QML的FileDialog设置标题从C++代码

Question

我有以下QML文件：

import QtQuick 2.2 
import QtQuick.Dialogs 1.2 

FileDialog 
{ 
property string myTitle: "Select file to open" 
property string myfilter: "All files (*)" 

id: fileDialog 
objectName: "fileDialogObj" 
title: myTitle 
folder: shortcuts.home 
sidebarVisible : true 
nameFilters: [ myfilter ] 
onAccepted: 
{ 
    close() 
} 
onRejected: 
{ 
    close() 
} 
Component.onCompleted: visible = true 
} 

我想设置从C++代码的title财产。我有一些代码看起来像：

QQmlEngine engine; 
QQmlComponent component(&engine); 
component.loadUrl(QUrl(QStringLiteral("qrc:/qml/my_file_dialog.qml"))); 
QObject* object = component.create(); 
object->setProperty("myTitle", "Open file!"); 

标题具有财产myTitle的初始值（Select file to open）并不会改变对Open file!

我在做什么错？

UPDATE 我也试着直接从C++代码更新标题。

考虑到我有对话框对象，我更新了瓷砖这样的：

QQmlProperty::write(dialog, "title", "testing title"); 

而且也是这样：

dialog->setProperty("title", "testing title"); 

文件对话框的产权未设置。

正如@Tarod在他的回答中提到的，这似乎是一个错误。

或者我错过了什么？

Answer 1

这似乎是一个错误，因为下一个代码工作，如果我们设置

title = "xxx"

，而不是

title = myTitle

此外，您还可以查看其他属性正确更新。即sidebarVisible

的main.cpp

#include <QGuiApplication> 
#include <QQmlApplicationEngine> 
#include <QQmlComponent> 
#include <QQmlProperty> 
#include <QDebug>  

int main(int argc, char *argv[]) 
{ 
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling); 
    QGuiApplication app(argc, argv); 

    QQmlEngine engine; 
    QQmlComponent component(&engine, QUrl(QLatin1String("qrc:/main.qml"))); 
    QObject *object = component.create(); 

    QObject *fileDialog = object->findChild<QObject*>("fileDialogObj"); 

    if (fileDialog) 
    { 
     fileDialog->setProperty("myTitle", "new title"); 
     fileDialog->setProperty("sidebarVisible", true); 
     qDebug() << "Property value:" << QQmlProperty::read(fileDialog, "myTitle").toString(); 
    } else 
    { 
     qDebug() << "not here"; 
    } 

    return app.exec(); 
} 

main.qml

import QtQuick 2.7 
import QtQuick.Controls 2.0 
import QtQml 2.2 
import QtQuick.Dialogs 1.2 

Item { 
    FileDialog 
    { 
     property string myTitle: fileDialog.title 
     property string myfilter: "All files (*)" 

     id: fileDialog 
     objectName: "fileDialogObj" 
     title: "Select file to open" 
     folder: shortcuts.home 
     sidebarVisible : true 
     nameFilters: [ myfilter ] 

     onAccepted: 
     { 
      close() 
     } 
     onRejected: 
     { 
      close() 
     } 
     Component.onCompleted: 
     { 
      visible = true 
     } 
     onMyTitleChanged: 
     { 
      console.log("The next title will be: " + myTitle) 
      title = myTitle 
     } 
    } 
}