来自QtSharp的QML中的SetProperty

Question

我使用QtSharp在单独的"window“中显示一个QWidget。现在，我的问题是如何更新property (在我的示例projector.name中)，它是从后面的代码在qml中定义的。

代码背后

public partial class MainWindow : Window
{
    int count = 0;
    private Projector _Projector;

    public MainWindow()
    {
        InitializeComponent();
        Loaded += _OnLoaded;
    }

    private void _OnLoaded(object sender, RoutedEventArgs routedEventArgs)
    {
        unsafe
        {
            var qtApp = new QApplication(ref count, null);
        }
        _Projector = new Projector();

    }

    private void ButtonBase_OnClickOpen(object sender, RoutedEventArgs e)
    {
        _Projector.Show();
    }

    private void ButtonBase_OnClickPaint(object sender, RoutedEventArgs e)
    {
        _Projector.X += 10;
        _Projector.Y += 5;
        if(_Projector.QuickWidget.Hidden)
            _Projector.QuickWidget.Show();
        else
        {
            _Projector.QuickWidget.Hide();                
        }
        _Projector.Paint();
    }
}

public class Projector : QWidget
{
    public int X { get; set; } = 123;
    public int Y { get; set; } = 12;
    public QQuickWidget QuickWidget;

    public Projector()
    {
        WindowTitle = "Paint Demo";

        Resize(800, 800);
        Show();

        QuickWidget = new QQuickWidget(this);
        QuickWidget.Source = new QUrl(@"\QML\main.qml");
        QuickWidget.RootContext.SetContextProperty("projector", this);            
        QuickWidget.SetProperty("name", new QVariant("Hello"));
        QuickWidget.resizeMode = QQuickWidget.ResizeMode.SizeRootObjectToView;
        QuickWidget.Geometry = new QRect(50, 10, 100, 300);
        QuickWidget.UpdatesEnabled = true;
        QuickWidget.Show();
    }

    protected override void OnPaintEvent(QPaintEvent e)
    {
        base.OnPaintEvent(e);
        var painter = new QPainter(this);
        painter.SetRenderHint ( QPainter.RenderHint.Antialiasing );

        DrawPatternsEx ( painter );
        painter.End();
    }

    void DrawPatternsEx(QPainter ptr)
    {
        ptr.SetPen(PenStyle.SolidLine);
        ptr.SetPen(QColor.FromRgb(255,0,0));

        ptr.DrawLine(0, Y, Size.Width, Y);
        ptr.DrawLine(X, 0, X, Size.Height);
    }

    public void Paint()
    {
        QuickWidget.Update();
        Update();
    }
}

main.qml

import QtQuick 2.4
import QtQuick.Layouts 1.1

Rectangle {
    id: root
    width: 300
    height: 600

    Rectangle {
        id: headerSchritt
        width: 300
        height: 50
        color: "#ff8629"
        anchors.right: parent.right
        anchors.rightMargin: 0
        anchors.left: parent.left
        anchors.leftMargin: 0
        anchors.top: parent.top
        anchors.topMargin: 0

        Text {
            y: 9
            text: qsTr("Schritt:")
            anchors.left: parent.left
            anchors.leftMargin: 10
            anchors.verticalCenter: parent.verticalCenter
            font.bold: false
            font.pixelSize: projector.fontSize
        }
    }


    Text {
        id: currentStepLabel
        anchors.top: headerSchritt.bottom
        anchors.left: parent.left
        anchors.margins: 10
        text: qsTr("Aktuell:")
        font.pixelSize: projector.fontSize
    }
    Text {
        id: currentStep
        font.pixelSize: projector.fontSize
        text: projector.currentStep
        font.bold: true
        anchors.top: headerSchritt.bottom
        anchors.right: parent.right
        anchors.margins: 10
    }

    Text {
        id: numStepsLabel
        anchors.top: currentStep.bottom
        anchors.left: parent.left
        anchors.margins: 10
        text: qsTr("Gesamt:")
        font.pixelSize: projector.fontSize
    }
    Text {
        id: numSteps
        font.pixelSize: projector.fontSize
        text: projector.numSteps
        anchors.top: currentStep.bottom
        anchors.right: parent.right
        anchors.margins: 10
    }

