技術標籤：mysqlsvneventunitywindows

/*
* 1、新建QT GUI， 基類選擇QWidget，取消“建立介面”
* 2、新增資原始檔qtlogn：在專案之下新增一個“resources”檔案，裡面存放"qtblog.png"，然後
* 檔案-->新建檔案/專案--->Qt---> Qt Resource File
* 3、在widget.h中新增#include <QPainter>和重寫繪畫事件定義：
* protected:
void paintEvent(QPaintEvent *event);
* 4、在widget.cpp中編寫重繪事件

1、座標原點移動：

void Widget::paintEvent(QPaintEvent *event)
{
    QImage image("F:\\MyCode\\qtblog.png");

    QPainter painter(this);  //this表示啟用畫筆
    painter.setPen(QPen(Qt::blue, 1, Qt::DashLine));
    painter.drawRect(0, 0, 100, 100);

    QTransform transform;
    transform.translate(50, 50);  //將座標從當前座標原點沿著x軸前進50，沿著y軸前進50

    painter.setTransform(transform);
    painter.drawImage(0, 0, image);
    painter.end();
}
 

2、座標系統旋轉rotate

void Widget::paintEvent(QPaintEvent *event)
{
    QImage image("F:\\MyCode\\qtblog.png");

    QPainter painter(this);  //this表示啟用畫筆
    painter.setPen(QPen(Qt::blue, 1, Qt::DashLine));
    painter.drawRect(0, 0, 100, 100);

    QTransform transform;
    transform.translate(50, 50);  //座標沿著x軸前進50，沿著y軸前進50
    transform.rotate(45);  //預設座標沿著z軸旋轉
   //  transform.rotate(70); 
    transform.rotate(45,Qt::ZAxis);
    painter.setTransform(transform);
    painter.drawImage(0, 0, image);
    painter.end();
}
 

void Widget::paintEvent(QPaintEvent *event)
{
    QImage image("F:\\MyCode\\qtblog.png");

    QPainter painter(this);  //this表示啟用畫筆
    painter.setPen(QPen(Qt::blue, 1, Qt::DashLine));
    painter.drawRect(0, 0, 100, 100);

    QTransform transform;
    transform.translate(50, 50);  //座標沿著x軸前進50，沿著y軸前進50
    transform.rotate(70,Qt::YAxis);
    painter.setTransform(transform);
    painter.drawImage(0, 0, image);
    painter.end();
}

void Widget::paintEvent(QPaintEvent *event)
{
    QImage image("F:\\MyCode\\qtblog.png");

    QPainter painter(this);  //this表示啟用畫筆
    painter.setPen(QPen(Qt::blue, 1, Qt::DashLine));
    painter.drawRect(0, 0, 100, 100);

    QTransform transform;
    transform.translate(50, 50);  //座標沿著x軸前進50，沿著y軸前進50
    transform.rotate(80,Qt::XAxis);
    painter.setTransform(transform);  //設定當前旋轉座標為畫筆座標
    painter.drawImage(0, 0, image);
    painter.end();
}

3、座標縮放：從而實現圖形縮放

void Widget::paintEvent(QPaintEvent *event)
{
    QImage image("F:\\MyCode\\qtblog.png");

    QPainter painter(this);  //this表示啟用畫筆
    painter.setPen(QPen(Qt::blue, 1, Qt::DashLine));
    painter.drawRect(0, 0, 100, 100);

    QTransform transform;
    transform.translate(50, 50);
    transform.rotate(45);
    transform.scale(0.5, 0.5);  //橫向和縱向的縮放比例，大於1放大，小於1縮小

    painter.setTransform(transform);
    painter.drawImage(0, 0, image);
    painter.end();
}

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