Qt：QtPainter设置画刷-蒲公英云

Qt：QtPainter设置画刷

墨蓝 2022-10-24 11:45 157阅读 0赞

/*
* 1、新建QT GUI，基类选择QWidget，取消“创建界面”
* 2、添加资源文件qtlogn：在项目之下添加一个“resources”文件，里面存放”qtblog.png”，然后
* 文件—>新建文件/项目—->Qt—-> Qt Resource File
* 3、在widget.h中添加#include 和重写绘画事件定义：
* protected:
void paintEvent(QPaintEvent *event);
* 4、在widget.cpp中添加重绘事件

1、QRadialGradient

void Widget::paintEvent(QPaintEvent *event)
{
    QPainter painter;
    painter.begin(this);
    QRadialGradient gradient(50, 50, 50, 50, 50);
    gradient.setColorAt(0, QColor::fromRgbF(0, 1, 0, 1));
    gradient.setColorAt(1, QColor::fromRgbF(0, 0, 0, 0));
    QBrush brush(gradient);
    painter.setBrush(brush);
    painter.drawRect(0, 0, 100, 100);
    painter.end();
}

2、设置画刷为pixmap文件

void Widget::paintEvent(QPaintEvent *event)
{
    QPainter painter;
    painter.begin(this);
    QPixmap pixmap("F:\\MyCode\\brush\\resources\\qtblog.png");
    int w = pixmap.width();
    int h = pixmap.height();
    pixmap.scaled(w, h, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
    QBrush brush(pixmap);   //设置画刷为pixmap文件：也就是用pixmap图形填充矩形
    painter.setBrush(brush);
    painter.drawRect(0, 0, w, h);
    painter.end();
}

3、设置画刷的填充颜色

void Widget::paintEvent(QPaintEvent *event)
{
    QPainter painter;
    painter.begin(this);
    painter.setPen(Qt::blue);
    painter.setBrush(QBrush(Qt::green, Qt::Dense3Pattern));
    painter.drawEllipse(10, 10, 100,100);
    painter.setBrush(Qt::NoBrush);
    painter.drawEllipse(80, 10, 100, 100);
    painter.end();
}