    Rectangle {
        id: headerComponent
        height: 50
        color: "#ff8629"
        anchors.right: parent.right
        anchors.rightMargin: 0
        anchors.left: parent.left
        anchors.leftMargin: 0
        anchors.top: numSteps.bottom
        anchors.topMargin: 10

        Text {
            y: 9
            text: qsTr("Komponente:")
            anchors.left: parent.left
            anchors.leftMargin: 10
            anchors.verticalCenter: parent.verticalCenter
            font.pixelSize: projector.fontSize
        }
    }

    Text {
        id: name
        text: projector.name
        wrapMode: Text.WrapAtWordBoundaryOrAnywhere
        font.family: "Courier"
        anchors.top: headerComponent.bottom
        anchors.right: parent.right
        anchors.left: parent.left
        anchors.margins: 10
        font.italic: false
        font.pixelSize: projector.fontSize
    }

    Text {
        id: componentCode
        text: projector.cCode
        wrapMode: Text.WrapAtWordBoundaryOrAnywhere
        anchors.top: name.bottom
        anchors.right: parent.right
        anchors.left: parent.left
        anchors.margins: 10
        font.bold: true
        font.pixelSize: projector.fontSize
    }

    Text {
        id: componentName
        font.pixelSize: projector.fontSize
        text: projector.cName
        wrapMode: Text.WrapAtWordBoundaryOrAnywhere
        anchors.top: componentCode.bottom
        anchors.right: parent.right
        anchors.left: parent.left
        anchors.margins: 10
    }

    Image {
        id: componentPicture
        width: height
        anchors.bottom: parent.bottom
        anchors.top: componentName.bottom
        anchors.margins: 10
        anchors.horizontalCenter: parent.horizontalCenter
        source: "image://componentpictures/" + projector.cId
        fillMode: Image.PreserveAspectFit
    }

}

在Qt中，我必须定义一个在QtSharp库中不可用的Q_PROPERTY。也许我只是漏掉了什么？

Answer 1

实际上，遵循http://doc.qt.io/qt-5/qtqml-cppintegration-interactqmlfromcpp.html的指导方针是可能的。

您必须在根QML对象中定义一个属性，如Mohammad (此处为componentName)指出的那样：

import QtQuick 2.4
import QtQuick.Layouts 1.1

Rectangle {
    id: root
    width: 300
    height: 600

    property string componentName: "test"

    Rectangle {
        id: headerSchritt
        width: 300
        height: 50
        color: "#ff8629"
        anchors.right: parent.right
        anchors.rightMargin: 0
        anchors.left: parent.left
        anchors.leftMargin: 0
        anchors.top: parent.top
        anchors.topMargin: 0

        Text {
            y: 9
            text: qsTr("Schritt:")
            anchors.left: parent.left
            anchors.leftMargin: 10
            anchors.verticalCenter: parent.verticalCenter
            font.bold: false
            font.pixelSize: projector.fontSize
        }
    }


    Text {
        id: currentStepLabel
        anchors.top: headerSchritt.bottom
        anchors.left: parent.left
        anchors.margins: 10
        text: qsTr("Aktuell:")
        font.pixelSize: projector.fontSize
    }
    Text {
        id: currentStep
        font.pixelSize: projector.fontSize
        text: projector.currentStep
        font.bold: true
        anchors.top: headerSchritt.bottom
        anchors.right: parent.right
        anchors.margins: 10
    }

    Text {
        id: numStepsLabel
        anchors.top: currentStep.bottom
        anchors.left: parent.left
        anchors.margins: 10
        text: qsTr("Gesamt:")
        font.pixelSize: projector.fontSize
    }
    Text {
        id: numSteps
        font.pixelSize: projector.fontSize
        text: projector.numSteps
        anchors.top: currentStep.bottom
        anchors.right: parent.right
        anchors.margins: 10
    }

    Rectangle {
        id: headerComponent
        height: 50
        color: "#ff8629"
        anchors.right: parent.right
        anchors.rightMargin: 0
        anchors.left: parent.left
        anchors.leftMargin: 0
        anchors.top: numSteps.bottom
        anchors.topMargin: 10

        Text {
            y: 9
            text: qsTr("Komponente:")
            anchors.left: parent.left
            anchors.leftMargin: 10
            anchors.verticalCenter: parent.verticalCenter
            font.pixelSize: projector.fontSize
        }
    }

