我的主窗口有一个qml GUI。我刚创建了一个qt quick2应用程序，并将主窗口的qml GUI复制并粘贴到main.qml。当我运行应用程序时，它显示空白窗口，以下是我的qml日志：
QML debugging is enabled. Only use this in a safe environment.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
Both point size and pixel size set. Using pixel size.
file:///home/khajvah/build-convQML-Desktop_Qt_5_1_0_GCC_64bit-Debug/qml/convQML/main.qml:99:9: QML Text: Cannot anchor to an item that isn't a parent or sibling.
file:///home/khajvah/build-convQML-Desktop_Qt_5_1_0_GCC_64bit-Debug/qml/convQML/main.qml:31:9: QML BasicButton: Cannot anchor to an item that isn't a parent or sibling.
file:///home/khajvah/Qt5.1.0/5.1.0/gcc_64/qml/QtQuick/Controls/Styles/Base/ToolButtonStyle.qml:73:9: QML Image: Cannot open: file:///home/khajvah/build-convQML-Desktop_Qt_5_1_0_GCC_64bit-Debug/logout-512.png
file:///home/khajvah/Qt5.1.0/5.1.0/gcc_64/qml/QtQuick/Controls/Styles/Base/ToolButtonStyle.qml:73:9: QML Image: Cannot open: file:///home/khajvah/build-convQML-Desktop_Qt_5_1_0_GCC_64bit-Debug/console.ico
file:///home/khajvah/Qt5.1.0/5.1.0/gcc_64/qml/QtQuick/Controls/Styles/Base/ToolButtonStyle.qml:73:9: QML Image: Cannot open: file:///home/khajvah/build-convQML-Desktop_Qt_5_1_0_GCC_64bit-Debug/mod.png
QQuickView only supports loading of root objects that derive from QQuickItem.
If your example is using QML 2, (such as qmlscene) and the .qml file you
loaded has 'import QtQuick 1.0' or 'import Qt 4.7', this error will occur.
To load files with 'import QtQuick 1.0' or 'import Qt 4.7', use the
QDeclarativeView class in the Qt Quick 1 module.
以下是我的qml文件：
import QtQuick 2.1
import QtQuick.Controls 1.0
import QtQuick.Window 2.0
ApplicationWindow {
id: applicationwindow1
title: qsTr("Converter")
width: 500
//height: 600
// menuBar: MenuBar {
// }
ToolBar {
id: tool_bars
x: 0
y: 0
width: applicationwindow1.width
height: 39
clip: true
smooth: false
opacity: 1
transformOrigin: Item.Center
ToolButton {
id: modify
y: 1
scale: 1
anchors.right: tool_bars.left
iconSource: "../../mod.png"
}
ToolButton {
id: consolebtn
x: 32
y: 1
scale: 1
anchors.left: modify.right
anchors.leftMargin: 6
iconSource: "../../console.ico"
}
ToolButton {
id: exit;
x: 75
y: 1
scale: 1
anchors.left: consolebtn.right;
anchors.leftMargin: 6
iconSource: "../../logout-512.png"
}
}
GroupBox {
id: group_box1
x: 0
y: 30
width: 500
height: 136
anchors.top: tool_bars.bottom
anchors.topMargin: -9
anchors.left: parent.left
anchors.leftMargin: 0
anchors.right: parent.right
anchors.rightMargin: 0
ComboBox {
id: typebox
anchors.left: text1.right
anchors.leftMargin: 5
width: 70
height: 23
anchors.top: parent.top
anchors.topMargin: 37
}
Text {
id: text1
anchors.left: group_box1.left
anchors.leftMargin: 5
text: "Type:"
anchors.top: parent.top
anchors.topMargin: 41
font.italic: true
style: Text.Normal
font.pointSize: 12
font.pixelSize: 12
}
ComboBox {
id: frombox
x: 205
anchors.left: text2.right
anchors.leftMargin: 8
width: 70
height: 23
anchors.top: parent.top
anchors.topMargin: 37
}
Text {
id: text2
x: 189
anchors.leftMargin: 20
text: "From:"
anchors.top: parent.top
anchors.topMargin: 41
anchors.horizontalCenterOffset: -32
anchors.horizontalCenter: parent.horizontalCenter
font.italic: true
style: Text.Normal
font.pointSize: 12
font.pixelSize: 12
}
ComboBox {
id: tobox
x: 412
anchors.right: parent.right
anchors.rightMargin: 5
width: 70
height: 23
anchors.top: parent.top
anchors.topMargin: 37
}
Text {
id: text3
x: 0
text: "To:"
anchors.top: parent.top
anchors.topMargin: 41
anchors.right: tobox.left
anchors.rightMargin: 5
font.italic: true
style: Text.Normal
font.pointSize: 12
font.pixelSize: 12
}
TextField {
id: text_field1
y: 78
width: 197
height: 22
anchors.bottom: parent.bottom
anchors.bottomMargin: 15
anchors.left: parent.left
anchors.leftMargin: 5
placeholderText: "Input"
}
TextField {
id: text_field2
x: 293
y: 78
width: 186
height: 22
anchors.bottom: parent.bottom
anchors.bottomMargin: 15
anchors.right: parent.right
anchors.rightMargin: 5
readOnly: true
placeholderText: "Result"
}
}
TextArea {
id: text_area1
x: 0
y: 178
width: 500
height: 80
anchors.left: parent.left
anchors.leftMargin: 0
anchors.right: parent.right
anchors.rightMargin: 0
anchors.top: group_box1.bottom
anchors.topMargin: 12
anchors.bottom: addlogbtn.top
anchors.bottomMargin: 5
}
Button {
id: addlogbtn
x: 7
y: 212
width: 110
height: 23
text: "Add to Log"
anchors.bottom: parent.bottom
anchors.bottomMargin: 5
anchors.left: parent.left
anchors.leftMargin: 7
}
Button {
id: button1
x: 195
y: 212
width: 118
height: 23
text: "Export"
anchors.horizontalCenter: parent.horizontalCenter
anchors.bottom: parent.bottom
anchors.bottomMargin: 5
}
Button {
id: button2
x: 359
y: 212
width: 117
height: 23
text: "Clear"
anchors.right: parent.right
anchors.rightMargin: 7
anchors.bottom: parent.bottom
anchors.bottomMargin: 5
}
}
并自动生成main.cpp：
#include <QtGui/QGuiApplication>
#include "qtquick2applicationviewer.h"
int main(int argc, char *argv[])
{
QGuiApplication app(argc, argv);
QtQuick2ApplicationViewer viewer;
viewer.setMainQmlFile(QStringLiteral("qml/convQML/main.qml"));
viewer.showExpanded();
return app.exec();
}
为什么这不起作用的任何想法？我是qml的新手，我真的很困惑它是如何连接到c ++的。
答案 0 :(得分：17)
您绝对可以使用ApplicationWindow，但需要使用QQmlApplicationEngine，并且需要明确显示您的顶层窗口。您可以在another answer中看到完整的示例。下面只是一个适合您的main.cpp文件。
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QQuickWindow>
int main(int argc, char *argv[])
{
QGuiApplication app(argc, argv);
QQmlApplicationEngine engine;
engine.load(QUrl("qml/convQML/main.qml"));
QObject *topLevel = engine.rootObjects().value(0);
QQuickWindow *window = qobject_cast<QQuickWindow *>(topLevel);
window->show();
return app.exec();
}