qt画笔的简单应用

//painter.h

#ifndef PAINTER_H

#define PAINTER_H

#include <QWidget>

#include<QPen>

#include<QBrush>

class painter : public QWidget

{

    Q_OBJECT

public:

    explicit painter(QWidget *parent = 0);

    ~painter();

     enum Shape{Line,Rectangle,RoundRect,Ellipse,Polygon,Polyline,Points,Arc,Path,Text,Pixmap};

     void setShape(Shape);

     void setPen(QPen);

     void setBrush(QBrush);

     void setFillRule(Qt::FillRule);

     void paintEvent(QPaintEvent *);

signals:

public slots:

private:

     Shape shape;//就是定义的枚举

     QPen pen;

     QBrush brush;

     Qt::FillRule fillRule;//填充规则

};

#endif // PAINTER_H

#include "painter.h"

#include<QPainter>

painter::painter(QWidget *parent) : QWidget(parent)

{

    setPalette(QPalette(Qt::white));//set background to white

    setAutoFillBackground(true);

    setMinimumSize(400,400);

}

void painter::setShape(Shape s)

{

    shape=s;

    update();

}

void painter::setPen(QPen p)

{

    pen=p;

    update();

}

void painter::setBrush(QBrush b)

{

    brush=b;

    update();

}

void painter::setFillRule(Qt::FillRule f)

{

    fillRule=f;

    update();

}

void painter::paintEvent(QPaintEvent *)

{

    QPainter p(this);//次函数内调用的函数是Qpainter类的成员函数

    p.setPen(pen);

    p.setBrush(brush);

    QRect rect(50,100,300,200);

    static const QPoint points[4]={QPoint(150,100),QPoint(300,150),QPoint(350,250),QPoint(100,300)};

    int startAngle=30*16;

    int spanAngle=120*16;

    QPainterPath path;

    path.addRect(150,150,100,100);//==path.moveTo(0,0);

    path.moveTo(100,100);//移动到固定位置

    path.cubicTo(300,100,200,200,300,300);

    path.cubicTo(100,300,200,200,100,100);

    path.setFillRule(fillRule);

    switch(shape)

    {

        case Line:                                         	//直线

            p.drawLine(rect.topLeft(),rect.bottomRight()); 	break;

        case Rectangle:                                    	//长方形

            p.drawRect(rect);	break;

        case RoundRect:                                    	//圆角方形

            p.drawRoundRect(rect); 	break;

        case Ellipse:                                      	//椭圆形

            p.drawEllipse(rect); 	break;

        case Polygon:                                      	//多边形

            p.drawPolygon(points,4); 	break;

        case Polyline:                                      //多边线

            p.drawPolyline(points,4); 	break;

        case Points:                                      	//点

            p.drawPoints(points,4); 	break;

        case Arc:                                          	//弧

            p.drawArc(rect,startAngle,spanAngle);	 break;

        case Path:                                         	//路径

            p.drawPath(path); 	break;

        case Text:                                        	//文字

            p.drawText(rect,Qt::AlignCenter,tr("Hello Qt!"));	break;

        case Pixmap:                                      	//图片

            p.drawPixmap(150,150,QPixmap("butterfly.png")); 	break;

        default: 	break;

    }

}

painter::~painter()

{

}

//widget.h

#ifndef WIDGET_H

#define WIDGET_H

#include <QWidget>

#include"painter.h"

#include<QLabel>

#include<QComboBox>

#include<QSpinBox>

#include<QPushButton>

#include<QGridLayout>

#include<QGradient>//渐变

class Widget : public QWidget

{

    Q_OBJECT

public:

    Widget(QWidget *parent = 0);

    ~Widget();

private:

    painter *pter;

    QLabel *shapeLabel;

    QComboBox *shapeComboBox;

    QLabel *penWidthLabel;

    QSpinBox *penWidthSpinBox;

    QLabel *penColorLabel;

    QFrame *penColorFrame;

    QPushButton *penColorBtn;

    QLabel *penStyleLabel;

    QComboBox *penStyleComboBox;

    QLabel *penCapLabel;

    QComboBox *penCapComboBox;

    QLabel *penJoinLabel;

    QComboBox *penJoinComboBox;

    QLabel *fillRuleLabel;