    Text {
        id: name
        text: root.componentName
        wrapMode: Text.WrapAtWordBoundaryOrAnywhere
        font.family: "Courier"
        anchors.top: headerComponent.bottom
        anchors.right: parent.right
        anchors.left: parent.left
        anchors.margins: 10
        font.italic: false
        font.pixelSize: projector.fontSize
    }

    Text {
        id: componentCode
        text: projector.cCode
        wrapMode: Text.WrapAtWordBoundaryOrAnywhere
        anchors.top: name.bottom
        anchors.right: parent.right
        anchors.left: parent.left
        anchors.margins: 10
        font.bold: true
        font.pixelSize: projector.fontSize
    }

    Text {
        id: componentName
        font.pixelSize: projector.fontSize
        text: projector.cName
        wrapMode: Text.WrapAtWordBoundaryOrAnywhere
        anchors.top: componentCode.bottom
        anchors.right: parent.right
        anchors.left: parent.left
        anchors.margins: 10
    }

    Image {
        id: componentPicture
        width: height
        anchors.bottom: parent.bottom
        anchors.top: componentName.bottom
        anchors.margins: 10
        anchors.horizontalCenter: parent.horizontalCenter
        source: "image://componentpictures/" + projector.cId
        fillMode: Image.PreserveAspectFit
    }
}

然后，通过调用RootObject，可以通过包含在QQuickWidget中的Info.RootObject.SetProperty("componentName", "lorem ipsum");访问已定义的属性。

public partial class MainWindow : Window
{
    int count = 0;
    private Projector _Projector;

    public MainWindow()
    {
        InitializeComponent();
        Loaded += _OnLoaded;
    }

    private void _OnLoaded(object sender, RoutedEventArgs routedEventArgs)
    {
        unsafe
        {
            var qtApp = new QApplication(ref count, null);
        }
        _Projector = new Projector();

    }

    private void ButtonBase_OnClickOpen(object sender, RoutedEventArgs e)
    {
        _Projector.Show();
    }

    private void ButtonBase_OnClickPaint(object sender, RoutedEventArgs e)
    {
        _Projector.X += 10;
        _Projector.Y += 5;
        if(_Projector.Info.Hidden)
            _Projector.Info.Show();
        else
        {
            _Projector.Info.Hide();                
        }
        _Projector.Paint();
    }
}

public class Projector : QWidget
{
    public int X { get; set; } = 123;
    public int Y { get; set; } = 12;

    public QQuickWidget Info;
    public QObject qmlRoot;

    public Projector()
    {
        WindowTitle = "Paint Demo";
        Palette.SetColor(QPalette.ColorRole.Background, QColor.FromRgb(0,0,0));

        Resize(800, 800);
        Show();

        Info = new QQuickWidget(this);
        Info.Source = new QUrl(@"\QML\main.qml");
        Info.RootObject.SetProperty("componentName", "lorem ipsum");
        Info.resizeMode = QQuickWidget.ResizeMode.SizeRootObjectToView;
        Info.Geometry = new QRect(50, 10, 100, 300);
        Info.Show();
    }

    protected override void OnPaintEvent(QPaintEvent e)
    {
        base.OnPaintEvent(e);
        var painter = new QPainter(this);
        painter.SetRenderHint ( QPainter.RenderHint.Antialiasing );

        DrawPatternsEx ( painter );
        painter.End();
    }

    void DrawPatternsEx(QPainter ptr)
    {
        ptr.SetPen(PenStyle.SolidLine);
        ptr.SetPen(QColor.FromRgb(255,0,0));

        ptr.DrawLine(0, Y, Size.Width, Y);
        ptr.DrawLine(X, 0, X, Size.Height);
    }

    public void Paint()
    {
        Update();
    }
}

Answer 2

似乎它实际上还不受支持(https://github.com/ddobrev/QtSharp/issues/74)：

恐怕你现在不行。还没有添加与QML的交互。 我当然希望它会接近，但我不知道。与QML的集成是必须的，没有其他的意见，但我只是担心在过去的一个月里，我实在无法抽出任何时间在绑定上。我还需要完成一些模板的工作，在此之前我不会从QML开始。所以任何帮助都是受欢迎的。例如，它将帮助我知道如何在理论上做到这一点。我知道PyQt是通过手工修改Qt的元对象系统来做到这一点的，但我仍未了解细节。