QML 获取加载的 qml 的 winId window
QML get the winId of a loaded qml window
我想获取一个qml的winId window。我有以下文件。
main.qml :
import QtQuick 2.5
import QtQuick.Window 2.2
import QtQuick.Controls 1.4
Window {
id: myMainWindow
title: "MyMainWindow"
width: 200
height: 200;
visible: true
Component.onCompleted: {
x = 40
y = 40
}
}
和我的 main.cpp :
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QWindow>
int main(int argc, char *argv[])
{
QGuiApplication app(argc, argv);
QQmlApplicationEngine engine;
qmlRegisterType<FbItem>("fbitem", 1, 0, "FbItem");
engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
QObject* m_rootObject = engine.rootObjects().first();
auto rect_area = m_rootObject->findChild<QWindow*>("myMainWindow"); //the id of the Window in qml
//both lines make the application crash
//HWND hWnd = reinterpret_cast<HWND>(rect_area->winId());
WId wid = rect_area->winId();
return app.exec();
}
崩溃信息是:
The inferior stopped because it triggered an exception.
Stopped in thread 0 by: Exception at 0x13500da, code: 0x0000005: read access violation at: 0x0, flags=0x0 (first chance).
怎么了?如何获取 window 的 winId?
编辑:我们可以看到 rect_area 仍然很糟糕。在编辑中 main.qml :
Window {
id: _component
objectName: "myMainWindow"
...
}
好的,正如我在评论中注意到的那样,您始终必须检查 findChild
返回的值。其次,findChild
通过 objectName
查找,而不是像您错误假设的那样通过 id
查找。
但就您而言,这只是一个建议。您的问题 myMainWindow
已经是根项(即 Window
项),因此 m_rootObject
正是您所需要的。因此,您尝试在项目本身内部搜索项目并有效地获得 null。要获得 Window
你只需要:
QObject* m_rootObject = engine.rootObjects().first();
if(m_rootObject) {
QWindow *window = qobject_cast<QWindow *>(m_rootObject);
if(window) {
WId wid = window->winId();
}
}
当然,这段代码太多了,我只是想表达一下想法。
我想获取一个qml的winId window。我有以下文件。
main.qml :
import QtQuick 2.5
import QtQuick.Window 2.2
import QtQuick.Controls 1.4
Window {
id: myMainWindow
title: "MyMainWindow"
width: 200
height: 200;
visible: true
Component.onCompleted: {
x = 40
y = 40
}
}
和我的 main.cpp :
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QWindow>
int main(int argc, char *argv[])
{
QGuiApplication app(argc, argv);
QQmlApplicationEngine engine;
qmlRegisterType<FbItem>("fbitem", 1, 0, "FbItem");
engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
QObject* m_rootObject = engine.rootObjects().first();
auto rect_area = m_rootObject->findChild<QWindow*>("myMainWindow"); //the id of the Window in qml
//both lines make the application crash
//HWND hWnd = reinterpret_cast<HWND>(rect_area->winId());
WId wid = rect_area->winId();
return app.exec();
}
崩溃信息是:
The inferior stopped because it triggered an exception.
Stopped in thread 0 by: Exception at 0x13500da, code: 0x0000005: read access violation at: 0x0, flags=0x0 (first chance).
怎么了?如何获取 window 的 winId?
编辑:我们可以看到 rect_area 仍然很糟糕。在编辑中 main.qml :
Window {
id: _component
objectName: "myMainWindow"
...
}
好的,正如我在评论中注意到的那样,您始终必须检查 findChild
返回的值。其次,findChild
通过 objectName
查找,而不是像您错误假设的那样通过 id
查找。
但就您而言,这只是一个建议。您的问题 myMainWindow
已经是根项(即 Window
项),因此 m_rootObject
正是您所需要的。因此,您尝试在项目本身内部搜索项目并有效地获得 null。要获得 Window
你只需要:
QObject* m_rootObject = engine.rootObjects().first();
if(m_rootObject) {
QWindow *window = qobject_cast<QWindow *>(m_rootObject);
if(window) {
WId wid = window->winId();
}
}
当然,这段代码太多了,我只是想表达一下想法。