一、概述

功能:?實現一個查詢學生信息的表格，有學號、性別、年齡、班級和分數共5列，針對最后一列分數實現委托代理，要求能編輯和查看該分數列。

QTableView實現視圖展示ui

Model負責數據的構造

Delegate是委托，可針對某列數據做自定義擴展

使用的qt控件如下：

• QTableView
• StudentTableModel繼承自QAbstractTableModel
• ScoreDelegate繼承自QStyledItemDelegate

二、具體代碼

studenttablemodel.h

#ifndef STUDENTTABLEMODEL_H
#define STUDENTTABLEMODEL_H#include <QAbstractTableModel>
#include <QObject>class StudentTableModel : public QAbstractTableModel
{Q_OBJECT
public:explicit StudentTableModel(QObject *parent = nullptr);int rowCount(const QModelIndex &parent = QModelIndex()) const override;int columnCount(const QModelIndex &parent = QModelIndex()) const override;QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;QVariant headerData(int section, Qt::Orientation orientation,int role = Qt::DisplayRole) const override;bool setData(const QModelIndex &index, const QVariant &value, int role = Qt::EditRole) override;Qt::ItemFlags flags(const QModelIndex &index) const override;private:QVector<QVector<QVariant>> m_data; // 數據存儲
};#endif // STUDENTTABLEMODEL_H

studenttablemodel.cpp

#include "studenttablemodel.h"StudentTableModel::StudentTableModel(QObject *parent): QAbstractTableModel{parent}
{// 初始化示例數據m_data = {{"1001", "male", 18, "class_01", 85},{"1002", "female", 19, "class_02", 92},{"1003", "male", 20, "class_03", 78}};
}int StudentTableModel::rowCount(const QModelIndex &parent) const
{Q_UNUSED(parent);return m_data.size();
}int StudentTableModel::columnCount(const QModelIndex &parent) const
{Q_UNUSED(parent);return 5; // 學號、性別、年齡、班級、分數
}QVariant StudentTableModel::data(const QModelIndex &index, int role) const
{if(!index.isValid()) return QVariant();if (role == Qt::DisplayRole || role == Qt::EditRole) {return m_data[index.row()][index.column()];}return QVariant();
}QVariant StudentTableModel::headerData(int section, Qt::Orientation orientation, int role) const
{if (role == Qt::DisplayRole && orientation == Qt::Horizontal) {switch (section) {case 0: return "id";case 1: return "sex";case 2: return "age";case 3: return "class";case 4: return "score";}}return QVariant();
}bool StudentTableModel::setData(const QModelIndex &index, const QVariant &value, int role)
{if (role == Qt::EditRole && index.isValid()) {m_data[index.row()][index.column()] = value;emit dataChanged(index, index); // 通知視圖更新return true;}return false;
}Qt::ItemFlags StudentTableModel::flags(const QModelIndex &index) const
{auto flags = QAbstractTableModel::flags(index);if (index.column() == 4) // 分數列可編輯flags |= Qt::ItemIsEditable;return flags;
}

scoredelegate.h

#ifndef SCOREDELEGATE_H
#define SCOREDELEGATE_H#include <QObject>
#include <QStyledItemDelegate>class ScoreDelegate : public QStyledItemDelegate
{Q_OBJECT
public:explicit ScoreDelegate(QObject *parent = nullptr);QWidget *createEditor(QWidget *parent,const QStyleOptionViewItem &option,const QModelIndex &index) const override;void setEditorData(QWidget *editor, const QModelIndex &index) const override;void setModelData(QWidget *editor,QAbstractItemModel *model,const QModelIndex &index) const override;
};#endif // SCOREDELEGATE_H

#include "scoredelegate.h"#include <QSpinBox>ScoreDelegate::ScoreDelegate(QObject *parent): QStyledItemDelegate{parent}
{}QWidget *ScoreDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const
{if (index.column() == 4) { // 僅對分數列生效QSpinBox *editor = new QSpinBox(parent);editor->setRange(0, 100);editor->setFrame(false);return editor;}return QStyledItemDelegate::createEditor(parent, option, index);
}void ScoreDelegate::setEditorData(QWidget *editor, const QModelIndex &index) const
{if (index.column() == 4) {int value = index.model()->data(index, Qt::EditRole).toInt();QSpinBox *spinBox = qobject_cast<QSpinBox*>(editor);spinBox->setValue(value);} else {QStyledItemDelegate::setEditorData(editor, index);}
}void ScoreDelegate::setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const
{if (index.column() == 4) {QSpinBox *spinBox = qobject_cast<QSpinBox*>(editor);spinBox->interpretText();model->setData(index, spinBox->value());} else {QStyledItemDelegate::setModelData(editor, model, index);}
}

widget.cpp

Widget::Widget(QWidget *parent): QWidget(parent), ui(new Ui::Widget)
{ui->setupUi(this);model = new StudentTableModel(this);scoreDelegate = new ScoreDelegate(this);ui->tableView->setModel(this->model);ui->tableView->setItemDelegateForColumn(4, scoreDelegate);// 表格樣式設置ui->tableView->verticalHeader()->hide();ui->tableView->horizontalHeader()->setSectionResizeMode(QHeaderView::Stretch);ui->tableView->setEditTriggers(QAbstractItemView::DoubleClicked | QAbstractItemView::SelectedClicked);//手動設置show顯示ui->tableView->show();
}

三、遇到問題總結

1、QTableView展示不出來，model+tableview為局部變量

?當構造函數執行結束時，這兩個對象會被自動銷毀。即使調用了?tableView.show()，窗口會短暫顯示，但對象銷毀后視圖也隨之消失，因此實際看不到表格

? ? 解決方案?：
將?tableView?和?model??提升為類的成員變量，確保其生命周期與窗口一致：

2、??視圖未嵌入父窗口布局

問題分析?：

• 即使解決了生命周期問題，若?tableView?未添加到窗口布局中，它可能因尺寸為0或位置錯誤而不可見。
• 你的代碼中?tableView?是獨立創建的，未關聯到?ui?生成的界面布局中。

?解決方案?：
將?tableView?添加到窗口的布局管理器中（例如使用?QVBoxLayout）：