样式图：

.ui

在sloem1.ui文件中，拖入一个label控件，

头文件.h

#include "QtGui/QPainter.h"
#include "QtCore/QTimer.h"

protected:
	bool eventFilter(QObject *obj,QEvent *event);
	void labelPaint();
	
public slots:
//动态曲线
	void drawCoordinateSystem(QPainter *painter);
	void drawDynamicSpline(QPainter *painter);
	void drawDynamicPiont();//动态点

源文件.cpp

static int count = 60;//统一改变，动态曲线所有参数
static int i = 0;//动态曲线点数，所要调用的参数
static int num = 99;//动态曲线点数（不同要求可修改）
static double dynamicPoint[99];//存储动态曲线点数的数组，移动时需要存储以前的数据，（不同要求需修改）
static double interval = count * 12 * 1.0 /( num-1 );//每一个点之间的间隔

sloem1::sloem1(QWidget* pParent, const QString& rszName)
				: SlGfwDialogForm(pParent, rszName)
{
	setupUi(this);
	
	this->label->installEventFilter(this->label);
	
	QTimer * timer = new QTimer(this);
	QObject::connect(timer,
					SIGNAL(timeout()),
					this,
					SLOT(update()));
	timer->start(1000);//毫秒
} // <-- sloem1::sloem1 ()

//事件过滤器
bool sloem1::eventFilter(QObject *watched, QEvent *event)
{
	if(watched == this->label && event->type() == QEvent::Paint)
	{
		labelPaint();
	}
	//交由QWidget的事件过滤器处理
	return QWidget::eventFilter(watched,event);
}

//==============================动态曲线图============================
void sloem1::labelPaint()
{
	int width  = this -> width ();//标准ui宽度559
	int height = this -> height();//标准ui高度394
	int side   = qMin( width, height ) / 2;

	QPainter painter( this->label );
	painter.setRenderHints ( QPainter::Antialiasing | QPainter::TextAntialiasing );//抗锯齿
	painter.translate ( 165, 60 );//图形中心点，默认中心点左上角
	painter.scale (side / 520.0, side / 520.0);//图形大小

	//动态曲线
	drawCoordinateSystem(&painter);
	drawDynamicPiont();
	drawDynamicSpline(&painter);
}


void sloem1::drawCoordinateSystem(QPainter *painter)
{
	//int count = 60;//局部变量，统一改变所有参数
	painter->save();
	painter->setPen(Qt::black);
	painter->drawLine(QPointF(-count*6,count*3),QPointF( count*6, count*3  ));//x轴
	painter->drawLine(QPointF(-count*6,count*3),QPointF(-count*6,-count*2.5));//y轴

    painter->setPen(Qt::DashLine);//虚线
    painter->drawLine(QPointF(-count*6, count*2),QPointF(count*6, count*2));
    painter->drawLine(QPointF(-count*6, count*1),QPointF(count*6, count*1));
    painter->drawLine(QPointF(-count*6, count*0),QPointF(count*6, count*0));
    painter->drawLine(QPointF(-count*6,-count*1),QPointF(count*6,-count*1));
    painter->drawLine(QPointF(-count*6,-count*2),QPointF(count*6,-count*2));

	QFont font;//字体
	font.setPixelSize(40);
	painter->setFont(font);
    painter->drawText(-count*7.2, count*2.2,"1%" );
    painter->drawText(-count*7.2, count*1.2,"2%");
    painter->drawText(-count*7.2, count*0.2,"3%");
    painter->drawText(-count*7.2,-count*0.8,"4%");
    painter->drawText(-count*7.2,-count*1.8,"5%");
    painter->restore();
}

void sloem1::drawDynamicPiont()
{
	if( i < num )//坐标轴上点没有满时，
	{
		dynamicPoint[i] = qrand()%180;
	}
	i = i + 1;
	if( i == num + 1 )//坐标轴上点已满，全体向左移动
	{
		i = i - 2;//坐标轴最后一个点
		for( int j = 0; j < num - 1; j++ )
		{
			dynamicPoint[j] = dynamicPoint[j+1];
		}
		dynamicPoint[i] = qrand()%180;
		i = i + 1;//不再进入坐标轴没满的循环
	}
}

void sloem1::drawDynamicSpline(QPainter *painter)
{
	painter->save();
	QPen pen;
	pen.setColor(Qt::white);
	pen.setWidth(10);
	painter->setPen(pen);
	//painter->drawPoint(QPointF(-count*4,count*3));//坐标原点
	;
	//把横坐标按照点数分配；count*8/num，总长度/点数

	for( int j = 0; j < i; j++ )
	{
		painter->drawPoint(QPointF(interval*j-interval*((num-1)/2),dynamicPoint[j]));//
	}

	pen.setColor(QColor(255,192,203));
	pen.setWidth(4);
	painter->setPen(pen);

	//把点连成折线
	if( i != 0 )
	{
		for( int k = 0; k < i-1; k++ )
		{
			painter->drawLine(QPointF(interval*k-interval*((num-1)/2),dynamicPoint[k]),
				QPointF(QPointF(interval*(k+1)-interval*((num-1)/2),dynamicPoint[k+1])));
		}
	}
	painter->restore();
}