    QComboBox *fillRuleComboBox;

    QLabel *spreadLabel;

    QComboBox *spreadComboBox;

    QGradient::Spread spread;

    QLabel *brushStyleLabel;

    QComboBox *brushStyleComboBox;

    QLabel *brushColorLabel;

    QFrame *brushColorFrame;

    QPushButton *brushColorBtn;

    QGridLayout *rightLayout;

protected slots:

    void ShowShape(int);

    void ShowPenWidth(int);

    void ShowPenColor();

    void ShowPenStyle(int);

    void ShowPenCap(int);

    void ShowPenJoin(int);

    void ShowSpreadStyle();

    void ShowFillRule();

    void ShowBrushColor();

    void ShowBrush(int);

};

#endif // WIDGET_H

#include "widget.h"

#include<QColorDialog>

#include<QPen>

Widget::Widget(QWidget *parent)

    : QWidget(parent)

{

    pter=new painter;

    shapeLabel =new QLabel(tr("形状："));            //形状选择下拉列表框

    shapeComboBox =new QComboBox;

    shapeComboBox->addItem(tr("Line"),painter::Line);//原来定义的枚举可以这样用

    shapeComboBox->addItem(tr("Rectangle"),painter::Rectangle);

    shapeComboBox->addItem(tr("RoundedRect"),painter::RoundRect);

    shapeComboBox->addItem(tr("Ellipse"),painter::Ellipse);

    shapeComboBox->addItem(tr("Polygon"),painter::Polygon);

    shapeComboBox->addItem(tr("Polyline"),painter::Polyline);

    shapeComboBox->addItem(tr("Points"),painter::Points);

    shapeComboBox->addItem(tr("Arc"),painter::Arc);

    shapeComboBox->addItem(tr("Path"),painter::Path);

    shapeComboBox->addItem(tr("Text"),painter::Text);

    shapeComboBox->addItem(tr("Pixmap"),painter::Pixmap);

    connect(shapeComboBox,SIGNAL(activated(int)),this,SLOT(ShowShape (int)));

    penColorLabel =new QLabel(tr("画笔颜色："));     	//画笔颜色选择控件

    penColorFrame =new QFrame;

    penColorFrame->setFrameStyle(QFrame::Panel|QFrame::Sunken);

    penColorFrame->setAutoFillBackground(true);

    penColorFrame->setPalette(QPalette(Qt::blue));

    penColorBtn =new QPushButton(tr("更改"));

    connect(penColorBtn,SIGNAL(clicked()),this,SLOT(ShowPenColor()));

    penWidthLabel =new QLabel(tr("画笔线宽："));     	//画笔线宽选择控件

    penWidthSpinBox =new QSpinBox;

    penWidthSpinBox->setRange(0,20);

    connect(penWidthSpinBox,SIGNAL(valueChanged(int)),this,SLOT (ShowPenWidth(int)));

    penStyleLabel =new QLabel(tr("画笔风格："));     	//画笔风格选择下拉列表框

    penStyleComboBox =new QComboBox;

    penStyleComboBox->addItem(tr("SolidLine"),static_cast<int>(Qt::SolidLine));

    penStyleComboBox->addItem(tr("DashLine"),static_cast<int>(Qt::DashLine));

    penStyleComboBox->addItem(tr("DotLine"),static_cast<int>(Qt::DotLine));

    penStyleComboBox->addItem(tr("DashDotLine"),static_cast<int>(Qt::DashDotLine));

    penStyleComboBox->addItem(tr("DashDotDotLine"),static_cast<int>(Qt::DashDotDotLine));

    penStyleComboBox->addItem(tr("CustomDashLine"),static_cast<int>(Qt::CustomDashLine));

    connect(penStyleComboBox,SIGNAL(activated(int)),this,SLOT (ShowPenStyle(int)));

    penCapLabel =new QLabel(tr("画笔顶帽："));        //画笔顶端风格选择下拉列表框

        penCapComboBox =new QComboBox;

        penCapComboBox->addItem(tr("SquareCap"),Qt::SquareCap);

        penCapComboBox->addItem(tr("FlatCap"),Qt::FlatCap);

        penCapComboBox->addItem(tr("RoundCap"),Qt::RoundCap);

        connect(penCapComboBox,SIGNAL(activated(int)),this,SLOT(ShowPenCap (int)));

