当我尝试在qt中创建相机应用程序时出现以下错误：
错误：没有匹配函数来调用'QWidget :: QWidget（const QWidget *＆amp;，const char *＆amp;）'
答案 0 :(得分：0)
我认为你误用了QWidget。 您应该阅读http://qt-project.org/doc/qt-5.0/qtwidgets/qwidget.html#QWidget
此外，如果你发送你的代码，它会有所帮助。
no matching function for call to ‘QSplashScreen::finish()’表示没有finish（）方法。
答案 1 :(得分：0)
** .cpp ** #include <stdlib.h>
#include <QApplication>
#include <QWidget>
#include <QTimer>
#include <QPainter>
#include <QMatrix>
#include <QSplashScreen>
#include <QFileDialog>
#include <QPushButton>
#include <QImage>
#include <QPixmap>
#include <QDateTime>
//#include <QAudioOutput>
//#include <QtMultimedia>
#include "webcam.h"
#include "SplashScreen.h"
#include "mydialog.h"
#define VAL 0
#define VAL1 1
static unsigned char huffman_table[] = {
0xFF,0xC4,0x01,0xA2,0x00,0x00,0x01,0x05,0x01,0x01,0x01,0x01,
0x01,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x02,
0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x01,0x00,0x03,
0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x00,0x00,0x00,
0x00,0x00,0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,
0x0A,0x0B,0x10,0x00,0x02,0x01,0x03,0x03,0x02,0x04,0x03,0x05,
0x05,0x04,0x04,0x00,0x00,0x01,0x7D,0x01,0x02,0x03,0x00,0x04,
0x11,0x05,0x12,0x21,0x31,0x41,0x06,0x13,0x51,0x61,0x07,0x22,
0x71,0x14,0x32,0x81,0x91,0xA1,0x08,0x23,0x42,0xB1,0xC1,0x15,
0x52,0xD1,0xF0,0x24,0x33,0x62,0x72,0x82,0x09,0x0A,0x16,0x17,
0x18,0x19,0x1A,0x25,0x26,0x27,0x28,0x29,0x2A,0x34,0x35,0x36,
0x37,0x38,0x39,0x3A,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4A,
0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0x63,0x64,0x65,0x66,
0x67,0x68,0x69,0x6A,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,
0x83,0x84,0x85,0x86,0x87,0x88,0x89,0x8A,0x92,0x93,0x94,0x95,
0x96,0x97,0x98,0x99,0x9A,0xA2,0xA3,0xA4,0xA5,0xA6,0xA7,0xA8,
0xA9,0xAA,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0xC2,
0xC3,0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xD2,0xD3,0xD4,0xD5,
0xD6,0xD7,0xD8,0xD9,0xDA,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,
0xE8,0xE9,0xEA,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,0xF9,
0xFA,0x11,0x00,0x02,0x01,0x02,0x04,0x04,0x03,0x04,0x07,0x05,
0x04,0x04,0x00,0x01,0x02,0x77,0x00,0x01,0x02,0x03,0x11,0x04,
0x05,0x21,0x31,0x06,0x12,0x41,0x51,0x07,0x61,0x71,0x13,0x22,
0x32,0x81,0x08,0x14,0x42,0x91,0xA1,0xB1,0xC1,0x09,0x23,0x33,
0x52,0xF0,0x15,0x62,0x72,0xD1,0x0A,0x16,0x24,0x34,0xE1,0x25,
0xF1,0x17,0x18,0x19,0x1A,0x26,0x27,0x28,0x29,0x2A,0x35,0x36,
0x37,0x38,0x39,0x3A,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4A,
0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0x63,0x64,0x65,0x66,
0x67,0x68,0x69,0x6A,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,
0x82,0x83,0x84,0x85,0x86,0x87,0x88,0x89,0x8A,0x92,0x93,0x94,
0x95,0x96,0x97,0x98,0x99,0x9A,0xA2,0xA3,0xA4,0xA5,0xA6,0xA7,
0xA8,0xA9,0xAA,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,
0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xD2,0xD3,0xD4,
0xD5,0xD6,0xD7,0xD8,0xD9,0xDA,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,
0xE8,0xE9,0xEA,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,0xF9,0xFA};
struct v4l2_buffer buf;
unsigned int i,size,buf_size;
char filename[] = "quickcam-0000.jpg";
int dev, ret;
FILE *file;
void *mem;
unsigned char data[65000];
WebCam::WebCam( QWidget *parent, Qt::WindowFlags f)
: QWidget( parent, f )
{
setWindowTitle("Project : Qt/E USB Camera Image capture");
resize( QSize(320, 240).expandedTo(minimumSizeHint()) );
//ClearState( State_Polished );
video_open("/dev/video1");
QPixmap pixmap("logo.png");
// QSplashScreen* splash = new SplashScreen(pixmap);
QSplashScreen splash(pixmap);
splash.showMessage("Initialize...", 0,"Red");
qApp->processEvents();
sleep(3);
splash.finish(QWidget *Pixmap);
splash.deleteLater();
video_set_format();
video_reqbufs();
map_the_buffers();
Queue_the_buffers();
video_enable(dev,1);
start_streaming();
changeBKImage();
pmPaint = new QPixmap(320, 240);
capt = new QTimer( this );
capt->start(1);
connect( capt, SIGNAL(timeout()), SLOT(slotTimeout()) );
}
WebCam::~WebCam()
{
qWarning("USB-WebCamera exit!! \n");
capt->stop();
video_enable(dev,0);
munmap(mem,buf.length);
close(dev);
}
void WebCam::start_streaming()
{
memset(&buf, 0, sizeof buf);
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
ret = ioctl(dev, VIDIOC_DQBUF, &buf);
if (ret < 0)
{
printf("Unable to dequeue buffer (%d).\n", errno);
close(dev);
}
// Save the image.
