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关于窗口画图的问题：窗口闪了一下又突然消失
#include <stdio.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <stdlib.h> #include <qwidget.h> #include <qdialog.h> #include <qapplication.h> #include <qpainter.h> #include <qpoint.h> #include <qcolor.h> #include <qpen.h> #include "qpaintwidget.h" ConnectWidget::ConnectWidget(QWidget *parent, const char *name) :QWidget(parent,name) { setBackgroundColor(white); }; ConnectWidget::~ConnectWidget() { //delete[] points; }; void ConnectWidget::initpoints(QPoint *psrc,int num,int mode) { //这里应该无所谓的 int i; for(i=0;i<num;i++) this->points =psrc;
pointnum=num;
labelmode=mode;
//这里应该无所谓的
};
void ConnectWidget::paintEvent(QPaintEvent* )
{
//这里是画图的，应该关系不大
QPainter paint(this);
QPen pen;
//draw the axis
//black,width 3,solid
pen.setWidth(2);
pen.setStyle(SolidLine);
pen.setColor(black);
paint.setPen(pen);
paint.drawLine(QPoint(50,50),QPoint(50,400));
paint.drawLine(QPoint(50,400),QPoint(600,400));
paint.drawLine(QPoint(50,50),QPoint(45,60));
paint.drawLine(QPoint(50,50),QPoint(55,60));
paint.drawLine(QPoint(590,395),QPoint(600,400));
paint.drawLine(QPoint(590,405),QPoint(600,400));
//draw the lines
pen.setWidth(1);
pen.setStyle(SolidLine);
pen.setColor(red);
paint.setPen(pen);
for(int i=0;i<pointnum-1;i++)
{
paint.drawLine(points, points[i+1]);
}
pen.setWidth(2);
pen.setStyle(SolidLine);
pen.setColor(green);
paint.setPen(pen);
switch(labelmode)
{
case 1:
paint.drawText(QPoint(500,50),"Time diagram",-1);
break;
case 2:
paint.drawText(QPoint(500,50),"Speed diagram",-1);
break;
case 3:
paint.drawText(QPoint(500,50),"Distance diagram",-1);
break;
case 4:
paint.drawText(QPoint(500,50),"Pulse diagram",-1);
break;
default:
break;
}
//这里是画图的，应该关系不大
};
为什么我程序中
ConnectWidget cw;
cw.initpoints(points,num,1);
cw.resize(640,480);
cw.show();
窗口只是闪了一下就消失了，如果改成
ConnectWidget cw;
cw.initpoints(points,num,1);
cw.resize(640,480);
cw.show();
QMessageBox::information( this, "Application name","OK");
窗口就会显示出来。
请问如何不加QMessageBox::information( this, "Application name","OK");仍然可以显示出窗口，直到把窗口关闭。[ 此贴被inshine在2006-06-21 20:50重新编辑 ]
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