qt dragEnterEvent dragLeaveEvent dragMoveEvent dropEvent都不响应的问题解决方案。

环境：vs2019+qt5.14.2

坑哦。让我搞了好久。各种不执行，最后发现,不用vs调制，直接运行exe就能接收拖拽了。

记录一下,感觉是qt的bug。上代码。

#ifndef MAINWINDOW_H
#define MAINWINDOW_H#include <QMainWindow>
#include <QTextEdit>class MainWindow : public QMainWindow
{Q_OBJECTpublic:explicit MainWindow(QWidget* parent = 0);~MainWindow();protected:void dragEnterEvent(QDragEnterEvent* e) override;void dragLeaveEvent(QDragLeaveEvent* e) override;void dragMoveEvent(QDragMoveEvent* event) override;void dropEvent(QDropEvent* e) override;private:bool readFile(const QString& fileName);QTextEdit* textEdit;
};#endif // MAINWINDOW_H

#include <QDragEnterEvent>
#include <QMimeData>
#include <QFile>
#include <QUrl>
#include <QDebug>
#include "QtWidgetsApplication5.h"MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent)
{//this->setMouseTracking(true); 不加也行textEdit = new QTextEdit;setCentralWidget(textEdit);textEdit->setAcceptDrops(false); setAcceptDrops(true);setWindowTitle(tr("Text Editor"));
}MainWindow::~MainWindow()
{}void MainWindow::dragEnterEvent(QDragEnterEvent* e)
{qDebug() << "dragEnterEvent" << e->mimeData();e->accept();if (e->mimeData()->hasFormat("text/uri-list"))e->acceptProposedAction(); 
}void MainWindow::dragLeaveEvent(QDragLeaveEvent* e)
{qDebug() << "dragLeaveEvent";//e->accept();  不加也行
}void MainWindow::dragMoveEvent(QDragMoveEvent* event)
{event->setDropAction(Qt::MoveAction);//event->accept(); 不加也行
}void MainWindow::dropEvent(QDropEvent* e) //释放对方时，执行的操作
{//e->accept(); 不加也行QList<QUrl> urls = e->mimeData()->urls();if (urls.isEmpty())return;QString fileName = urls.first().toLocalFile();foreach(QUrl u, urls) {qDebug() << u.toString();}qDebug() << urls.size();if (fileName.isEmpty())return;if (readFile(fileName))setWindowTitle(tr("%1 - %2").arg(fileName).arg("Drag File"));
}bool MainWindow::readFile(const QString& fileName) //读文件
{QFile file(fileName);if (!file.open(QFile::ReadOnly | QFile::Text))return false;QByteArray data;data = file.readAll();textEdit->setText(QString::fromLocal8Bit(data));return true;
}

#include "QtWidgetsApplication5.h"
#include <QtWidgets/QApplication>int main(int argc, char *argv[])
{QApplication a(argc, argv);MainWindow w;w.show();return a.exec();
}

运行结果：