話不多說直接上程式碼，一看就懂

注意：當使用管理員許可權執行qt creator時，程式可能無法檢測到拖拽事件！

widget.h  檔案

class Widget : public QWidget
{
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = 0);
    ~Widget();
protected:
    virtual void dropEvent(QDropEvent *event) override;
    virtual void dragEnterEvent(QDragEnterEvent *event) override;
    virtual void dragLeaveEvent(QDragLeaveEvent *event) override;
    virtual void dragMoveEvent(QDragMoveEvent *event) override;
private:
    Ui::Widget *ui;
};
 

widget.cpp 檔案

#include "widget.h"
#include "ui_widget.h"
#include <QDragEnterEvent>
#include <QDragLeaveEvent>
#include <QDragMoveEvent>


Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
    this->setAcceptDrops(true);
    ui->textEdit->setAcceptDrops(false);

}

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

void Widget::dropEvent(QDropEvent *event)
{
    ui->textEdit->setText("QDropEvent");

}

void Widget::dragEnterEvent(QDragEnterEvent *event)
{
    ui->textEdit->setText("QDragEnterEvent");
    //傳遞事件
    event->acceptProposedAction();
}

void Widget::dragLeaveEvent(QDragLeaveEvent *event)
{
    ui->textEdit->setText("QDragLeaveEvent");
}

void Widget::dragMoveEvent(QDragMoveEvent *event)
{
    ui->textEdit->setText("QDragMoveEvent");
    //通過設定Qt::DrogAction 可以修改拖動過程中預設顯示的Copy
    /*
        enum DropAction {
        CopyAction = 0x1,
        MoveAction = 0x2,
        LinkAction = 0x4,
        ActionMask = 0xff,
        TargetMoveAction = 0x8002,
        IgnoreAction = 0x0
    };
    */
    event->setDropAction(Qt::MoveAction);
}