由于导入错误，带工具栏的 ApplicationWindow 无法保存 SwipeView

Question

我正在使用 Qt Opensource 5.10.0 with Qt Creator 4.5.0 based on ArchLinux 64bit. and the docs for ApplicationWindow 说明它需要 QtQuick.Controls 1.4:

import QtQuick 2.10
import QtQuick.Controls 1.4

ApplicationWindow
{
    width: 640
    height: 480

    visible: true

    toolBar: ToolBar
    {
    }   // ToolBar
}   // ApplicationWindow

编译运行正常。现在，我想添加 SwipeView to upper ApplicationWindow, however QtQuickControls 1.4 does not recognize it, as it also states in SwipeView's docs 并要求 import QtQuick.Controls 2.3，所以如果我让 import QtQuick.Controls 1.4 在 main.qml 中：

import QtQuick 2.10
import QtQuick.Controls 1.4

ApplicationWindow
{
    width: 640
    height: 480

    visible: true

    toolBar: ToolBar
    {
    }   // ToolBar

    SwipeView
    {
    }   // SwipeView
}   // ApplicationWindow

我收到错误：

Starting /mnt/projects/build-test12-Desktop_Qt_5_10_0_GCC_64bit-Debug/test12...
QML debugging is enabled. Only use this in a safe environment.
QQmlApplicationEngine failed to load component
qrc:/main.qml:15 SwipeView is not a type

/mnt/projects/build-test12-Desktop_Qt_5_10_0_GCC_64bit-Debug/test12 exited with code 255

如果使用 import QtQuick.Controls 2.3:

import QtQuick 2.10
import QtQuick.Controls 2.3

ApplicationWindow
{
    width: 640
    height: 480

    visible: true

    toolBar: ToolBar
    {
    }   // ToolBar

    SwipeView
    {
    }   // SwipeView
}   // ApplicationWindow

我收到以下错误：

Starting /mnt/projects/build-test12-Desktop_Qt_5_10_0_GCC_64bit-Debug/test12...
QML debugging is enabled. Only use this in a safe environment.
QQmlApplicationEngine failed to load component
qrc:/main.qml:11 Cannot assign to non-existent property "toolBar"

/mnt/projects/build-test12-Desktop_Qt_5_10_0_GCC_64bit-Debug/test12 exited with code 255

现在，如果我包括两个进口：

import QtQuick 2.10
import QtQuick.Controls 1.4
import QtQuick.Controls 2.3

ApplicationWindow
{
    width: 640
    height: 480

    visible: true

    toolBar: ToolBar
    {
    }   // ToolBar

    SwipeView
    {
    }   // SwipeView
}   // ApplicationWindow

我仍然得到：

Starting /mnt/projects/build-test12-Desktop_Qt_5_10_0_GCC_64bit-Debug/test12...
QML debugging is enabled. Only use this in a safe environment.
QQmlApplicationEngine failed to load component
qrc:/main.qml:12 Cannot assign to non-existent property "toolBar"

/mnt/projects/build-test12-Desktop_Qt_5_10_0_GCC_64bit-Debug/test12 exited with code 255

如第二种情况。第一个错误是合乎逻辑的，因为在版本 1.4 中没有 SwipeView，然而，为什么 QtQuick.Controls 2.3 无法识别 ApplicationWindow 的 member/property ApplicationWindow.toolbar 第二种情况？

Answer 1

好吧，这种二元性是因为有 2 个 ApplicationWindow，一个来自 import QtQuick.Controls 1.4，第二个来自 import QtQuick.Controls 2.3。新的没有 toolBar 所以你得到错误。

如果您仍想使用旧版本，可以按如下方式使用别名：

import QtQuick.Controls 1.4 as Old

Old.ApplicationWindow {    
    toolBar: ToolBar
    {
    }
}

或者您应该在新版本中使用 ApplicationWindow.header：

ApplicationWindow {
    header: TabBar {
        // ...
    }
}

不知道Qt为什么要把名字从toolBar改成header。对我来说这看起来不合逻辑。

由于导入错误，带工具栏的 ApplicationWindow 无法保存 SwipeView

ApplicationWindow with Toolbar cannot hold SwipeView because of import errors

qml

qtquickcontrols

qtquickcontrols2