LINUX下QT写的图像显示DEMO

/**************************************************************************** ** ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). ** All rights reserved. ** Contact: Nokia Corporation (qt-info@nokia.com) ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** You may use this file under the terms of the BSD license as follows: ** ** "Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions are ** met: ** * Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** * Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in ** the documentation and/or other materials provided with the ** distribution. ** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor ** the names of its contributors may be used to endorse or promote ** products derived from this software without specific prior written ** permission. ** ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ** $QT_END_LICENSE$ ** ****************************************************************************/ #include <QtGui> #include "helper.h" //! [0] Helper::Helper() { QLinearGradient gradient(QPointF(50, -20), QPointF(80, 20)); gradient.setColorAt(0.0, Qt::white); gradient.setColorAt(1.0, QColor(0xa6, 0xce, 0x39)); background = QBrush(QColor(64, 32, 64)); img.load("test.jpg"); } //! [0] //! [1] void Helper::paint(QPainter *painter, QPaintEvent *event, int elapsed) { painter->fillRect(event->rect(), background); //! [1] //! [2] unsigned char *rgbdata = img.bits(); int height = img.height(); int width = img.width(); QImage *image = new QImage(rgbdata, width, height, QImage::Format_RGB32); QRect rect = event->rect(); QRect source(0.0, 0.0, width, height); //建立源矩形，用来划定来自外部的源图像文件中需要显示的区域 /* printf("rect width is %d, rect height is %d\n", rect.width(), rect.height()); printf("image width is %d, image height is %d\n", width, height); printf("channel is %d\n", img.depth());*/ painter->drawImage(rect, *image, source); delete image; } //! [3]