        penJoinLabel =new QLabel(tr("画笔连接点："));     //画笔连接点风格选择下拉列表框

        penJoinComboBox =new QComboBox;

        penJoinComboBox->addItem(tr("BevelJoin"),Qt::BevelJoin);

        penJoinComboBox->addItem(tr("MiterJoin"),Qt::MiterJoin);

        penJoinComboBox->addItem(tr("RoundJoin"),Qt::RoundJoin);

        connect(penJoinComboBox,SIGNAL(activated(int)),this,SLOT(ShowPenJoin (int)));

        fillRuleLabel =new QLabel(tr("填充模式："));    	//填充模式选择下拉列表框

        fillRuleComboBox =new QComboBox;

        fillRuleComboBox->addItem(tr("Odd Even"),Qt::OddEvenFill);

        fillRuleComboBox->addItem(tr("Winding"),Qt::WindingFill);

        connect(fillRuleComboBox,SIGNAL(activated(int)),this,SLOT (ShowFillRule()));

        spreadLabel =new QLabel(tr("铺展效果："));    	//铺展效果选择下拉列表框

        spreadComboBox =new QComboBox;

        spreadComboBox->addItem(tr("PadSpread"),QGradient::PadSpread);

        spreadComboBox->addItem(tr("RepeatSpread"),QGradient::RepeatSpread);

        spreadComboBox->addItem(tr("ReflectSpread"),QGradient:: ReflectSpread);

        connect(spreadComboBox,SIGNAL(activated(int)),this,SLOT (ShowSpreadStyle()));

        brushColorLabel =new QLabel(tr("画刷颜色："));   	//画刷颜色选择控件

        brushColorFrame =new QFrame;

        brushColorFrame->setFrameStyle(QFrame::Panel|QFrame::Sunken);

        brushColorFrame->setAutoFillBackground(true);

        brushColorFrame->setPalette(QPalette(Qt::green));

        brushColorBtn =new QPushButton(tr("更改"));

        connect(brushColorBtn,SIGNAL(clicked()),this,SLOT (ShowBrushColor()));

        brushStyleLabel =new QLabel(tr("画刷风格："));   	//画刷风格选择下拉列表框

        brushStyleComboBox =new QComboBox;

        brushStyleComboBox->addItem(tr("SolidPattern"),static_cast<int>(Qt::SolidPattern));

        brushStyleComboBox->addItem(tr("Dense1Pattern"),static_cast<int>(Qt::Dense1Pattern));

        brushStyleComboBox->addItem(tr("Dense2Pattern"),static_cast<int>(Qt::Dense2Pattern));

        brushStyleComboBox->addItem(tr("Dense3Pattern"),static_cast<int>(Qt::Dense3Pattern));

        brushStyleComboBox->addItem(tr("Dense4Pattern"),static_cast<int>(Qt::Dense4Pattern));

        brushStyleComboBox->addItem(tr("Dense5Pattern"),static_cast<int>(Qt::Dense5Pattern));

        brushStyleComboBox->addItem(tr("Dense6Pattern"),static_cast<int>(Qt::Dense6Pattern));

        brushStyleComboBox->addItem(tr("Dense7Pattern"),static_cast<int>(Qt::Dense7Pattern));

        brushStyleComboBox->addItem(tr("HorPattern"),static_cast<int>(Qt::HorPattern));

        brushStyleComboBox->addItem(tr("VerPattern"),static_cast<int>(Qt::VerPattern));

        brushStyleComboBox->addItem(tr("CrossPattern"),static_cast<int>(Qt::CrossPattern));

        brushStyleComboBox->addItem(tr("BDiagPattern"),static_cast<int>(Qt::BDiagPattern));

        brushStyleComboBox->addItem(tr("FDiagPattern"),static_cast<int>(Qt::FDiagPattern));

        brushStyleComboBox->addItem(tr("DiagCrossPattern"),static_cast<int>(Qt:: DiagCrossPattern));

        brushStyleComboBox->addItem(tr("LinearGradientPattern"),static_cast<int>(Qt:: LinearGradientPattern));

        brushStyleComboBox->addItem(tr("ConicalGradientPattern"),static_cast<int>(Qt:: ConicalGradientPattern));

