#include "constantdiag.h"

 #include <QtWidgets/QApplication>

 int main(int argc, char *argv[])

 {

     QApplication a(argc, argv);

     constantDiag w;

     w.show();

     return a.exec();

 }

 #ifndef CONSTANTDIAG_H

 #define CONSTANTDIAG_H

 #include <QtWidgets/QWidget>

 #include <QHBoxLayout>

 #include <QPushButton>

 #include <QStandardItemModel>

 #include <QTableView>

 #include <QVBoxLayout>

 #include <QHeaderView>

 #include <QLabel>

 class ComboDelegate;

 class constantDiag : public QWidget

 {

     Q_OBJECT

 public:

     constantDiag(QWidget *parent = );

     ~constantDiag();

 public slots:

     void addConstant();

     void reduceConstant();

 private:

     QHBoxLayout *secondHLayout;

     QPushButton *btnConstantPlus;

     QPushButton *btnConstantMinus;

     QStandardItemModel *model;

     QTableView *tableview;

     QVBoxLayout *wholeLayout;

     QHBoxLayout *thirdHLayout;

     QPushButton *btnOk;

     QPushButton *btnCancel;

     QHBoxLayout *topLayout;

     QLabel *titleLabel;

     QVBoxLayout *wholeVLayout;

     ComboDelegate *comboDelegate;

 };

 #endif // CONSTANTDIAG_H

 #ifndef COMBODELEGATE_H

 #define COMBODELEGATE_H

 #include <QItemDelegate>

 class ComboDelegate : public QItemDelegate

 {

     Q_OBJECT

 public:

     ComboDelegate(QObject *parent = );

     QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex    &index) const;

     void setEditorData(QWidget *editor, const QModelIndex &index) const;

     void setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const;

     void updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option, const  QModelIndex &index) const;

 };

 #endif // COMBODELEGATE_H

 #include "constantdiag.h"

 constantDiag::constantDiag(QWidget *parent)

     : QWidget(parent)

 {

     setWindowTitle(QString::fromLocal8Bit("系统常量"));

     resize(,);

     wholeLayout = new QVBoxLayout(parent);

     secondHLayout = new QHBoxLayout();

     secondHLayout->addStretch();

     btnConstantPlus = new QPushButton;

     btnConstantPlus->setText("+");

     secondHLayout->addWidget(btnConstantPlus);

     btnConstantMinus = new QPushButton;

     btnConstantMinus->setText("-");

     secondHLayout->addWidget(btnConstantMinus);

     secondHLayout->setStretch(,);

     secondHLayout->setStretch(,);

     secondHLayout->setStretch(,);

     wholeLayout->addLayout(secondHLayout);

     model = new QStandardItemModel(,);

     model->setHeaderData(,Qt::Horizontal,QString::fromLocal8Bit("名称"));

     model->setHeaderData(,Qt::Horizontal,QString::fromLocal8Bit("值"));

     model->setHeaderData(,Qt::Horizontal,QString::fromLocal8Bit("单位"));

     tableview = new QTableView(parent);

     tableview->setModel(model);

     tableview->verticalHeader()->setVisible(false);

     tableview->horizontalHeader()->setSectionResizeMode(, QHeaderView::Stretch);

     tableview->horizontalHeader()->setSectionResizeMode(, QHeaderView::Stretch);

     tableview->horizontalHeader()->setSectionResizeMode(, QHeaderView::Stretch);

     comboDelegate = new ComboDelegate;

     tableview->setItemDelegateForColumn(,comboDelegate);

     //tableview->verticalHeader()->setSectionResizeMode(0,QHeaderView::Stretch);

     //tableview->verticalHeader()->setSectionResizeMode(1,QHeaderView::Stretch);

     wholeLayout->addWidget(tableview);

     thirdHLayout = new QHBoxLayout;

     thirdHLayout->addStretch();

     btnOk = new QPushButton;

     btnOk->setText(QString::fromLocal8Bit("确定"));

     btnCancel = new QPushButton;

     btnCancel->setText(QString::fromLocal8Bit("取消"));

     thirdHLayout->addWidget(btnOk);

     thirdHLayout->addWidget(btnCancel);

     thirdHLayout->setStretch(,);

     thirdHLayout->setStretch(,);

     thirdHLayout->setStretch(,);

     wholeLayout->addLayout(thirdHLayout);

     //wholeLayout->setSizeConstraint(QLayout::SetFixedSize);

     //wholeLayout->setStretchFactor(secondHLayout, 1);

     //wholeLayout->setStretchFactor(tableview, 2);

     //wholeLayout->setStretchFactor(thirdHLayout, 1);

     setLayout(wholeLayout);

     connect(btnConstantPlus,SIGNAL(clicked()),this,SLOT(addConstant()));

     connect(btnConstantMinus,SIGNAL(clicked()),this,SLOT(reduceConstant()));

 }

 constantDiag::~constantDiag()

 {

 }

 void constantDiag::addConstant()

 {

     int row = model->rowCount();

     model->insertRow(row);

 }

 void constantDiag::reduceConstant()

 {

     int row = model->rowCount();

     model->removeRow(--row);

 }

 #include <QComboBox>

 ComboDelegate::ComboDelegate(QObject *parent) :

 QItemDelegate(parent)

 {

 }

 QWidget *ComboDelegate::createEditor(QWidget *parent,const QStyleOptionViewItem &/*option*/,const QModelIndex &/*index*/) const

 {

     QComboBox *editor = new QComboBox(parent);

     //editor->lineEdit()->setAlignment(Qt::AlignCenter);

     editor->setEditable(true);

     //editor->setStyleSheet("QComboBox{border:1px solid gray;}""QComboBox QAbstractItemView::item{height:25px;}");

     //editor->setView(new QListView());

     editor->addItem("N");

     editor->addItem("m");

     editor->addItem("m/s");

     editor->installEventFilter(const_cast<ComboDelegate*>(this));

     return editor;

 }

 void ComboDelegate::setEditorData(QWidget *editor,const QModelIndex &index) const

 {

     QString str =index.model()->data(index).toString();

     QComboBox *box = static_cast<QComboBox*>(editor);

     int i=box->findText(str);

     box->setCurrentIndex(i);

 }

 void ComboDelegate::setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const

 {

     QComboBox *box = static_cast<QComboBox*>(editor);

     QString str = box->currentText();

     model->setData(index,str);

 }

 void ComboDelegate::updateEditorGeometry(QWidget *editor,const QStyleOptionViewItem &option, const QModelIndex &/*index*/) const

 {

     editor->setGeometry(option.rect);

 }