QSortFilterProxyModel简介及小例

QSortFilterProxyModel简介及小例

直接派生QAbstractProxyModel的子类方法足够灵活，但是需要实现两个数据集索引的映射，

并需要重载多个接口函数。如果这种映射只是对源模型中的数据项进行过滤或排序，可以使用Qt提供的

QSortFilterProxyModel.

在实现索引之间的映射时，该类考虑了过滤排序两种操作。关于过滤操作：成员函数setFilterKeyColumn(),

setFilterRegExp().关于排序，它重载了QAbstractItemModel的接口函数sort(),视图对象自动调用.

实例可参看Qt提供的demo,eg(mine):

C:\Qt\Qt5.3.2\Examples\Qt-5.3\widgets\itemviews\customsortfiltermodel

/****************************************************************************************************/

//colornamesdialog.h

#ifndef COLORNAMESDIALOG_H

#define COLORNAMESDIALOG_H

#include <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_H

//colornamesdialog.cpp

#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);  //设置源模型

proxyModel->setFilterKeyColumn(0);  //设置应用过滤的列

listView = new QListView;

listView->setModel(proxyModel);  //视图设置模型

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("RegExp: ",QRegExp::RegExp);    //0

syntaxComboBox->addItem("Wildcard: ",QRegExp::Wildcard);  //1

syntaxComboBox->addItem("Fixed string",QRegExp::FixedString); //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()));

}

void ColorNamesDialog::reapplyFilter(){

QRegExp::PatternSyntax syntax =

QRegExp::PatternSyntax(syntaxComboBox->currentIndex());

QRegExp regExp(filterLineEdit->text(),Qt::CaseInsensitive,syntax);

proxyModel->setFilterRegExp(regExp);

}

ColorNamesDialog::~ColorNamesDialog()

{

}

//main.cpp

#include "colornamesdialog.h"

#include <QApplication>

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

{

QApplication a(argc, argv);

ColorNamesDialog dialog;

dialog.setWindowTitle("My QSortFilterProxyModel Demo");

dialog.show();

return a.exec();

}

运行结果：