官方的这个例子比较有意思，在此记录下，方便以后查阅。
Hello Speak Example
这个例子主要是使用QTextToSpeech类将用户自定义输入的文本转换为口语，包括高低音、声音大小、读速。并且能够选择语言和声音。
包含的文件如下：
本篇博文，主要记录下如何使用QTextToSpeech将文字转换为口语。
QTextToSpeech Class
这里先来看下这个类，使用他需要在pro文件添加texttospeech。关于这个类的描述如下：
QTextToSpeech类提供了text-to-speech的引擎，这个引擎使用及其方便。
使用say()，就能将文字转换为口语，并且他能通过setLocale()指定语言，使用setVoice()选择声音。这里有点要注意这些语言和声音依赖于本地机器是否支持。
下面是关于QTextToSpeech::State
| constant | value | description |
| QTextToSpeech::Ready | 0 | 文本输入完后，准备将输入的文本转换为口语。 |
| QTextToSpeech::Speaking | 1 | 文本正在转换为口语。 |
| QTextToSpeech::Paused | 2 | 暂停，调用resume()进行恢复。 |
| QTextToSpeech::BackendError | 3 | 转换口语后端发生错误时 |
解析
下面主要是来看下，这个例子，是如何将文本转换为口语的。
关键.h文件：
mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QtWidgets/qmainwindow.h>
#include "ui_mainwindow.h"
#include <QTextToSpeech>
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow(QWidget *parent = 0);
public slots:
void speak();
void stop();
void setRate(int);
void setPitch(int);
void setVolume(int volume);
void stateChanged(QTextToSpeech::State state);
void engineSelected(int index);
void languageSelected(int language);
void voiceSelected(int index);
void localeChanged(const QLocale &locale);
private:
Ui::MainWindow ui;
QTextToSpeech *m_speech;
QVector<QVoice> m_voices;
};
#endif关键.cpp文件
mainwindow.cpp
#include "mainwindow.h"
#include <QLoggingCategory>
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent),
m_speech(0)
{
ui.setupUi(this);
//QLoggingCategory::setFilterRules(QStringLiteral("qt.speech.tts=true \n qt.speech.tts.*=true"));
// Populate engine selection list
ui.engine->addItem("Default", QString("default"));
foreach (QString engine, QTextToSpeech::availableEngines())
ui.engine->addItem(engine, engine);
ui.engine->setCurrentIndex(0);
engineSelected(0);
connect(ui.speakButton, &QPushButton::clicked, this, &MainWindow::speak);
connect(ui.pitch, &QSlider::valueChanged, this, &MainWindow::setPitch);
connect(ui.rate, &QSlider::valueChanged, this, &MainWindow::setRate);
connect(ui.volume, &QSlider::valueChanged, this, &MainWindow::setVolume);
connect(ui.engine, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this, &MainWindow::engineSelected);
}
void MainWindow::speak()
{
m_speech->say(ui.plainTextEdit->toPlainText());
}
void MainWindow::stop()
{
m_speech->stop();
}
void MainWindow::setRate(int rate)
{
m_speech->setRate(rate / 10.0);
}
void MainWindow::setPitch(int pitch)
{
m_speech->setPitch(pitch / 10.0);
}
void MainWindow::setVolume(int volume)
{
m_speech->setVolume(volume / 100.0);
}
void MainWindow::stateChanged(QTextToSpeech::State state)
{
if (state == QTextToSpeech::Speaking) {
ui.statusbar->showMessage("Speech started...");
} else if (state == QTextToSpeech::Ready)
ui.statusbar->showMessage("Speech stopped...", 2000);
else if (state == QTextToSpeech::Paused)
ui.statusbar->showMessage("Speech paused...");
else
ui.statusbar->showMessage("Speech error!");
ui.pauseButton->setEnabled(state == QTextToSpeech::Speaking);
ui.resumeButton->setEnabled(state == QTextToSpeech::Paused);
ui.stopButton->setEnabled(state == QTextToSpeech::Speaking || state == QTextToSpeech::Paused);
}
void MainWindow::engineSelected(int index)
{
QString engineName = ui.engine->itemData(index).toString();
delete m_speech;
if (engineName == "default")
m_speech = new QTextToSpeech(this);
else
m_speech = new QTextToSpeech(engineName, this);
disconnect(ui.language, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this, &MainWindow::languageSelected);
ui.language->clear();
// Populate the languages combobox before connecting its signal.