sprintf(filename, "/root/quickcam-%03u.jpg", VAL1);
file = fopen(filename, "wb");
if (file != NULL)
{
unsigned char *input;
int input_size;
unsigned char *output;
// int output_data;
input = (unsigned char*)mem;
input_size=buf.bytesused;
int has_dht = 0;
output = data;
unsigned char hdr[4];
int o_count=0;
int r_count=0;
int size;
output[o_count++] = 0xFF;
output[o_count++] = 0xD8;
r_count += 2;
while(!has_dht)
{
memcpy(hdr, input+r_count, 4);
r_count += 4;
if(hdr[1]==0xC4) has_dht = 1;
else if(hdr[1]==0xDA) break;
// skip to the next marker
size = (hdr[2]<<8) + hdr[3];
memcpy(output+o_count, hdr, 4);
o_count += 4;
memcpy(output+o_count, input+r_count, size-2);
r_count += (size-2);
o_count += (size-2);
}
if(!has_dht)
{
memcpy(output+o_count, huffman_table, sizeof(huffman_table));
o_count += sizeof(huffman_table);
memcpy(output+o_count, hdr, 4);
o_count += 4;
}
// Process the remaining data in one go
memcpy(output+o_count, input+r_count, input_size-r_count);
o_count += (input_size-r_count);
r_count += (input_size-r_count);
input=NULL;
output=NULL;
fwrite(data,o_count,1,file);
fclose(file);
}
// Requeue the buffer.
ret = ioctl(dev, VIDIOC_QBUF, &buf);
if (ret < 0)
{
printf("Unable to requeue buffer (%d).\n", errno);
close(dev);
}
fflush(stdout);
}
void WebCam::Queue_the_buffers()
{
memset(&buf, 0, sizeof buf);
buf.index = VAL;
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
ret = ioctl(dev, VIDIOC_QBUF, &buf);
if (ret < 0)
{
printf("Unable to queue buffer (%d).\n", errno);
close(dev);
}
}
void WebCam::map_the_buffers()
{
memset(&buf, 0, sizeof buf);
buf.index = VAL;
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
ret = ioctl(dev, VIDIOC_QUERYBUF, &buf);
if (ret < 0)
{
printf("Unable to query buffer %u (%d).\n", VAL, errno);
close(dev);
}
printf("length: %u offset: %u\n", buf.length, buf.m.offset);
mem = mmap(0, buf.length, PROT_READ, MAP_SHARED, dev, buf.m.offset);
if (mem == MAP_FAILED)
{
printf("Unable to map buffer %u (%d)\n", VAL, errno);
close(dev);
}
printf("Buffer %u mapped at address %p\n", VAL, mem);
}
int WebCam::video_set_format()
{
struct v4l2_format fmt;
memset(&fmt, 0, sizeof fmt);
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
fmt.fmt.pix.width = 320;
fmt.fmt.pix.height = 240;
fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_MJPEG;
fmt.fmt.pix.field = V4L2_FIELD_ANY;
ret = ioctl(dev, VIDIOC_S_FMT, &fmt);
if (ret < 0) {
printf("Unable to set format: %d.\n", errno);
return ret;
}
printf("Video format set: width: %u height: %u buffer size: %u\n",
fmt.fmt.pix.width, fmt.fmt.pix.height, fmt.fmt.pix.sizeimage);
return 0;
}
int WebCam::video_reqbufs()
{
struct v4l2_requestbuffers rb;
memset(&rb, 0, sizeof rb);
rb.count = 16;
rb.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
rb.memory = V4L2_MEMORY_MMAP;
ret = ioctl(dev, VIDIOC_REQBUFS, &rb);
if (ret < 0)
{
printf("Unable to allocate buffers: %d.\n", errno);
return ret;
}
printf("%u buffers allocated.\n", rb.count);
return 0;
}
int WebCam::video_enable(int dev, int enable)
{
int type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
ret = ioctl(dev, enable ? VIDIOC_STREAMON : VIDIOC_STREAMOFF, &type);
if (ret < 0) {
printf("Unable to %s capture: %d.\n", enable ? "start" : "stop", errno);
return ret;
}
return 0;
}
int WebCam::video_open(const char *devname)
{
struct v4l2_capability cap;
