【翻译】利用Qt设计师窗体在运行时创建用户界面（Creating a user interface from a Qt Designer form at run-time）

时间：2024-01-20 11:27:15

利用Qt设计师窗体在运行时创建用户界面

【翻译】利用Qt设计师窗体在运行时创建用户界面（Creating a user interface from a Qt Designer form at run-time）

我们利用Calculator窗体例子中创建的窗体（Form）来展示当一个应用（application）已经生成后，是可以在其运行时产生与例子中相同的用户界面。

准备

Calculator窗体例子定好了一个无须修改，可直接使用的用户界面。在本例子中，我们使用一个资源文件来包含之前例子中的calculatorform.ui，它也可以存储在硬盘上。

为了在运行时生成窗体，我们需要在本例子中将QtUiTools 模块库链接进来，工程文件包含了所有需要的信息：

 HEADERS     = calculatorform.h

 RESOURCES   = calculatorbuilder.qrc

 SOURCES     = calculatorform.cpp \

               main.cpp

 QT += widgets uitools

正常声明其他的必要文件。

定义CalculatorForm类

CalculatorForm类定义了一个部件（widget）来包含该窗体的用户界面

class CalculatorForm : public QWidget

{

    Q_OBJECT

public:

    CalculatorForm(QWidget *parent = );

private slots:

    void on_inputSpinBox1_valueChanged(int value);

    void on_inputSpinBox2_valueChanged(int value);

private:

    QSpinBox *ui_inputSpinBox1;

    QSpinBox *ui_inputSpinBox2;

    QLabel *ui_outputWidget;

};

注意到，我们并不需要包含一个头文件来解释该用户界面。我们只是使用了uic要求的auto-connection naming convention定义了两个public槽（slot），并声明了两个私有变量来访问我们构造的窗体中的部件。

实现（Implementation）CalculatorForm类

我们需要使用libQtUiTools库提供的QUiLoader类，因此我们包含该库的头文件

#include <QtUiTools>

构造函数使用窗体载入对象和QFile对象通过资源文件来构造我们要实现的用户界面

CalculatorForm::CalculatorForm(QWidget *parent)

    : QWidget(parent)

{

    QUiLoader loader;

    QFile file(":/forms/calculatorform.ui");

    file.open(QFile::ReadOnly);

    QWidget *formWidget = loader.load(&file, this);

    file.close();

通过在该例子的资源中包含用户界面，确保其在该例子运行时显示出来。loader.load()函数读取文件中包含的用户界面信息，并构造一个窗体作为该CalculatorForm对象的子部件。

我们对生成的用户界面中的两个spin box和一个标签（label）感兴趣，我们重新得到三个指向它们的指针。qFindChild()模板函数使得我们可以按名字依次遍历部件来找到对应的子部件。

    ui_inputSpinBox1 = findChild<QSpinBox*>("inputSpinBox1");

    ui_inputSpinBox2 = findChild<QSpinBox*>("inputSpinBox2");

    ui_outputWidget = findChild<QLabel*>("outputWidget");

窗体载入器（form loader）创建的部件需要与CalculatorForm对象中专有命名（specially-named）的槽连接起来，我们使用Qt的meta-object system来实现

    QMetaObject::connectSlotsByName(this);

将窗体部件添加到一个布局（layout）中，并设置标题。

    QVBoxLayout *layout = new QVBoxLayout;

    layout->addWidget(formWidget);

    setLayout(layout);

    setWindowTitle(tr("Calculator Builder"));

}

两个修改窗体部件的槽函数与Calculator Form例子中的类似，唯一的区别在于我们使用指针来读写这些部件

void CalculatorForm::on_inputSpinBox1_valueChanged(int value)

{

    ui_outputWidget->setText(QString::number(value + ui_inputSpinBox2->value()));

}

void CalculatorForm::on_inputSpinBox2_valueChanged(int value)

{

    ui_outputWidget->setText(QString::number(value + ui_inputSpinBox1->value()));

