Java中的列表框

Question

I was trying to build the Font window of Notepad using Java using the code shown below. But, I'm facing a problem in setting the size of the text as specified inside listbox.

I'm trying to get the respective size corresponding to the index of the selected item but couldn't find any such method.

f = new Frame("Font");
f.setLayout(new GridLayout(3, 3));
b1 = new Button("OK");
l1 = new Label("Font :");
l2 = new Label("Size :");
l3 = new Label("Font Style :");
lb1 = new List(10, false);
lb2 = new List(10, false);
lb3 = new List(5, false);
String [] s = {"Times New Roman", "Arial", "Verdana", "Trebuchet MS", "Papyrus","Monotype Corsiva","Microsoft Sans Serif", "Courier", "Courier New"};
for(int i = 0; i < s.length; i++)
{
    lb1.add(s[i]);
}
for(int i = 8; i <=72; i += 2)
{
    lb2.add(i + "");
}
String [] s1 = {"BOLD", "ITALIC", "PLAIN"};
for(int i = 0; i < s1.length; i++)
{
    lb3.add(s1[i]);
}   

f.add(l1);
f.add(l2);
f.add(l3);
f.add(lb1);
f.add(lb2);
f.add(lb3);
f.add(b1);
b1.addActionListener(new ActionListener(){
    public void actionPerformed(ActionEvent ae)
    {
        if(lb3.isIndexSelected(0))
            fo = new Font(lb1.getSelectedItem(), Font.BOLD, **lb2.getSelectedIndex**());
        else if(lb3.isIndexSelected(1))
            fo = new Font(lb1.getSelectedItem(), Font.ITALIC, lb2.getSelectedIndex());
        else
            fo = new Font(lb1.getSelectedItem(), Font.PLAIN, lb2.getSelectedIndex());
        ta1.setFont(fo);
        MyFrame15.f.dispose(); 
    }
});
f.setSize(300, 300);
Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
int x = (int)((d.getWidth() / 2) - 200);
int y = (int)((d.getHeight() / 2) - 200);
f.setLocation(x, y);
f.setVisible(true);
}

Answer 1

To get the size as required by user we can use: lb2.getSelectedItem(); which returns a String but the third argument of Font constructor requires an integer.Therefore, we use parseInt() method of Integer class to convert the string received to integer.The code is as follows: Font(lb1.getSelectedItem(), Font.BOLD, Integer.parseInt(lb2.getSelectedItem() ));

Answer 2

I would suggest you use Swing for this. You can start with the Swing tutorial on Text Component Features which already contains a working example that does what you want.