Label

前面的文章里面把QLabel批量引入ScrollArea作为预览窗口，这篇把图像填充到QLable的PixelMap展示指定图像。

参数设置

设置QLabel的大小格式

 QWidget* widget = new QWidget;
widget->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
widget->setMinimumSize(QSize(210, 210));

QString msg = "Label_" + QString::number(i);
QLabel* label = new QLabel(msg);
label->setGeometry(QRect(0, 0, widget->width(), widget->height()));//全屏铺满
label->setMinimumSize(QSize(200, 200));
label->setAlignment(Qt::AlignVCenter | Qt::AlignHCenter);

PixelMap填充

重点是PixelMap的填充，所以这里像素值以渐变对象填充了。

// 创建一个渐变对象，并设置渐变色
QLinearGradient gradient(0, 0, 200, 0); // 从左到右的线性渐变
gradient.setColorAt(0, Qt::red);
gradient.setColorAt(0.5, Qt::green);
gradient.setColorAt(1, Qt::blue);

// 创建一个QPixmap，并使用渐变填充
QPixmap pixmap(200, 200);
pixmap.fill(Qt::transparent); // 填充透明背景
QPainter painter(&pixmap);
painter.fillRect(pixmap.rect(), gradient);

label->setPixmap(pixmap);

CV::Mat 到PixelMap填充

这里没有写cv::Mat到PixelMap的映射，因为重点是PixelMap的功能展示，以下是一个Mat到PixelMap对照的例子。

cv::Mat image = cv::imread("1.jpg"); // 替换为您的图像路径
QImage qimage(image.data, image.cols, image.rows, image.step, QImage::Format_RGB888);
qimage = qimage.rgbSwapped();
QSize targetSize(200, 200);
qimage = qimage.scaled(targetSize, Qt::KeepAspectRatio);
QPixmap pixmap = QPixmap::fromImage(qimage);
label->setPixmap(pixmap);

总体代码及效果

#pragma once

#include <QtWidgets/QMainWindow>
#include <QtWidgets>
#include "ui_dcmimgpro.h"

class DcmImgPro : public QMainWindow
{
    Q_OBJECT

public:
    DcmImgPro(QWidget *parent = nullptr);
    ~DcmImgPro();

private:
    Ui::DcmImgProClass ui;
private slots:
    void pushbtn();
    void lineEditset();
private:
    int l_num = 15;
};

class ScrollableWidget:public QWidget
{
public:
    ScrollableWidget(int numWidgets)
    {
        QVBoxLayout* layout = new QVBoxLayout(this);
        for (int i = 0; i < numWidgets; i++)
        {
            QWidget* widget = new QWidget;
            widget->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
            widget->setMinimumSize(QSize(210, 210));

            QString msg = "Label_" + QString::number(i);
            QLabel* label = new QLabel(msg);
            label->setGeometry(QRect(0, 0, widget->width(), widget->height()));//全屏铺满
            label->setMinimumSize(QSize(200, 200));
            label->setAlignment(Qt::AlignVCenter | Qt::AlignHCenter);

            // 创建一个渐变对象，并设置渐变色
            QLinearGradient gradient(0, 0, 200, 0); // 从左到右的线性渐变
            gradient.setColorAt(0, Qt::red);
            gradient.setColorAt(0.5, Qt::green);
            gradient.setColorAt(1, Qt::blue);

            // 创建一个QPixmap，并使用渐变填充
            QPixmap pixmap(200, 200);
            pixmap.fill(Qt::transparent); // 填充透明背景
            QPainter painter(&pixmap);
            painter.fillRect(pixmap.rect(), gradient);

            label->setPixmap(pixmap);

            QVBoxLayout* widgetlayout = new QVBoxLayout(widget);
            widgetlayout->addWidget(label);
            layout->addWidget(widget);
        }
    };

};

#include "dcmimgpro.h"

DcmImgPro::DcmImgPro(QWidget *parent)
    : QMainWindow(parent)
{
    ui.setupUi(this);
    ui.scrollArea->setWidgetResizable(true);
    ScrollableWidget* scrollableWidget = new  ScrollableWidget(l_num);
    ui.scrollArea->setWidget(scrollableWidget);
    ui.lineEdit->setText(QString::number(l_num));
    connect(ui.pushButton, SIGNAL(clicked()), this, SLOT(pushbtn()));
    connect(ui.lineEdit, SIGNAL(editingFinished()), this, SLOT(lineEditset()));
    //textChanged   cursorPositionChanged
    //editingFinished  selectionChanged returnPressed() 
}

void DcmImgPro::pushbtn()
{
    ui.scrollArea->setWidget(nullptr);
    ScrollableWidget* scrollableWidget = new  ScrollableWidget(l_num);
    ui.scrollArea->setWidget(scrollableWidget);
}

void DcmImgPro::lineEditset()
{
    l_num = ui.lineEdit->text().toInt();
}
DcmImgPro::~DcmImgPro()
{
 
}