Qt 代理

// 头文件.h

#ifndef SPINBOXDELEGATE_H

#define SPINBOXDELEGATE_H

#include <QItemDelegate>

#include <QObject>

#include <QStyledItemDelegate>

class SpinBoxDelegate : public QItemDelegate

{

    Q_OBJECT

public:

    SpinBoxDelegate(QObject* parent = 0);

    // editing

    QWidget *createEditor(QWidget *parent,

                          const QStyleOptionViewItem &option,

                          const QModelIndex &index) const override;

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

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

    void updateEditorGeometry(QWidget *editor,

                              const QStyleOptionViewItem &option,

                              const QModelIndex &index) const override;

};

class ComboBoxDelegate : public QItemDelegate

{

    Q_OBJECT

public:

    ComboBoxDelegate(QObject* parent = 0);

    // editing

    QWidget *createEditor(QWidget *parent,

                          const QStyleOptionViewItem &option,

                          const QModelIndex &index) const override;

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

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

    void updateEditorGeometry(QWidget *editor,

                              const QStyleOptionViewItem &option,

                              const QModelIndex &index) const override;

};

class ProgressBarDelegate : public QStyledItemDelegate

{

    Q_OBJECT

public:

    ProgressBarDelegate(QObject* parent);

protected:

    // painting

    void paint(QPainter *painter,

               const QStyleOptionViewItem &option, const QModelIndex &index) const override;

};

#endif // SPINBOXDELEGATE_H

// 源文件

#include "spinboxdelegate.h"

#include <QComboBox>

#include <QSpinBox>

#include <QApplication>

SpinBoxDelegate::SpinBoxDelegate(QObject* parent)

    :QItemDelegate (parent)

{

}

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

{

    QSpinBox * editor = new QSpinBox(parent);

    editor->setMinimum(0);

    editor->setMaximum(100);

    return editor;

}

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

{

    int value = index.model()->data(index, Qt::EditRole).toInt();

    auto * spinBox = static_cast<QSpinBox*>(editor);

    spinBox->setValue(value);

}

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

{

    auto* spinBox = static_cast<QSpinBox*>(editor);

    spinBox->interpretText();   // 刷新

    int value = spinBox->value();

    model->setData(index, value, Qt::EditRole);

}

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

{

    editor->setGeometry(option.rect);

}

///

ComboBoxDelegate::ComboBoxDelegate(QObject *parent)

{

}

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

{

    QComboBox* editor = new QComboBox(parent);

    editor->addItem("Student 1", 1);

    editor->addItem("Student 2", 2);

    return editor;

}

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

{

    int value = index.model()->data(index, Qt::EditRole).toInt() % 2;

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

    comboBox->setCurrentIndex(value);

}

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

{

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

    int value = comboBox->currentIndex();

    model->setData(index, value, Qt::EditRole);

}

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

{

    editor->setGeometry(option.rect);

}

///

ProgressBarDelegate::ProgressBarDelegate(QObject* parent)

{

}

// 绘制进度条

void ProgressBarDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const

{

    if (index.isValid() && index.column() == 1){

        QStyleOptionProgressBar bar;

        bar.rect = option.rect;

        bar.progress = index.data().toInt();

        bar.maximum = 100;

        bar.minimum = 0;

        bar.text = QString::number(bar.progress) + "%";

        bar.textVisible = true;

        QApplication::style()->drawControl(QStyle::CE_ProgressBar, &bar, painter);

    }else{

        QStyledItemDelegate::paint(painter, option, index);

    }

}

// 使用

#include "mainwindow.h"

#include "ui_mainwindow.h"

#include <QStandardItemModel>

#include <QTableView>

#include "spinboxdelegate.h"

#include <QTimer>

MainWindow::MainWindow(QWidget *parent) :

    QMainWindow(parent),

    ui(new Ui::MainWindow)

{

    ui->setupUi(this);

    auto* model = new QStandardItemModel(7, 4, this);

    for (int row = 0; row < 7; row++){

        for (int column = 0; column < 4; column++){

            QStandardItem* item = new QStandardItem(QString("%1").arg(row*4 + column));

            model->setItem(row, column, item);

        }

    }

    QTableView* _tableView = new QTableView;

    _tableView->setModel(model);

    setCentralWidget(_tableView);

    this->resize(800, 800);

    auto* model2 = new QStandardItemModel(7, 4, this);

    for (int row = 0; row < 7; row++){

        for (int column = 0; column < 4; column++){

            QStandardItem* item = new QStandardItem(QString("%1").arg(row*4 + column));

            model2->setItem(row, column, item);

        }

    }

    auto* delegate = new SpinBoxDelegate(this);

    _tableView2 = new QTableView();

    _tableView2->setModel(model2);

    _tableView2->setItemDelegateForColumn(0, delegate);

    auto* delegateCombo = new ComboBoxDelegate(this);

    _tableView2->setItemDelegateForColumn(3, delegateCombo);

    auto* progressBarDelegate = new ProgressBarDelegate(this);

    _tableView2->setItemDelegateForColumn(1, progressBarDelegate);

    _tableView2->show();

    _tableView2->resize(800, 800);

    timer = new QTimer();

    connect(timer, &QTimer::timeout, this, &MainWindow::slot_timeout);

    timer->setInterval(1000);

    timer->start();

}

MainWindow::~MainWindow()

{

    delete ui;

    delete _tableView2;

}

void MainWindow::slot_timeout()

{

}