Qt之生成png/jpg/bmp格式圖片
阿新 • • 發佈:2019-02-05
一、問題描述:有時候需要把Qt繪製的一些圖形儲存為png/jpg/bmp格式的圖片,下面就根據自己寫的一個簡單的測試程式來講解一下Qt中儲存圖片的方法。本文主要講解使用Qpainter和QImage組合使用儲存圖片的方法。
二、顯示效果:
1、介面顯示效果:
2、生成的圖片及圖片顯示效果:
三、核心程式碼示例:
#include "widget.h"
#include "ui_widget.h"
#include <QPen>
Widget::Widget(QWidget *parent) :
QWidget(parent),
ui(new Ui::Widget)
{
ui->setupUi(this );
this->setWindowTitle("測試繪製圖片並儲存為png/jpg/bmp格式");
drawPicture();
}
Widget::~Widget()
{
delete ui;
}
/// 重寫繪製事件,顯示在widgt上面
void Widget::paintEvent(QPaintEvent *event)
{
Q_UNUSED(event);
QPainter *painter = new QPainter(this);
painter->save();
QPen pen;
pen.setWidth(2 );
pen.setColor(Qt::red);
painter->setPen(pen);
painter->drawEllipse(QPoint(width()/2,height()/2),50,50);
painter->drawLine(QPointF(0,0),QPointF(width()/2,height()/2));
painter->drawRect(QRect(40,40,150,160));
painter->restore();
painter->end();
}
/// 繪製圖片中
void Widget::drawPicture()
{
QImage image(QSize(this ->width(),this->height()),QImage::Format_ARGB32);
image.fill("white");
QPainter *painter = new QPainter(&image);
painter->save();
QPen pen;
pen.setWidth(2);
pen.setColor(Qt::red);
painter->setPen(pen);
painter->drawEllipse(QPoint(width()/2,height()/2),50,50);
painter->drawLine(QPointF(0,0),QPointF(width()/2,height()/2));
painter->drawRect(QRect(40,40,150,160));
painter->restore();
painter->end();
m_image = image;
}
/// 儲存為圖片
void Widget::savePicture(const QString fileName, const char *format)
{
m_image.save(fileName,format);
}