QT学习笔记之十 Ticker

无聊学习着......写一个Ticker，练习下事件触发=============================================================部分代码如下：ticker.h#ifndef TICKER_H#define TICKER_H#include namespace Ui{class Ticker;}

核动力蜗牛Killua

1410人浏览 · 2009-07-03 14:25:00

核动力蜗牛Killua · 2009-07-03 14:25:00 发布

无聊学习着......

写一个Ticker，练习下事件触发

=============================================================

部分代码如下：

ticker.h

#ifndef TICKER_H #define TICKER_H #include <QtGui/QWidget> namespace Ui { class Ticker; } class Ticker : public QWidget { Q_OBJECT public: Ticker(QWidget *parent = 0); ~Ticker(); void setText(const QString &newText); QString text() const ; QSize sizeHint() const; protected: void paintEvent(QPaintEvent *event); void timerEvent(QTimerEvent *evnet); void showEvent(QShowEvent *event); void hideEvent(QHideEvent *event); private: Ui::Ticker *ui; QString tickerText; int offset; //时间间隔 int timerID; //定时器ID }; #endif // TICKER_H

ticker.cpp

#include <QtGui> #include "ticker.h" #include "ui_ticker.h" Ticker::Ticker(QWidget *parent) : QWidget(parent), ui(new Ui::Ticker) { ui->setupUi(this); offset = 0; timerID = 0; } Ticker::~Ticker() { delete ui; } /** 设置文本 */ void Ticker::setText(const QString &newText) { tickerText = newText; update(); updateGeometry(); } /** 获取文本内容 */ QString Ticker::text() const { return tickerText; } /** 设置Widget大小 */ QSize Ticker::sizeHint() const { return fontMetrics().size(0,text()); //fontMetrics(): Returns the font metrics for the widget's current font } /** 绘制事件 */ void Ticker::paintEvent(QPaintEvent *) { QPainter painter(this); int textWidth = fontMetrics().width(text()); if (textWidth < 1) return ; int x = -offset; while (x < width()) { painter.drawText(x,0,textWidth,height(),Qt::AlignLeft | Qt::AlignVCenter,text()); //绘制文本 x += textWidth; } } /** 定时器事件 */ void Ticker::timerEvent(QTimerEvent *event) { if (event->timerId() == timerID) { ++offset; if(offset >= fontMetrics().width(text())) offset = 0; scroll(-1,0); //向左滚动一个像素 } else { QWidget::timerEvent(event); } } /** 显示事件 */ void Ticker::showEvent(QShowEvent *) { timerID = startTimer(30); //Starts a timer and returns a timer identifier, or returns zero if it could not start a timer. } /** 隐藏事件 */ void Ticker::hideEvent(QHideEvent *) { killTimer(timerID); timerID = 0; }

界面截图如下：