用qt c++写一个带ui界面继承qwidget的类，类名为TreeWidgetItemDrag，ui界面有两个treewidget，treewidget为横向的表格，实现两个表格能互相拖动qtreewidgetitem到对方表格中，同时移除自己表格中拖动的treewidgetitem

好的，以下是一个简单的实现：

TreeWidgetItemDrag.h

#ifndef TREEWIDGETITEMDRAG_H
#define TREEWIDGETITEMDRAG_H

#include <QWidget>
#include <QTreeWidget>

namespace Ui {
class TreeWidgetItemDrag;
}

class TreeWidgetItemDrag : public QWidget
{
    Q_OBJECT

public:
    explicit TreeWidgetItemDrag(QWidget *parent = nullptr);
    ~TreeWidgetItemDrag();

private:
    Ui::TreeWidgetItemDrag *ui;

    void setupTreeWidget(QTreeWidget *treeWidget);

private slots:
    void on_treeWidget_1_itemDragged(QTreeWidgetItem *item);
    void on_treeWidget_2_itemDragged(QTreeWidgetItem *item);
};

#endif // TREEWIDGETITEMDRAG_H

TreeWidgetItemDrag.cpp

#include "TreeWidgetItemDrag.h"
#include "ui_Treewidgetitemdrag.h"

#include <QDebug>

TreeWidgetItemDrag::TreeWidgetItemDrag(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::TreeWidgetItemDrag)
{
    ui->setupUi(this);

    setupTreeWidget(ui->treeWidget_1);
    setupTreeWidget(ui->treeWidget_2);
}

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

void TreeWidgetItemDrag::setupTreeWidget(QTreeWidget *treeWidget)
{
    // 设置treewidget为横向的表格
    treeWidget->setColumnCount(3);
    treeWidget->setHeaderLabels(QStringList() << "Column 1" << "Column 2" << "Column 3");

    // 允许treewidget的items拖动
    treeWidget->setDragEnabled(true);

    // 设置treewidget接受拖放事件
    treeWidget->setAcceptDrops(true);

    // 设置treewidget在拖动item时，显示的内容
    treeWidget->setDragDropMode(QAbstractItemView::DragDrop);

    // 设置treewidget在释放item时，移动item
    treeWidget->setDefaultDropAction(Qt::MoveAction);

    // 设置treewidget的items不能被编辑
    treeWidget->setEditTriggers(QAbstractItemView::NoEditTriggers);

    // 允许treewidget的items在内部移动
    treeWidget->setMovement(QTreeWidget::InternalMove);
}

void TreeWidgetItemDrag::on_treeWidget_1_itemDragged(QTreeWidgetItem *item)
{
    ui->treeWidget_1->takeTopLevelItem(ui->treeWidget_1->indexOfTopLevelItem(item));
    ui->treeWidget_2->addTopLevelItem(item);
}

void TreeWidgetItemDrag::on_treeWidget_2_itemDragged(QTreeWidgetItem *item)
{
    ui->treeWidget_2->takeTopLevelItem(ui->treeWidget_2->indexOfTopLevelItem(item));
    ui->treeWidget_1->addTopLevelItem(item);
}

其中ui界面可以使用Qt Designer进行设计，也可以手写代码。这里使用Qt Designer设计的ui文件为：

TreeWidgetItemDrag.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>TreeWidgetItemDrag</class>
 <widget class="QWidget" name="TreeWidgetItemDrag">
  <property name="windowTitle">
   <string>Tree Widget Item Drag</string>
  </property>
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>400</width>
    <height>300</height>
   </rect>
  </property>
  <layout class="QVBoxLayout" name="verticalLayout">
   <item>
    <widget class="QLabel" name="label">
     <property name="text">
      <string>Drag and drop items between two tree widgets:</string>
     </property>
    </widget>
   </item>
   <item>
    <widget class="QSplitter" name="splitter">
     <property name="orientation">
      <enum>Qt::Horizontal</enum>
     </property>
     <widget class="QTreeWidget" name="treeWidget_1">
      <property name="maximumWidth">
       <number>16777215</number>
      </property>
     </widget>
     <widget class="QTreeWidget" name="treeWidget_2">
      <property name="maximumWidth">
       <number>16777215</number>
      </property>
     </widget>
    </widget>
   </item>
  </layout>
 </widget>
 <resources/>
 <connections/>
</ui>

在主窗口中，只需要实例化TreeWidgetItemDrag类并将其添加到主窗口中即可：

MainWindow.cpp

#include "MainWindow.h"
#include "ui_MainWindow.h"

#include "TreeWidgetItemDrag.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    // 实例化TreeWidgetItemDrag类并将其添加到主窗口中
    ui->centralWidget->layout()->addWidget(new TreeWidgetItemDrag(this));
}

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

这样，就可以实现两个treewidget之间的拖动了。