QSqlTableModel的用法

本文介绍了一种SQL模型类-QSqlTableModel的使用方法及特点, QSqlTableModel是Qt框架中用于操作数据库的重要组件, 可以帮助开发者更方便地进行数据表的操作与管理。

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使用 AbstractTableModel 构建Table 在表格中添加JButton按钮,之前在网上找了2天没有找到好用的程序,最终终于找到一个好用的例子。 不要使,我退你们分。。 sing the Swing JTable class can quickly become a sticky business when you want to customize it to your specific needs. First you must become familiar with how the JTable class is organized. Individual cells are rendered by TableCellRenderer implementations. The table contents are represented by an implementation of the TableModel interface. By default, JTable uses DefaultTableCellRenderer to draw its cells. DefaultTableCellRenderer recognizes a few primitive types, rendering them as strings, and can even display Boolean types as checkboxes. But it defaults to displaying the value returned by toString() for types it does not specifically handle. You have to provide your own TableCellRenderer implementation if you want to display buttons in a JTable. The TableCellRenderer interface contains only one method, getTableCellRendererComponent(...), which returns a java.awt.Component that knows how to draw the contents of a specific cell. Usually, getTableCellRendererComponent() will return the same component for every cell of a column, to avoid the unnecessary use of extra memory. But when the contents of a cell is itself a component, it is all right to return that component as the renderer. Therefore, the first step towards having JButtons display correctly in a JTable is to create a TableCellRenderer implementation that returns the JButton contained in the cell being rendered. In the accompanying code listing, JTableButtonRenderer demonstrates how to do this. Even after creating a custom TableCellRenderer, you're still not done. The TableModel associated with a given JTable does not only keep track of the contents of each cell, but it also keeps track of the class of data stored in each column. DefaultTableModel is designed to work with DefaultTableCellRenderer and will return java.lang.String.class for columns containing data types that it does not specifically handle. The exact method that does this is getColumnClass(int column). Your second step is to create a TableModel implementation that returns JButton.class for cells that contain JButtons. JTableButtonModel shows one way to do this. It just returns the result of getClass() for each piece of cell data. At this point, you're almost done, but not quite. What's the use of putting a JButton in a JTable if you can't press the darn thing? By default, JTable will not forward mouse events to components contained in its cells. If you want to be able to press the buttons you add to JTable, you have to create your own MouseListener that forwards events to the JButton cells. JTableButtonMouseListener demonstrates how you could do this.
QSqlTableModel是一个用于访问数据库表中数据的Qt数据模型。它可以与SQL数据库表交互,让我们可以对表进行增、删、改、查等操作。 以下是一个简单的使用QSqlTableModel的例子: ```cpp #include <QtSql> int main(int argc, char *argv[]) { QApplication a(argc, argv); // 创建一个QSqlDatabase对象 QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE"); db.setDatabaseName("test.db"); // 打开数据库 if (!db.open()) { qDebug() << "Failed to open database!"; return 1; } // 创建一个QSqlTableModel对象 QSqlTableModel model; model.setTable("students"); // 设置表名 model.setEditStrategy(QSqlTableModel::OnManualSubmit); // 设置提交策略 // 选择需要显示的列 model.select(); model.setHeaderData(0, Qt::Horizontal, tr("ID")); model.setHeaderData(1, Qt::Horizontal, tr("Name")); model.setHeaderData(2, Qt::Horizontal, tr("Age")); // 创建一个QTableView对象,并将QSqlTableModel作为其数据源 QTableView *view = new QTableView; view->setModel(&model); view->show(); return a.exec(); } ``` 在这个例子中,我们使用了QSqlTableModel来访问数据库中的"students"表,并在QTableView中显示了该表的内容。通过设置setTable()方法,我们指定了表名,设置setEditStrategy()方法来指定提交策略,使用select()方法选择需要显示的列,并使用setHeaderData()方法设置列标题。最后,我们创建了一个QTableView对象,并将QSqlTableModel作为其数据源。
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