}

现在是我的Python脚本

import sys
import time
from PyQt5.QtCore import QObject, QUrl, Qt, pyqtProperty
from PyQt5.QtWidgets import QApplication
from PyQt5.QtQml import QQmlApplicationEngine, qmlRegisterType
from PyQt5 import QtCore, QtGui
from PyQt5.QtQuick import QQuickView

if __name__ == "__main__":

     app = QApplication(sys.argv)
     view = QQuickView()
     view.setSource(QUrl('full_gauge.qml'))
     engine = view.engine()
     rot = 4000.0
     engine.rootContext().setContextProperty('gauge_value', rot)
     view.show()
     rot = 0.0
     engine.rootContext().setContextProperty('gauge_value', rot)
     view.update()
     view.show()
     sys.exit(app.exec_())

现在我得到的是：

显然我的代码正确地绘制了图片，但我没有改变代码的值。从我可以告诉我post我可能需要定义一个类？对不起还是一点Python新手。真正伟大的是，如果我可以通过各种值来获得仪表周期。

更新：所以从其他帖子我发现我需要上课：

 class Tachometer(QObject):
      def __init__(self, parent=None):
           super().__init__(parent)
           # Initialise the value of the properties.
           self._rpm_value = rpm_value

      # Define the getter of the 'rpm_value' property.  The C++ type and
      # Python type of the property is float.
      @pyqtProperty(float)
      def rpm_value(self):
           print("Getting value")
           return self._rpm_value

      # Define the setter of the 'rpm_value' property.
      @rpm_value.setter
      def rpm_value(self, value):
           print("Setting value")
           self._rpm_value = value

现在不知怎的，我需要将它与我的QML联系起来。但是，我在这里感到困惑。首先，我需要将其添加到我的QML中吗？其次，我如何将其与我的代码联系起来，我最好的尝试是：

 if __name__ == "__main__":
      # Create the application instance
      app = QApplication(sys.argv)
      # Register the Python type.  Its URI is 'Tachometer', it's v1.0 and the type
      # will be called 'Tachometer' in QML.
      qmlRegisterType(Tachometer, 'Tachometer', 1, 0, 'Tachometer')
      # Create a QML engine.
      view = QQuickView()
      engine = view.engine()
      # Create a component factory and load the QML script.
      component = QQmlComponent(engine)
      #component.loadUrl(QUrl('full_gauge.qml'))
      view.setSource(QUrl('full_gauge.qml'))
      # draw the window
      view.show()

我在这里缺少什么？

Answer 1

好的，正如我已经说过的那样，你正在改变一个错误项目的属性。实际上，你试图改变黑色矩形的属性gauge_value女巫实际上是根项目，并且根本没有这样的属性。

我不知道如何在Python中这样做但在C ++中我会这样做：

QObject *root = dynamic_cast<QObject *>(engine.rootObjects().first());
QObject *gauge = root->findChild<QObject *>("gauge");
gauge->setProperty("gauge_value",5000);

您的CircularGauge应该是这样的：

CircularGauge {
    objectName: "gauge" // << add this
    property real gauge_value: 10000.0
    // the code here
}

Answer 2

好的，我想出了如何更改价值。一个问题是拼写错误，但否则这似乎有效。

QML

import QtQuick 2.0
import QtQuick.Controls 1.4
import QtQuick.Controls.Styles 1.4
import QtQuick.Extras 1.4
import QtQuick.Extras.Private 1.0

Rectangle {
    width: 300
    height: 300
    color: "#000000"

    CircularGauge {
        objectName: "test_gauge"
        property real gauge_value: 10000.0
        anchors.centerIn: parent
        value: gauge_value
        maximumValue: 10000.0  // Largest Value
        minimumValue: 0.0       // Smallest Value
        style: CircularGaugeStyle {
            id: style
            tickmarkStepSize: 1000.0 // Tick Marks

            tickmark: Rectangle {
                visible: styleData.value < 8000 || styleData.value % 1000 == 0
                implicitWidth: outerRadius * 0.02
                antialiasing: true
                implicitHeight: outerRadius * 0.06
                color: styleData.value >= 8000 ? "#ff0000" : "#ff0000"
            }

           minorTickmark: Rectangle {
                visible: styleData.value < 8000
                implicitWidth: outerRadius * 0.01
                antialiasing: true
                implicitHeight: outerRadius * 0.03
                color: "#ff0000"
           }

           tickmarkLabel:  Text {
                font.pixelSize: Math.max(6, outerRadius * 0.1)
                text: styleData.value
                color: styleData.value >= 8000 ? "#ff0000" : "#ff0000"
                antialiasing: true
           }

           needle: Rectangle {
                y: outerRadius * 0.15
                implicitWidth: outerRadius * 0.03
                implicitHeight: outerRadius * 1.1
                antialiasing: true
                color: "#ff0000"
           }

           foreground: Item {
                Rectangle {
                     width: outerRadius * 0.2
                     height: width
                     radius: width / 2
                     color: "#b2b2b2"
                     anchors.centerIn: parent
                }
           }
      }
 }
}

的Python

#!/usr/bin/env python3
import sys
import time
from PyQt5.QtCore import QObject, QUrl, Qt, pyqtProperty, pyqtSignal
from PyQt5.QtWidgets import QApplication
from PyQt5.QtQml import QQmlApplicationEngine, qmlRegisterType, QQmlEngine, QQmlComponent
from PyQt5 import QtCore, QtGui
from PyQt5.QtQuick import QQuickView

if __name__ == "__main__":
    app = QApplication(sys.argv)
    view = QQuickView()
    view.setSource(QUrl('full_gauge.qml'))
    gauge=view.findChild(QObject,'test_gauge')
    gauge.setProperty('gauge_value',4500)
    view.show()
    sys.exit(app.exec_())

现在我可以设置＆＃39;值＆＃39;规格。

使用pyqt5更改CircularGauge

2 个答案: