QT clipboard qclipboard copy paste custom data

One 、 Common data types

QClipboard Class provides an operation interface for the operating system clipboard , The most common way is to copy and paste text , As shown in the following example

QClipboard *clipboard = QGuiApplication::clipboard();
QString originalText = clipboard->text(); // Get the text in the clipboard （ Paste ）
...
clipboard->setText(newText); // Write text into the clipboard （ Copy ）

QClipboard Several sets of functions are provided to access common data types , If the data type we want to operate on is QString、QImage or QPixmap, You can use these interfaces directly .

QImage image(QClipboard::Mode mode = Clipboard) const
void setImage(const QImage &image, QClipboard::Mode mode = Clipboard)

QPixmap pixmap(QClipboard::Mode mode = Clipboard) const
void setPixmap(const QPixmap &pixmap, QClipboard::Mode mode = Clipboard)

QString text(QClipboard::Mode mode = Clipboard) const
QString text(QString &subtype, QClipboard::Mode mode = Clipboard) const
void setText(const QString &text, QClipboard::Mode mode = Clipboard)

Two 、 Custom data types

If you want to write custom data types into the system clipboard , And you can read the customized data types we wrote in from the system clipboard , have access to QMimeData+QDataStream. Here is a simple example .

#include <QApplication>
#include <QPushButton>
#include <QClipboard>
#include <QMimeData>
#include <QDebug>

struct Device
{
    int index;
    QString text;
};

void setDeviceToClipboard(struct Device &d)
{
    QByteArray itemData;
    QDataStream dataStream(&itemData, QIODevice::WriteOnly);
    dataStream << d.index;
    dataStream << d.text;

    QMimeData *mimeData = new QMimeData;
    mimeData->setData("application/itemdata", itemData);

    QClipboard *clipboard = QApplication::clipboard();
    clipboard->setMimeData(mimeData);
}

struct Device *getDeviceFromClipboard()
{
    const QClipboard *clipboard = QApplication::clipboard();
    const QMimeData *mimeData = clipboard->mimeData();

    if (mimeData->hasFormat("application/itemdata"))
    {
        QByteArray itemData = mimeData->data("application/itemdata");
        QDataStream dataStream(&itemData, QIODevice::ReadOnly);

        struct Device *pDevice = new struct Device;

        dataStream >> pDevice->index;
        dataStream >> pDevice->text;

        return pDevice;
    }
    return nullptr;
}

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    struct Device d1;
    d1.index = 1;
    d1.text = "device1";

    // Write custom data to the clipboard 
    setDeviceToClipboard(d1);

    // Read custom data from the clipboard 
    struct Device *pDevice = getDeviceFromClipboard();
    if (pDevice != nullptr)
    {
        qDebug() << pDevice->index;
        qDebug() << pDevice->text;
    }

    return 0;
}