QSortFilterProxyModel的简单用法

最新推荐文章于 2025-05-20 14:52:32 发布

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最新推荐文章于 2025-05-20 14:52:32 发布

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本文通过ColorNamesDialog实例介绍了Qt中QSortFilterProxyModel的应用。该组件作为代理，依赖于其他模型提供数据，并实现数据的排序与过滤功能。文章展示了如何通过QLineEdit输入内容和QComboBox选择模式来更新视图。

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　　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();
}