网友您好, 请在下方输入框内输入要搜索的题目:
请选择正确的语句填入下列程序的横线处。 import javax. Swing.*; import java.awt.*; import java.awt.event.*; public class ex46 { static String str= "单击次数:"; static intcnt = 0; public static void main(String[] args) { try{ UIManager.setLookAndFeel(UIManager. getCrossPlatformLookAndFeelClassName()); } catch(Exception e) {} JFrame. jf = new JFame("ex46"); JButton jb = new JButton("Button"); jb.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent ae) { cnt ++; j1.setText(str +cnt); } }); j1. setLabelFor (jb); jPanel jp = new JPanel(); jp.setBorder(BorderFactory.createEmptyBorder(25, 25, 25, 25); jp.setLayout(new GridLayout(0, 1)); jp.add(jb); jp.add (j1); jf.getContenPanel() .add(jp, "Center"); jf.pack(); jf.setVisible (true); } }
A.Labelj1 = new JLabel(str + "0");
B.final JLabel j1 = new JLabel(str + "0");
C.final JLabelj1 = JLabel(str + "0");
D.JLabelj1 = new JLabel(str + "0");
参考答案