JTableHeader的工具提示未顯示其列的寬度

Question

我正在嘗試使我的JTableHeader的工具提示顯示它所屬的列的寬度，但它不起作用。工具提示未顯示。

這裏是我的JTableHeader：

myTable.setModel(new DefaultTableModel(new Object[][] {{ label1, label2, label3, label4} }, 
new String[] { "foo", "bar", "foo bar", "bar foo" })); 

final JTableHeader header = new TableHeaderTooltipWidth(myTable.getColumnModel()); 
header.setReorderingAllowed(false); 
header.setResizingAllowed(true); 

TableHeaderTooltipWidth是JTableHeader一個子類，我覆蓋的方法public String getToolTipText(MouseEvent e)，看完後Official Tutorial How to use Tool tips。

package gui.paneles.elementos; 

import java.awt.event.MouseEvent; 

import javax.swing.table.JTableHeader; 
import javax.swing.table.TableColumnModel; 

public class TableHeaderTooltipWidth extends JTableHeader { 

private static final long serialVersionUID = 1L; 

public TableHeaderTooltipWidth() { 

} 
public TableHeaderTooltipWidth(TableColumnModel model) { 
    super(); 
} 

    @Override 
    public String getToolTipText(MouseEvent e) { 
     int col = columnAtPoint(e.getPoint()); 
     return String.valueOf(this.getColumnModel().getColumn(col).getPreferredWidth()); 
    } 
} 

但是工具提示沒有顯示。任何幫助，將不勝感激。謝謝！

Answer 1

...閱讀官方教程如何使用工具提示後。

還檢查了：Specifying Tool Tips for Column Headers - How to Use Tables (The Java™ Tutorials > Creating a GUI With JFC/Swing > Using Swing Components)

import java.awt.*; 
import java.awt.event.*; 
import javax.swing.*; 
import javax.swing.table.*; 

public class TableHeaderTooltipWidthTest { 
    public JComponent makeUI() { 
    TableModel model = new DefaultTableModel(
     new Object[][] {{ "label1", "label2", "label3", "label4"} }, 
     new String[] { "foo", "bar", "foo bar", "bar foo" }); 
    // How to Use Tables (The Java™ Tutorials) 
    // Specifying Tool Tips for Column Headers 
    // https://docs.oracle.com/javase/tutorial/uiswing/components/table.html#headertooltip 
    JTable table = new JTable(model) { 
     //Implement table header tool tips. 
     @Override protected JTableHeader createDefaultTableHeader() { 
     return new JTableHeader(columnModel) { 
      @Override public String getToolTipText(MouseEvent e) { 
      int col = columnAtPoint(e.getPoint()); 
      return String.valueOf(getColumnModel().getColumn(col).getPreferredWidth()); 
      //int index = columnModel.getColumnIndexAtX(e.getPoint().x); 
      //int realIndex = columnModel.getColumn(index).getModelIndex(); 
      //return String.valueOf(columnModel.getColumn(realIndex).getPreferredWidth()); 
      } 
     }; 
     } 
    }; 
    return new JScrollPane(table); 
    } 
    public static void main(String... args) { 
    EventQueue.invokeLater(() -> { 
     JFrame f = new JFrame(); 
     f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE); 
     f.getContentPane().add(new TableHeaderTooltipWidthTest().makeUI()); 
     f.setSize(320, 240); 
     f.setLocationRelativeTo(null); 
     f.setVisible(true); 
    }); 
    } 
} 

Answer 2

你需要使用鼠標協調和計算出鼠標的位置根據你的表頭需要一個良好的數學方程式做