如果您尝试旋转90度，这就是代码

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QFileDialog>
#include <QtDebug>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent),ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    fileName = QFileDialog::getOpenFileName(this,tr("Open File"),"/home",tr("Images (*.png *.xpm *.jpg *.jpeg *.png)"));
    QImage image = QImage(fileName);
    makeRotate(image);
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::makeRotate(QImage originalImage)
{
    QImage inImage = originalImage;    // Copies the original image into a new QImage object.


    int width = originalImage.width();
    int height = originalImage.height();

    QTransform rotate;
    rotate.rotate(90);
    inImage = inImage.transformed(rotate);


    //a double for loop

    //first loop through the HEIGHT OF inImage  (width of newImage)
    for (int i = 0; i < width; i++)
    {
        //loop through the WIDTH OF inImage  (height of newImage)
        for (int j = 0; j < height; j++)
        {
            //set the pixel
            QRgb rgb = originalImage.pixel(i,j);
            inImage.setPixel(j,i,(rgb));
        }
    }
    QString str = QFileDialog::getSaveFileName(this,fileName);
    inImage.save(str);

    qDebug() << inImage.size();
}

您需要确保尺寸正确，并且如果更改宽度和高度计数器（如我在上面的代码中所做的那样），则代码可以很好地复制图像。