Qt（QLabel）实现滚动字幕

fontMetrics().width("a");//每个字符的宽度

#ifndef TEXTTICKER_H
#define TEXTTICKER_H


#include <QtWidgets/QLabel>


class TextTicker : public QLabel
{
	Q_OBJECT


public:
	TextTicker(QWidget *parent = 0);
	~TextTicker();


protected:
	void paintEvent(QPaintEvent *event);
	void updateIndex();


private:
	int m_charWidth;
	int m_curIndex;
	QString m_showText;
};


#endif // TEXTTICKER_H

#include "textticker.h"
#include <QPainter>
#include <QTimer>


TextTicker::TextTicker(QWidget *parent)
	: QLabel(parent)
{
	setMinimumWidth(200);
	setMinimumHeight(40);


	m_curIndex = 0;//当前角码
	m_showText = "This is a textTicker Text!";//显示的文字
	m_charWidth = fontMetrics().width("a");//每个字符的宽度


	QTimer *timer = new QTimer(this);
	connect(timer, &QTimer::timeout, this, &TextTicker::updateIndex);
	timer->start(100);
}


TextTicker::~TextTicker()
{


}


void TextTicker::paintEvent(QPaintEvent *event)
{
	__super::paintEvent(event);
	QPainter painter(this);
	painter.drawText(0, 30, m_showText.mid(m_curIndex));
	painter.drawText(width() - m_charWidth*m_curIndex, 30, m_showText.left(m_curIndex));
}


void TextTicker::updateIndex()
{
	update();
	m_curIndex++;
	if (m_curIndex*m_charWidth > width())
		m_curIndex = 0;
}

Qt（QLabel）实现滚动字幕

原文：http://blog.csdn.net/u011417605/article/details/51211853