        brushStyleComboBox->addItem(tr("RadialGradientPattern"),static_cast<int>(Qt:: RadialGradientPattern));

        brushStyleComboBox->addItem(tr("TexturePattern"),static_cast<int>(Qt::TexturePattern));

        connect(brushStyleComboBox,SIGNAL(activated(int)),this,SLOT (ShowBrush(int)));

        rightLayout =new QGridLayout;                   //控制面板的布局

        rightLayout->addWidget(shapeLabel,0,0);

        rightLayout->addWidget(shapeComboBox,0,1);

        rightLayout->addWidget(penColorLabel,1,0);

        rightLayout->addWidget(penColorFrame,1,1);

        rightLayout->addWidget(penColorBtn,1,2);

        rightLayout->addWidget(penWidthLabel,2,0);

        rightLayout->addWidget(penWidthSpinBox,2,1);

        rightLayout->addWidget(penStyleLabel,3,0);

        rightLayout->addWidget(penStyleComboBox,3,1);

        rightLayout->addWidget(penCapLabel,4,0);

        rightLayout->addWidget(penCapComboBox,4,1);

        rightLayout->addWidget(penJoinLabel,5,0);

        rightLayout->addWidget(penJoinComboBox,5,1);

        rightLayout->addWidget(fillRuleLabel,6,0);

        rightLayout->addWidget(fillRuleComboBox,6,1);

        rightLayout->addWidget(spreadLabel,7,0);

        rightLayout->addWidget(spreadComboBox,7,1);

        rightLayout->addWidget(brushColorLabel,8,0);

        rightLayout->addWidget(brushColorFrame,8,1);

        rightLayout->addWidget(brushColorBtn,8,2);

        rightLayout->addWidget(brushStyleLabel,9,0);

        rightLayout->addWidget(brushStyleComboBox,9,1);

        QHBoxLayout *mainLayout =new QHBoxLayout(this);   	//整体的布局

        mainLayout->addWidget(pter);

        mainLayout->addLayout(rightLayout);

        mainLayout->setStretchFactor(pter,1);

        mainLayout->setStretchFactor(rightLayout,0);

        ShowShape(shapeComboBox->currentIndex());     		//显示默认的图形

}

void Widget::ShowShape(int value)

{

    painter::Shape shape=painter::Shape(shapeComboBox->itemData(value,Qt::UserRole).toInt());

    pter->setShape(shape);

}

void Widget::ShowPenColor()

{

    QColor color=QColorDialog::getColor(static_cast<int>(Qt::blue));

    penColorFrame->setPalette(QPalette(color));

    int value=penWidthSpinBox->value();

    Qt::PenStyle stype=Qt::PenStyle(penStyleComboBox->itemData(penStyleComboBox->currentIndex(),Qt::UserRole).toInt());

    Qt::PenCapStyle cap=Qt::PenCapStyle(penCapComboBox->itemData(penCapComboBox->currentIndex(),Qt::UserRole).toInt());

    Qt::PenJoinStyle join=Qt::PenJoinStyle(penJoinComboBox->itemData(penJoinComboBox->currentIndex(),Qt::UserRole).toInt());

    pter->setPen(QPen(color,value,stype,cap,join));

}

void Widget::ShowPenWidth(int value)

{

    QColor color = penColorFrame->palette().color(QPalette::Window);

    Qt::PenStyle style = Qt::PenStyle(penStyleComboBox->itemData(penStyleComboBox->currentIndex(),Qt::UserRole).toInt());

    Qt::PenCapStyle cap = Qt::PenCapStyle(penCapComboBox->itemData(penCapComboBox->currentIndex(),Qt::UserRole).toInt());

    Qt::PenJoinStyle join=Qt::PenJoinStyle(penJoinComboBox->itemData(penJoinComboBox->currentIndex(),Qt::UserRole).toInt());

    pter->setPen(QPen(color,value,style,cap,join));

}

void Widget::ShowPenStyle(int styleValue)

{

    QColor color = penColorFrame->palette().color(QPalette::Window);

    int value = penWidthSpinBox->value();

    Qt::PenStyle style = Qt::PenStyle(penStyleComboBox->itemData(styleValue,Qt::UserRole).toInt());

