QQuickImageProvider PyQt5

Posted 2023-03-30

【中文标题】QQuickImageProvider PyQt5

【英文标题】：

【发布时间】：2017-11-27 01:40:24

【问题描述】：

我尝试使用 QQuickImageProvider 将 QImage 发送到 QML，在 c++ Qt5.9.2 中一切正常，但我尝试使用 PyQt5(5.9.2) 的类似代码，QML 只是说错误： ImageProvider支持Image类型但没有实现requestImage()，其实我实现了requestImage()，这里是我的代码：

ma​​in.py:

from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtQml import *
from PyQt5.QtQuick import *

class MyImageProvider(QQuickImageProvider):
    def __init__(self):
        super(MyImageProvider, self).__init__(QQuickImageProvider.Image) 

    def requestImage(self, p_str, size):
        img = QImage(300, 300, QImage.Format_RGBA8888)
        img.fill(Qt.red)
        return img, img.size()

app = QGuiApplication([])    

viewer = QQuickView()
viewer.engine().addImageProvider("myprovider", MyImageProvider())
viewer.setResizeMode(QQuickView.SizeRootObjectToView)
viewer.setSource(QUrl("example.qml"))
viewer.show()

app.exec()

example.qml:

import QtQuick 2.7

Item 
    id: root
    width: 800
    height: 600
    Image
         // width: 300
         // height: 300
         source: "image://myprovider/test.png"
    

也许 requestImage() 在 python 和 c++ 中有不同的参数和返回值，我确定格式是正确的。参考一些例子，http://nullege.com/codes/search/PyQt5.QtQuick.QQuickImageProvider，我不知道我怎么了。

【参考方案1】：

根据我正在审查的问题是 QQuickView 或 QQmlEngine，这些类已过时。

我推荐你使用QQmlApplicationEngine：

ma​​in.py

import sys
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtQml import *
from PyQt5.QtQuick import *


class MyImageProvider(QQuickImageProvider):
    def __init__(self):
        super(MyImageProvider, self).__init__(QQuickImageProvider.Image)

    def requestImage(self, p_str, size):
        img = QImage(300, 300, QImage.Format_RGBA8888)
        img.fill(Qt.red)
        return img, img.size()


if __name__ == '__main__':
    app = QGuiApplication(sys.argv)

    engine = QQmlApplicationEngine()
    engine.addImageProvider("myprovider", MyImageProvider())
    engine.load(QUrl.fromLocalFile("example.qml"))
    if len(engine.rootObjects()) == -1:
        sys.exit(-1)
    sys.exit(app.exec_())

example.qml

import QtQuick 2.7
import QtQuick.Window 2.2

Window
    visible: true
    width: 640
    height: 480
    Image
         anchors.fill : parent
         source: "image://myprovider/test.png"
    

【参考方案2】：

我遇到了同样的问题。似乎是因为提供者实例在传递给 addImageProvider() 后丢失了。我解决了这个问题，如下所示。

app = QGuiApplication([])    

viewer = QQuickView()
provider = MyImageProvider() # keep this instance during your app running
viewer.engine().addImageProvider("myprovider", provider)
viewer.setResizeMode(QQuickView.SizeRootObjectToView)
viewer.setSource(QUrl("example.qml"))
viewer.show()

app.exec()