dev = open(devname, O_RDWR);
if (dev < 0) {
printf("Error opening device %s: %d.\n", devname, errno);
exit(1);
}
memset(&cap, 0, sizeof cap);
ret = ioctl(dev, VIDIOC_QUERYCAP, &cap);
if (ret < 0) {
printf("Error opening device %s: unable to query device.\n",devname);
close(dev);
return ret;
}
if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {
printf("Error opening device %s: video capture not supported.\n",
devname);
close(dev);
return -EINVAL;
}
printf("Device %s opened: %s.\n", devname, cap.card);
return dev;
}
void WebCam::slotTimeout()
{
start_streaming();
changepmBKImage();
repaint(false);
}
void WebCam::paintEvent( QPaintEvent * )
{
QPainter painter(this);
drawImage();
painter.drawPixmap(0, 0, *pmPaint);
}
void WebCam::changepmBKImage()
{
QString strFilename;
strFilename.sprintf("/root/quickcam-%03d.jpg", VAL1);
if (!pmBk.load(strFilename)) {
qDebug("QPixmap load error\n");
}
}
void WebCam::drawImage()
{
QMatrix matrix;
QPainter painter;
QString strTime;
matrix.scale(-1.0,1.0);
pmBk=pmBk.xForm(matrix);
pmPaint->resize(width(), height());
painter.begin(pmPaint, this);
painter.drawPixmap(QPoint(0, 0),pixmapBk);
painter.end();
}
**.h file**
#ifndef WEBCAM_H
#define WEBCAM_H
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/select.h>
#include <QFileDialog>
#include <QPushButton>
#include <QPainter>
#include <QImage>
#include <QPixmap>
#include <QWidget>
#include <QDateTime>
#include <linux/videodev.h>
#include <linux/videodev2.h>
class WebCam : public QWidget
{
Q_OBJECT
public:
WebCam( QWidget* parent=0,Qt::WindowFlags f=0 );
// WebCam:: const char* name
~WebCam();
QPushButton* Exit;
QTimer *capt;
int video_open(const char *devname);
int video_set_format(void);
int video_reqbufs(void);
int video_enable(int dev, int enable);
int fixup_jpeg1(unsigned char *input, int input_size, unsigned char *output);
void map_the_buffers();
void Queue_the_buffers();
void start_streaming();
int i,n;
protected:
void paintEvent( QPaintEvent *);
private slots:
void slotTimeout();
private:
void drawImage();
void changeBKImage();
QTime time;
QPixmap *pixmapBk;
QPixmap *pmPaint;
QImage CMOSImage;
QFileDialog *fd;
};
#endif
答案 2 :(得分：0)
**errors**
/home/stesalit/Desktop/cam/webcam.cpp:90: error: no matching function for call to ‘QSplashScreen::finish()’
most repeating error
/home/stesalit/Desktop/cam/webcam.cpp:115: error: no matching function for call to ‘WebCam::close(int&)’
/home/stesalit/Desktop/cam/webcam.cpp:139: error: conflicting declaration ‘int output’
/home/stesalit/Desktop/cam/webcam.cpp:138: error: ‘output’ has a previous declaration as ‘unsigned char* output’
/home/stesalit/Desktop/cam/../../qtsdk-2009.05/qt/include/QtGui/qwidget.h:783: error: ‘QWidgetData* QWidget::data’ is private
/home/stesalit/Desktop/cam/webcam.cpp:141: error: within this context
/home/stesalit/Desktop/cam/webcam.cpp:141: error: cannot convert ‘QWidgetData*’ to ‘unsigned char*’ in assignment
/home/stesalit/Desktop/cam/../../qtsdk-2009.05/qt/include/QtGui/qwidget.h:783: error: ‘QWidgetData* QWidget::data’ is private
/home/stesalit/Desktop/cam/webcam.cpp:185: error: within this context
/home/stesalit/Desktop/cam/webcam.cpp:328: error: ‘changepmBKImage’ was not declared in this scope
/home/stesalit/Desktop/cam/webcam.cpp:329: error: no matching function for call to ‘WebCam::repaint(bool)’