启动时swing Java Jtable行颜色
用java做一个库系统项目,我得到了根据字符串改变颜色的行,但是它们只在字符串改变时改变,并且在启动时没有检测到正确的字符串
以下是单击我的jMenu项以显示书籍时的代码:
public void displayBooks() {
// headers for the table
String[] columns = new String[] { "ISBN", "Title", "Author", "Publisher", "Pub Date", "Status" };
Object[][] data = new Object[booksList.size()][6];
for (int i = 0; i < booksList.size(); i++) {
Book book = booksList.get(i);
data[i][0] = book.getIsbn();
data[i][1] = book.getTitle();
data[i][2] = book.getAuthor();
data[i][3] = book.getPublisher();
data[i][4] = book.getPudDate();
data[i][5] = book.getStatus();
System.out.println(book.getStatus());
}
table = new JTable(data, columns);
table.setDefaultRenderer(Object.class, new MyCellRenderer());
this.getContentPane().removeAll();
TableColumn tableStatus = table.getColumnModel().getColumn(5);
JComboBox<String> comboBox = new JComboBox<String>();
comboBox.addItem("Available");
comboBox.addItem("Unavailable");
tableStatus.setCellEditor(new DefaultCellEditor(comboBox));
this.getContentPane().add(new JScrollPane(table));
this.revalidate();
}
现在是我的手机渲染器:
public class MyCellRenderer extends javax.swing.table.DefaultTableCellRenderer {
public java.awt.Component getTableCellRendererComponent(javax.swing.JTable table, java.lang.Object value,
boolean isSelected, boolean hasFocus, int row, int column)
{
final java.awt.Component cellComponent = super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
Object rowValue = table.getValueAt(row, 5);
Object[][] data = new Object[booksList.size()][6];
for (int i = 0; i < booksList.size(); i++) {
Book book = booksList.get(i);
data[i][0] = book.getIsbn();
data[i][1] = book.getTitle();
data[i][2] = book.getAuthor();
data[i][3] = book.getPublisher();
data[i][4] = book.getPudDate();
data[i][5] = book.getStatus();
System.out.println(book.getStatus());
if (rowValue == "Unavailable"){
cellComponent.setForeground(Color.BLACK);
cellComponent.setBackground(Color.red);;
}
else{
cellComponent.setBackground(Color.white);
cellComponent.setForeground(Color.black);
}
if(isSelected){
cellComponent.setForeground(table.getSelectionForeground());
cellComponent.setBackground(table.getSelectionBackground());
}
}
return cellComponent;
}
}
因此,要进行汇总,最后一行中“不可用”的行确实会变为红色,但只有在表加载后(而不是加载时)才变为红色
任何想法。谢谢。:)
# 1 楼答案
首先,不要使用“==”进行字符串比较。相反,您应该使用
String.equals(...)
方法:接下来,渲染器代码完全错误。渲染器一次渲染单个单元格。因此,如果您有5行数据,渲染器将被调用30次,因为您有6列数据
我建议您在论坛中搜索扩展
DefaultTableCellRenderer
的其他示例,然后修改这些示例但是,创建自定义渲染器的一个问题是,需要为表中的每种数据类型创建自定义渲染器。例如,“日期”通常由自定义日期渲染器而不是字符串渲染器渲染,因此可以合理地格式化数据
因此,与创建多个渲染器不同,您可能希望查看Table Row Rendering,它提供了一种替代解决方案