}

文件：

calculatorbuilder/calculatorform.cpp

/****************************************************************************

**

** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).

** Contact: http://www.qt-project.org/legal

**

** This file is part of the examples of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:BSD$

** You may use this file under the terms of the BSD license as follows:

**

** "Redistribution and use in source and binary forms, with or without

** modification, are permitted provided that the following conditions are

** met:

**   * Redistributions of source code must retain the above copyright

**     notice, this list of conditions and the following disclaimer.

**   * Redistributions in binary form must reproduce the above copyright

**     notice, this list of conditions and the following disclaimer in

**     the documentation and/or other materials provided with the

**     distribution.

**   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names

**     of its contributors may be used to endorse or promote products derived

**     from this software without specific prior written permission.

**

**

** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."

**

** $QT_END_LICENSE$

**

****************************************************************************/

#include <QtUiTools>

#include <QSpinBox>

#include <QLabel>

#include <QVBoxLayout>

#include <QFile>

#include "calculatorform.h"

CalculatorForm::CalculatorForm(QWidget *parent)

    : QWidget(parent)

{

    QUiLoader loader;

    QFile file(":/forms/calculatorform.ui");

    file.open(QFile::ReadOnly);

    QWidget *formWidget = loader.load(&file, this);

    file.close();

    ui_inputSpinBox1 = findChild<QSpinBox*>("inputSpinBox1");

    ui_inputSpinBox2 = findChild<QSpinBox*>("inputSpinBox2");

    ui_outputWidget = findChild<QLabel*>("outputWidget");

    QMetaObject::connectSlotsByName(this);

    QVBoxLayout *layout = new QVBoxLayout;

    layout->addWidget(formWidget);

    setLayout(layout);

    setWindowTitle(tr("Calculator Builder"));

}

void CalculatorForm::on_inputSpinBox1_valueChanged(int value)

{

    ui_outputWidget->setText(QString::number(value + ui_inputSpinBox2->value()));

}

void CalculatorForm::on_inputSpinBox2_valueChanged(int value)

{

    ui_outputWidget->setText(QString::number(value + ui_inputSpinBox1->value()));

}

calculatorbuilder/calculatorform.h

/****************************************************************************

**

** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).

** Contact: http://www.qt-project.org/legal

**

** This file is part of the examples of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:BSD$

** You may use this file under the terms of the BSD license as follows:

**

** "Redistribution and use in source and binary forms, with or without

** modification, are permitted provided that the following conditions are

** met:

**   * Redistributions of source code must retain the above copyright

**     notice, this list of conditions and the following disclaimer.

**   * Redistributions in binary form must reproduce the above copyright

**     notice, this list of conditions and the following disclaimer in

**     the documentation and/or other materials provided with the

**     distribution.

**   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names

**     of its contributors may be used to endorse or promote products derived

**     from this software without specific prior written permission.

**

**

** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."

**

** $QT_END_LICENSE$

**

****************************************************************************/

#ifndef CALCULATORFORM_H

#define CALCULATORFORM_H

#include <QWidget>

class QLabel;

class QSpinBox;

class CalculatorForm : public QWidget

{

    Q_OBJECT

public:

    CalculatorForm(QWidget *parent = );

private slots:

    void on_inputSpinBox1_valueChanged(int value);

    void on_inputSpinBox2_valueChanged(int value);

private:

    QSpinBox *ui_inputSpinBox1;

    QSpinBox *ui_inputSpinBox2;

    QLabel *ui_outputWidget;

};

