Create custom QML for QT

Create a QML can be import by other QML

description

to avoid a QML file too height, and create re-usable module, I introduction 2 methods in here:

• QML built-in
• QML in rcc file

notice

there are some points and both of built-in and rcc file are almost the same:

• qmldir file
• the root of QML module, need use Item QML object, it will let QML editor parser correct

How to do

Built-in

• create a qml file (e.g. extend.qml) with content:

import QtQuick 2.0
import QtQuick.Controls 2.0

Item {
  Rectangle {
    anchors.fill: parent
    ...
  }
}

• create a qmldir file with content:

ExtendObj 1.0 extend.qml

• add qml file and qmldir file into QRC file with prefix (e.g. modules)

<RCC>
    <qresource prefix="/">
        <file>main.qml</file>
    </qresource>
    <qresource prefix="/modules">
        <file>extend.qml</file>
        <file>qmldir</file>
    </qresource>
</RCC>

• import the ExtendObj in main.qml (or other qml file):

import QtQuick 2.0
import QtQuick.Window 2.2
import "qrc:/modules"

Window {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")

    ExtendObj {
        anchors.fill: parent
        ...
    }
}

now, you can use the QML module that is built by yourself.

external RCC filo

we only adjust some procedure from built-in methods (still use extend.qml and qmldir)

• create a new qrc file (e.g. common.qrc)

<RCC>
    <qresource prefix="/modules">
        <file>extend.qml</file>
        <file>qmldir</file>
    </qresource>
</RCC>

• build rcc file by using QT utility “rcc”

rcc -binary common.qrc -o common.rcc

• load rcc while start program (load it in main.cpp), the point is runtime loading and working directory

#include <QResource>
...
...
QResource::registerResource("common.rcc")

and you can use the same method to call your modules in main.qml (or other QML files).

Deploy QT applicaton in Windows sytem

Deploy QT application for windows

description

QT has a utility can help you to prepare all of dependence dynamic libraries, it can let you deploy application more convenient.

pre-condition

1. assume QT source code in path <src_path>, and all of QML files are stored in <src_path>\qml
2. a built application file <application> and stored in <release> folder
3. QT utilities are stored in <qt_common_folder>/bin (e.g. c:\Qt\x.xx\mingw_xx\bin)

procedure

cd <release>
<qt_common_folder>\bin\windeployqt.exe --qml_dir <src_path>\qml <application>

this utility will copy the common libraries to the release folder