QT：在QTableView中使用各种自定义委托

    QT的MVC（View/Delegate）模型十分强大，可以利用各种控件来对表格的输入进行限制，不过我以前一直没有过，这几天研究了一下，写个小例子，希望大家喜欢。

    如果看不懂这个例子，请先看QT的自带例子：http://qt-project.org/doc/qt-4.8/itemviews-spinboxdelegate.html

思路：

1：为每一列定义委托：
A：第一列是编号列，使用只读委托，令该列的单元格是只读的
B：第三列是ID列，只能输入1－12个数字，利用QLineEdit委托和正则表达式对输入进行限制
C：第四年龄列，利用QSpinBox委托进行输入限制，只能输入1－100之间的数字
D：第五列是性别列，利用QComboBox委托对输入进行限制，该列的单元格只能输入Male或Female
E：第六列是头像列，在该列的单元格中央放置一张头像

2：定义代理类，把所有单元格中的字符居中显示。

3：利用QSS，将表格的背景色弄成黄蓝相间。

截图：

上代码：

#include 

//编号列，只读委托
//这个方法我还真想不到，呵呵
class ReadOnlyDelegate : public QItemDelegate
{
	Q_OBJECT
public:
	ReadOnlyDelegate(QObject *parent = 0): QItemDelegate(parent) { }
	QWidget *createEditor(QWidget*parent, const QStyleOptionViewItem &option,
		const QModelIndex &index) const
	{
		return NULL;
	}
};

//ID列，只能输入1－12个数字
//利用QLineEdit委托和正则表达式对输入进行限制
class UserIDDelegate : public QItemDelegate
{
	Q_OBJECT
public:
	UserIDDelegate(QObject *parent = 0): QItemDelegate(parent) { }
	QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option,
		const QModelIndex &index) const
	{
		QLineEdit *editor = new QLineEdit(parent);
		QRegExp regExp("[0-9]{0,10}");
		editor->setValidator(new QRegExpValidator(regExp, parent));
		return editor;
	}
	void setEditorData(QWidget *editor, const QModelIndex &index) const
	{
		QString text = index.model()->data(index, Qt::EditRole).toString();
		QLineEdit *lineEdit = static_cast(editor);
		lineEdit->setText(text);
	}
	void setModelData(QWidget *editor, QAbstractItemModel *model,
		const QModelIndex &index) const
	{
		QLineEdit *lineEdit = static_cast(editor);
		QString text = lineEdit->text();
		model->setData(index, text, Qt::EditRole);
	}
	void updateEditorGeometry(QWidget *editor,
		const QStyleOptionViewItem &option, const QModelIndex &index) const
	{
		editor->setGeometry(option.rect);
	}
};

//年龄列，利用QSpinBox委托进行输入限制，只能输入1－100之间的数字
class AgeDelegate : public QItemDelegate
{
	Q_OBJECT
public:
	AgeDelegate(QObject *parent = 0): QItemDelegate(parent) { }
	QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option,
		const QModelIndex &index) const
	{
		QSpinBox *editor = new QSpinBox(parent);
		editor->setMinimum(1);
		editor->setMaximum(100);
		return editor;
	}
	void setEditorData(QWidget *editor, const QModelIndex &index) const
	{
		int value = index.model()->data(index, Qt::EditRole).toInt();
		QSpinBox *spinBox = static_cast(editor);
		spinBox->setValue(value);
	}
	void setModelData(QWidget *editor, QAbstractItemModel *model,
		const QModelIndex &index) const
	{
		QSpinBox *spinBox = static_cast(editor);
		spinBox->interpretText();
		int value = spinBox->value();
		model->setData(index, value, Qt::EditRole);
	}
	void updateEditorGeometry(QWidget *editor,
		const QStyleOptionViewItem &option, const QModelIndex &index) const
	{
		editor->setGeometry(option.rect);
	}
};

