浅谈Qt代理

当我们使用QTableView 显示一张表时， 在表格输入时， 比如输入日期时， 我们可能想一个可以选择日期的日历表， 选择职业时， 可能想有一个可以提供下拉的combox提供选择，这时， 就需要用到代理。 

直接上源码：

#include "combodelegate.h"

#include <QComboBox>

ComboDelegate::ComboDelegate(QObject *parent) :

    QItemDelegate(parent)

{

}

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

{

    QStringList list;

    list << "工人" << "农民" << "军人" << "律师";

    QComboBox *editor = new QComboBox(parent);

    editor->addItems(list);

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

    return editor;

}

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

{

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

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

    int i = box->findText(dateStr);

    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);

}

#include "widget.h"

#include <QApplication>

#include <QStandardItemModel>

#include <QTableView>

#include <QFile>

#include <QTextStream>

#include <QDebug>

#include "datedelegate.h"

#include "combodelegate.h"

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

{

    QApplication a(argc, argv);

    /*

    Widget w;

    w.show();

    */

    QStandardItemModel model(4, 4);

    QTableView tableView;

    tableView.setModel(&model);

    model.setHeaderData(0, Qt::Horizontal, QLatin1String("Name"));

    model.setHeaderData(1, Qt::Horizontal, QLatin1String("Birthday"));

    model.setHeaderData(2, Qt::Horizontal, QLatin1String("Job"));

    model.setHeaderData(3, Qt::Horizontal, QLatin1String("Income"));

    QFile file(QLatin1String("D:/test.txt"));

    if(!file.open(QIODevice::ReadOnly | QIODevice::Text)) {

        qDebug() << "pen the file failed";

        return -1;

    }

    QTextStream out(&file);

    QString line;

    model.removeRows(0, model.rowCount(QModelIndex()), QModelIndex());

    int row = 0;

    do {

        line = out.readLine();

        if(!line.isEmpty()) {

            model.insertRows(row, 1, QModelIndex());

            QStringList pieces = line.split(",", QString::SkipEmptyParts);

            model.setData(model.index(row, 0, QModelIndex()), pieces.value(0));

            model.setData(model.index(row, 1, QModelIndex()), pieces.value(1));

            model.setData(model.index(row, 2, QModelIndex()), pieces.value(2));

            model.setData(model.index(row, 3, QModelIndex()), pieces.value(3));

            row++;

        }

    } while(!line.isEmpty());

    file.close();

    tableView.setWindowTitle(QLatin1String("Delegate"));

    DateDelegate dateDelegate;

    tableView.setItemDelegateForColumn(1, &dateDelegate);

    ComboDelegate comboDelegate;

    tableView.setItemDelegateForColumn(2, &comboDelegate);

    tableView.show();

    return a.exec();

}

这是自己手动输入的数据。

最后运行的效果如下 图：