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滚动字幕，也叫跑马，就是动态显示一行字符。前面实现是使用QTimer控制，直接在槽函数中截取字符串进行显示，只控制字符串在控件的一端显示，超出控件的部分并没有从控件的另一端循环显示出来。于是我重新实现了一种方法，或者说完善了前面的不足吧。
fontMetrics().width("a");//每个字符的宽度完整示例代码：#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;
}交流QQ：1245178753标签：
原文地址：http://blog.csdn.net/u011417605/article/details/51211853
