QSortFilterProxyModel的简单用法

　　参考<<C++ GUI Programming with Qt 4>>中文版第二版中的例子"ColorNamesDialog"，简单介绍QSortFilterProxyModel的用法，QSortFilterProxyModel不能单独使用，它只是一个“代理”，真正的数据需要另外的一个model提供，而且它是用来排序和过滤的。

　　colornamesdialog.h文件：

#ifndef COLORNAMESDIALOG_H
#define COLORNAMESDIALOG_H

#include <QtGui/QDialog>
#include <QSortFilterProxyModel>
#include <QStringListModel>
#include <QListView>
#include <QComboBox>
#include <QLineEdit>

class ColorNamesDialog : public QDialog
{
Q_OBJECT

public:
ColorNamesDialog(QWidget *parent = 0);
~ColorNamesDialog();
private slots:
void reapplyFilter();
private:
QSortFilterProxyModel *proxyModel;
QStringListModel *sourceModel;
QListView *listView;
QComboBox *syntaxComboBox;
QLineEdit *filterLineEdit;
};

#endif

　　colornamesdialog.cpp文件：

#include "colornamesdialog.h"
#include <QLabel>
#include <QHBoxLayout>
#include <QVBoxLayout>

ColorNamesDialog::ColorNamesDialog(QWidget *parent)
: QDialog(parent)
{
sourceModel = new QStringListModel(this);
sourceModel->setStringList(QColor::colorNames());

proxyModel = new QSortFilterProxyModel(this);
proxyModel->setSourceModel(sourceModel);
proxyModel->setFilterKeyColumn(0);

listView = new QListView;
listView->setModel(proxyModel);

QLabel *filterLabel = new QLabel("Filter:", this);
filterLabel->setFixedWidth(100);
QLabel *patternLabel = new QLabel("Pattern syntax:", this);
patternLabel->setFixedWidth(100);

filterLineEdit = new QLineEdit(this);
syntaxComboBox = new QComboBox(this);
syntaxComboBox->addItem("Regular expression", QRegExp::RegExp); // QRegExp::RegExp   为 0
syntaxComboBox->addItem("Wildcard", QRegExp::Wildcard);         // QRegExp::Wildcard 为 1
syntaxComboBox->addItem("Fixed string", QRegExp::Wildcard);     // QRegExp::Wildcard 为 2

QHBoxLayout *filterLayout = new QHBoxLayout;
filterLayout->addWidget(filterLabel);
filterLayout->addWidget(filterLineEdit);

QHBoxLayout *patternLayout = new QHBoxLayout;
patternLayout->addWidget(patternLabel);
patternLayout->addWidget(syntaxComboBox);

QVBoxLayout *mainLayout = new QVBoxLayout;
mainLayout->addWidget(listView);
mainLayout->addLayout(filterLayout);
mainLayout->addLayout(patternLayout);

setLayout(mainLayout);
connect(syntaxComboBox, SIGNAL(currentIndexChanged(int)), this, SLOT(reapplyFilter()));
connect(filterLineEdit, SIGNAL(textChanged(QString)), this, SLOT(reapplyFilter()));
}

ColorNamesDialog::~ColorNamesDialog()
{
}

void ColorNamesDialog::reapplyFilter()
{
QRegExp::PatternSyntax syntax = QRegExp::PatternSyntax(syntaxComboBox->itemData(
syntaxComboBox->currentIndex()).toInt());
QRegExp regExp(filterLineEdit->text(), Qt::CaseInsensitive, syntax);
proxyModel->setFilterRegExp(regExp);
}

　　main.cpp文件：

#include <QtGui/QApplication>
#include "colornamesdialog.h"

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
ColorNamesDialog w;
w.show();
w.setWindowTitle("QSortFilterProxyModel Demo");
return a.exec();
}

　　运行界面：