QVector<QLocale> locales = m_speech->availableLocales();
QLocale current = m_speech->locale();
foreach (const QLocale &locale, locales) {
QString name(QString("%1 (%2)")
.arg(QLocale::languageToString(locale.language()))
.arg(QLocale::countryToString(locale.country())));
QVariant localeVariant(locale);
ui.language->addItem(name, localeVariant);
if (locale.name() == current.name())
current = locale;
}
setRate(ui.rate->value());
setPitch(ui.pitch->value());
setVolume(ui.volume->value());
connect(ui.stopButton, &QPushButton::clicked, m_speech, &QTextToSpeech::stop);
connect(ui.pauseButton, &QPushButton::clicked, m_speech, &QTextToSpeech::pause);
connect(ui.resumeButton, &QPushButton::clicked, m_speech, &QTextToSpeech::resume);
connect(m_speech, &QTextToSpeech::stateChanged, this, &MainWindow::stateChanged);
connect(m_speech, &QTextToSpeech::localeChanged, this, &MainWindow::localeChanged);
connect(ui.language, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this, &MainWindow::languageSelected);
localeChanged(current);
}
void MainWindow::languageSelected(int language)
{
QLocale locale = ui.language->itemData(language).toLocale();
m_speech->setLocale(locale);
}
void MainWindow::voiceSelected(int index)
{
m_speech->setVoice(m_voices.at(index));
}
void MainWindow::localeChanged(const QLocale &locale)
{
QVariant localeVariant(locale);
ui.language->setCurrentIndex(ui.language->findData(localeVariant));
disconnect(ui.voice, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this, &MainWindow::voiceSelected);
ui.voice->clear();
m_voices = m_speech->availableVoices();
QVoice currentVoice = m_speech->voice();
foreach (const QVoice &voice, m_voices) {
ui.voice->addItem(QString("%1 - %2 - %3").arg(voice.name())
.arg(QVoice::genderName(voice.gender()))
.arg(QVoice::ageName(voice.age())));
if (voice.name() == currentVoice.name())
ui.voice->setCurrentIndex(ui.voice->count() - 1);
}
connect(ui.voice, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this, &MainWindow::voiceSelected);
}下面来跟一下这个m_speech是如何用的。
在.cpp中可以看到：
将engineName传入了QTextToSpeech的构造函数，而engineName的值来自于
QTextToSpeech::availableEngines()。
这里来看下，他是如何选择语言和音频的，
connect(ui.language, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this, &MainWindow::languageSelected);
connect(ui.voice, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this, &MainWindow::voiceSelected);对应的槽函数分别为：
void MainWindow::languageSelected(int language)
{
QLocale locale = ui.language->itemData(language).toLocale();
m_speech->setLocale(locale);
}
void MainWindow::voiceSelected(int index)
{
m_speech->setVoice(m_voices.at(index));
}从中可以看到，这里封装好的，应用层调用的确是简单太多。
下面看下，他是如何播放、暂停、续播：
connect(ui.stopButton, &QPushButton::clicked, m_speech, &QTextToSpeech::stop);
connect(ui.pauseButton, &QPushButton::clicked, m_speech, &QTextToSpeech::pause);
connect(ui.resumeButton, &QPushButton::clicked, m_speech, &QTextToSpeech::resume);关于设置音调，读速的相关代码如下：
void MainWindow::setRate(int rate)
{
m_speech->setRate(rate / 10.0);
}
void MainWindow::setPitch(int pitch)
{
m_speech->setPitch(pitch / 10.0);
}
void MainWindow::setVolume(int volume)
{
m_speech->setVolume(volume / 100.0);
}