//性别列，利用QComboBox委托对输入进行限制
//这一列的单元格只能输入Male或Female
class SexDelegate : public QItemDelegate
{
	Q_OBJECT
public:
	SexDelegate(QObject *parent = 0): QItemDelegate(parent) { }
	QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option,
		const QModelIndex &index) const
	{
		QComboBox *editor = new QComboBox(parent);
		editor->addItem("Female");
		editor->addItem("Male");
		return editor;
	}
	void setEditorData(QWidget *editor, const QModelIndex &index) const
	{
		QString text = index.model()->data(index, Qt::EditRole).toString();
		QComboBox *comboBox = static_cast(editor);
		int tindex = comboBox->findText(text);
		comboBox->setCurrentIndex(tindex);
	}
	void setModelData(QWidget *editor, QAbstractItemModel *model,
		const QModelIndex &index) const
	{
		QComboBox *comboBox = static_cast(editor);
		QString text = comboBox->currentText();
		model->setData(index, text, Qt::EditRole);
	}
	void updateEditorGeometry(QWidget *editor,
		const QStyleOptionViewItem &option, const QModelIndex &index) const
	{
		editor->setGeometry(option.rect);
	}
};

//头像列，只是在单元格中央放一张小图而已
class IconDelegate : public QItemDelegate
{
	Q_OBJECT
public:
	IconDelegate(QObject *parent = 0): QItemDelegate(parent) { }
	void paint(QPainter *painter, const QStyleOptionViewItem &option,
		const QModelIndex & index ) const
	{
		//show.bmp是在工程目录中的一张图片（其实就是QQ的图标啦，呵呵）
		QPixmap pixmap = QPixmap("show.bmp").scaled(24, 24);
		qApp->style()->drawItemPixmap(painter, option.rect,  Qt::AlignCenter, QPixmap(pixmap));
	}
};

//代理类，把所有单元格中的字符居中显示
class VIPModel : public QStandardItemModel
{
	Q_OBJECT
public:
	VIPModel(QObject *parent=NULL) : QStandardItemModel(parent) { }
	VIPModel(int row, int column, QObject *parent=NULL)
		: QStandardItemModel(row, column, parent) { }
	QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const
	{
		if( Qt::TextAlignmentRole == role )
			return Qt::AlignCenter; 
		return QStandardItemModel::data(index, role);
	}

};

#include "main.moc"

int main(int argc, char *argv[])
{
	QApplication app(argc, argv);

	VIPModel *model = new VIPModel(5, 5);
	QTableView *tableView = new QTableView;

	//把表格的背景调成黄蓝相间
	//这种方法是在网上看到的，用起来还真方便啊
	tableView->setAlternatingRowColors(true);
	tableView->setStyleSheet("QTableView{background-color: rgb(250, 250, 115);"
		"alternate-background-color: rgb(141, 163, 215);}");

	tableView->setWindowTitle("VIP List");
	tableView->resize(700, 400);
	tableView->setModel(model);
	QStringList headerList;
	headerList << "No." << "ID" << "Name" << "Age" << "Sex" << "Show";
	model->setHorizontalHeaderLabels(headerList);
	tableView->verticalHeader()->setVisible(false);
	tableView->horizontalHeader()->setStretchLastSection(true);

	//为每一列加载委托
	ReadOnlyDelegate readOnlyDelegate;
	tableView->setItemDelegateForColumn(0, &readOnlyDelegate);
	UserIDDelegate userIDDelegate;
	tableView->setItemDelegateForColumn(1, &userIDDelegate);
	AgeDelegate spinBoxDelegate;
	tableView->setItemDelegateForColumn(3, &spinBoxDelegate);
	SexDelegate comboBoxDelegate;
	tableView->setItemDelegateForColumn(4, &comboBoxDelegate);
	IconDelegate iconDelegate;
	tableView->setItemDelegateForColumn(5, &iconDelegate);

	for(int i=0; i<10; i++)
	{
		QModelIndex index = model->index(i, 0, QModelIndex());
		model->setData(index, i);
	}

	tableView->show();
	return app.exec();
}