    Qt::PenCapStyle cap = Qt::PenCapStyle(penCapComboBox->itemData(penCapComboBox->currentIndex(),Qt::UserRole).toInt());

    Qt::PenJoinStyle join=Qt::PenJoinStyle(penJoinComboBox->itemData(penJoinComboBox->currentIndex(),Qt::UserRole).toInt());

    pter->setPen(QPen(color,value,style,cap,join));

}

void Widget::ShowPenCap(int capValue)

{

    QColor color = penColorFrame->palette().color(QPalette::Window);

    int value = penWidthSpinBox->value();

    Qt::PenStyle style = Qt::PenStyle(penStyleComboBox->itemData(penStyleComboBox->currentIndex(),Qt::UserRole).toInt());

    Qt::PenCapStyle cap = Qt::PenCapStyle(penCapComboBox->itemData(capValue,Qt::UserRole).toInt());

    Qt::PenJoinStyle join=Qt::PenJoinStyle(penJoinComboBox->itemData(penJoinComboBox->currentIndex(),Qt::UserRole).toInt());

    pter->setPen(QPen(color,value,style,cap,join));

}

void Widget::ShowPenJoin(int joinValue)

{

    QColor color = penColorFrame->palette().color(QPalette::Window);

    int value = penWidthSpinBox->value();

    Qt::PenStyle style = Qt::PenStyle(penStyleComboBox->itemData(penStyleComboBox->currentIndex(),Qt::UserRole).toInt());

    Qt::PenCapStyle cap = Qt::PenCapStyle(penCapComboBox->itemData(penCapComboBox->currentIndex(),Qt::UserRole).toInt());

    Qt::PenJoinStyle join=Qt::PenJoinStyle(penJoinComboBox->itemData(joinValue,Qt::UserRole).toInt());

    pter->setPen(QPen(color,value,style,cap,join));

}

void Widget::ShowFillRule()

{

    Qt::FillRule rule = Qt::FillRule(fillRuleComboBox->itemData(fillRuleComboBox->currentIndex(),Qt::UserRole).toInt());

    pter->setFillRule(rule);

}

void Widget::ShowSpreadStyle()

{

    spread = QGradient::Spread(spreadComboBox->itemData(spreadComboBox->currentIndex(),Qt::UserRole).toInt());

}

void Widget::ShowBrushColor()

{

    QColor color = QColorDialog::getColor(static_cast<int>(Qt::blue));

    brushColorFrame->setPalette(QPalette(color));

    ShowBrush(brushStyleComboBox->currentIndex());

}

void Widget::ShowBrush(int value)

{

    QColor color = brushColorFrame->palette().color(QPalette::Window);

    Qt::BrushStyle style = Qt::BrushStyle(brushStyleComboBox->itemData(value,Qt::UserRole).toInt());

    if(style == Qt::LinearGradientPattern)

    {

        QLinearGradient linearGradient(0,0,400,400);

        linearGradient.setColorAt(0.0,Qt::white);

        linearGradient.setColorAt(0.2,color);

        linearGradient.setColorAt(1.0,Qt::black);

        linearGradient.setSpread(spread);

        pter->setBrush(linearGradient);

    }

    else if(style == Qt::RadialGradientPattern)

    {

        QRadialGradient radialGradient(200,200,150,150,100);

        radialGradient.setColorAt(0.0,Qt::white);

        radialGradient.setColorAt(0.2,color);

        radialGradient.setColorAt(1.0,Qt::black);

        radialGradient.setSpread(spread);

        pter->setBrush(radialGradient);

    }

    else if(style == Qt::ConicalGradientPattern)

    {

        QConicalGradient conicalGradient(200,200,30);

        conicalGradient.setColorAt(0.0,Qt::white);

        conicalGradient.setColorAt(0.2,color);

        conicalGradient.setColorAt(1.0,Qt::black);

        pter->setBrush(conicalGradient);

    }

    else if(style == Qt::TexturePattern)

    {

        pter->setBrush(QBrush(QPixmap("butterfly.png")));

    }

    else

    {

        pter->setBrush(QBrush(color,style));

    }

}

Widget::~Widget()

{

}

#include "widget.h"

#include <QApplication>

int main(int argc, char *argv[])

{

    QApplication a(argc, argv);

    Widget w;

    w.show();

    return a.exec();

}