#endif

calculatorbuilder/calculatorform.ui

<ui version="4.0" >

 <author></author>

 <comment></comment>

 <exportmacro></exportmacro>

 <class>CalculatorForm</class>

 <widget class="QWidget" name="CalculatorForm" >

  <property name="objectName" >

   <string notr="true" >CalculatorForm</string>

  </property>

  <property name="geometry" >

   <rect>

    <x></x>

    <y></y>

    <width></width>

    <height></height>

   </rect>

  </property>

  <property name="sizePolicy" >

   <sizepolicy>

    <hsizetype></hsizetype>

    <vsizetype></vsizetype>

    <horstretch></horstretch>

    <verstretch></verstretch>

   </sizepolicy>

  </property>

  <property name="windowTitle" >

   <string>Calculator Builder</string>

  </property>

  <layout class="QGridLayout" >

   <property name="objectName" >

    <string notr="true" />

   </property>

   <property name="margin" >

    <number></number>

   </property>

   <property name="spacing" >

    <number></number>

   </property>

   <item row="" column="" >

    <layout class="QHBoxLayout" >

     <property name="objectName" >

      <string notr="true" />

     </property>

     <property name="margin" >

      <number></number>

     </property>

     <property name="spacing" >

      <number></number>

     </property>

     <item>

      <layout class="QVBoxLayout" >

       <property name="objectName" >

        <string notr="true" />

       </property>

       <property name="margin" >

        <number></number>

       </property>

       <property name="spacing" >

        <number></number>

       </property>

       <item>

        <widget class="QLabel" name="label" >

         <property name="objectName" >

          <string notr="true" >label</string>

         </property>

         <property name="geometry" >

          <rect>

           <x></x>

           <y></y>

           <width></width>

           <height></height>

          </rect>

         </property>

         <property name="text" >

          <string>Input </string>

         </property>

        </widget>

       </item>

       <item>

        <widget class="QSpinBox" name="inputSpinBox1" >

         <property name="objectName" >

          <string notr="true" >inputSpinBox1</string>

         </property>

         <property name="geometry" >

          <rect>

           <x></x>

           <y></y>

           <width></width>

           <height></height>

          </rect>

         </property>

         <property name="mouseTracking" >

          <bool>true</bool>

         </property>

        </widget>

       </item>

      </layout>

     </item>

     <item>

      <widget class="QLabel" name="label_3" >

       <property name="objectName" >

        <string notr="true" >label_3</string>

       </property>

       <property name="geometry" >

        <rect>

         <x></x>

         <y></y>

         <width></width>

         <height></height>

        </rect>

       </property>

       <property name="text" >

        <string>+</string>

       </property>

       <property name="alignment" >

        <set>Qt::AlignCenter</set>

       </property>

      </widget>

     </item>

     <item>

      <layout class="QVBoxLayout" >

       <property name="objectName" >

        <string notr="true" />

       </property>

       <property name="margin" >

        <number></number>

       </property>

       <property name="spacing" >

        <number></number>

       </property>

       <item>

        <widget class="QLabel" name="label_2" >

         <property name="objectName" >

          <string notr="true" >label_2</string>

         </property>

         <property name="geometry" >

          <rect>

           <x></x>

           <y></y>

           <width></width>

           <height></height>

          </rect>

         </property>

         <property name="text" >

          <string>Input </string>

         </property>

        </widget>

       </item>

       <item>

        <widget class="QSpinBox" name="inputSpinBox2" >

         <property name="objectName" >

          <string notr="true" >inputSpinBox2</string>

         </property>

         <property name="geometry" >

          <rect>

           <x></x>

           <y></y>

           <width></width>

           <height></height>

          </rect>

         </property>

         <property name="mouseTracking" >

          <bool>true</bool>

         </property>

        </widget>

       </item>

      </layout>

     </item>

     <item>

      <widget class="QLabel" name="label_3_2" >

       <property name="objectName" >

        <string notr="true" >label_3_2</string>

       </property>

       <property name="geometry" >

        <rect>

         <x></x>

         <y></y>

         <width></width>

         <height></height>

        </rect>

       </property>

       <property name="text" >

        <string>=</string>

       </property>

       <property name="alignment" >

        <set>Qt::AlignCenter</set>

       </property>

      </widget>

     </item>

     <item>

      <layout class="QVBoxLayout" >

       <property name="objectName" >

        <string notr="true" />

       </property>

       <property name="margin" >

        <number></number>

       </property>

       <property name="spacing" >

        <number></number>

       </property>

       <item>

        <widget class="QLabel" name="label_2_2_2" >

         <property name="objectName" >

          <string notr="true" >label_2_2_2</string>

         </property>

         <property name="geometry" >

          <rect>

           <x></x>

           <y></y>

           <width></width>

           <height></height>

          </rect>

         </property>

         <property name="text" >

          <string>Output</string>

         </property>

        </widget>

       </item>

       <item>

        <widget class="QLabel" name="outputWidget" >

         <property name="objectName" >

          <string notr="true" >outputWidget</string>

         </property>

         <property name="geometry" >

          <rect>

           <x></x>

           <y></y>

           <width></width>

           <height></height>

          </rect>

         </property>

         <property name="frameShape" >

          <enum>QFrame::Box</enum>

         </property>

         <property name="frameShadow" >

          <enum>QFrame::Sunken</enum>

         </property>

         <property name="text" >

          <string></string>

         </property>

         <property name="alignment" >

          <set>Qt::AlignAbsolute|Qt::AlignBottom|Qt::AlignCenter|Qt::AlignHCenter|Qt::AlignHorizontal_Mask|Qt::AlignJustify|Qt::AlignLeading|Qt::AlignLeft|Qt::AlignRight|Qt::AlignTop|Qt::AlignTrailing|Qt::AlignVCenter|Qt::AlignVertical_Mask</set>

         </property>

        </widget>

       </item>

      </layout>

     </item>

    </layout>

   </item>

   <item row="" column="" >

    <spacer>

     <property name="objectName" >

      <string notr="true" >verticalSpacer</string>

     </property>

     <property name="geometry" >

      <rect>

       <x></x>

       <y></y>

       <width></width>

       <height></height>

      </rect>

     </property>

     <property name="orientation" >

      <enum>Qt::Vertical</enum>

     </property>

     <property name="sizeHint" >

      <size>

       <width></width>

       <height></height>

      </size>

     </property>

    </spacer>

   </item>

   <item row="" column="" >

    <spacer>

     <property name="objectName" >

      <string notr="true" >horizontalSpacer</string>

     </property>

     <property name="geometry" >

      <rect>

       <x></x>

       <y></y>

       <width></width>

       <height></height>

      </rect>

     </property>

     <property name="orientation" >

      <enum>Qt::Horizontal</enum>

     </property>

     <property name="sizeHint" >

      <size>

       <width></width>

       <height></height>

      </size>

     </property>

    </spacer>

   </item>

  </layout>

 </widget>

 <pixmapfunction></pixmapfunction>

 <resources/>

 <connections/>

</ui>

calculatorbuilder/main.cpp

/****************************************************************************

**

** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).

** Contact: http://www.qt-project.org/legal

**

** This file is part of the examples of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:BSD$

** You may use this file under the terms of the BSD license as follows:

**

** "Redistribution and use in source and binary forms, with or without

** modification, are permitted provided that the following conditions are

** met:

**   * Redistributions of source code must retain the above copyright

**     notice, this list of conditions and the following disclaimer.

**   * Redistributions in binary form must reproduce the above copyright

**     notice, this list of conditions and the following disclaimer in

**     the documentation and/or other materials provided with the

**     distribution.

**   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names

**     of its contributors may be used to endorse or promote products derived

**     from this software without specific prior written permission.

**

**

** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."

**

** $QT_END_LICENSE$

**

****************************************************************************/

#include <QApplication>

#include "calculatorform.h"

int main(int argc, char *argv[])

{

    Q_INIT_RESOURCE(calculatorbuilder);

    QApplication app(argc, argv);

    CalculatorForm calculator;

    calculator.show();

    return app.exec();

}

calculatorbuilder/calculatorbuilder.pro

HEADERS     = calculatorform.h

RESOURCES   = calculatorbuilder.qrc

SOURCES     = calculatorform.cpp \

              main.cpp

QT += widgets uitools

target.path = $$[QT_INSTALL_EXAMPLES]/designer/calculatorbuilder

INSTALLS += target

calculatorbuilder/calculatorbuilder.qrc

<!DOCTYPE RCC><RCC version="1.0">

<qresource prefix="/forms">

   <file>calculatorform.ui</file>

</qresource>

</RCC>

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