selectsubjectframe.java

java编写的桌面考试系统.含所有源码.

package exam.gui;

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;

import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;

import exam.dao.SubjectFromCfg;
import exam.model.Student;

/**
 * 选择科目界面
 * 
 * @author 刘东
 * 
 */
public class SelectSubjectFrame implements ActionListener {
	private JFrame frame;
	private JLabel welcomeL, selectL;
	private JButton start, quit;
	private JComboBox select;
	private JPanel pc, ps;
	private String[] items;
	private Student student;

	public SelectSubjectFrame(Student student) {

		this.student = student;
		frame = new JFrame("选择考试科目");
		items = new SubjectFromCfg().getItems();
		welcomeL = new JLabel("        " + student.getUserName()
				+ ",欢迎进入大内考试系统");
		selectL = new JLabel("请选择考试科目:");
		select = new JComboBox(items);
		start = new JButton("开始考试");
		quit = new JButton("退出");
		pc = new JPanel();
		ps = new JPanel();

		init();
	}

	private void init() {
		pc.add(selectL);
		pc.add(select);

		ps.add(start);
		start.addActionListener(this);
		ps.add(quit);
		quit.addActionListener(this);

		frame.add(welcomeL, BorderLayout.NORTH);
		frame.add(pc, BorderLayout.CENTER);
		frame.add(ps, BorderLayout.SOUTH);

		frame.setSize(240, 180);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setVisible(true);
		frame.setResizable(false);

		setThisLocation();
	}

	public void actionPerformed(ActionEvent arg0) {
		JButton b = (JButton) arg0.getSource();
		if (b.getText().equals("开始考试")) {
			String subject = (String) select.getSelectedItem();
			if (!new File(new SubjectFromCfg().getFileName(subject)).exists()) {
				JOptionPane.showMessageDialog(frame, "该科目暂不提供考试！", "操作提示",
						JOptionPane.WARNING_MESSAGE);
			} else {
				frame.dispose();
				new ExamMainFrame(student, subject);
			}
		}
		if (b.getText().equals("退出")) {
			frame.dispose();
		}
	}

	private void setThisLocation() {
		Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
		Dimension frameSize = frame.getSize();
		if (frameSize.height > screenSize.height) {
			frameSize.height = screenSize.height;
		}
		if (frameSize.width > screenSize.width) {
			frameSize.width = screenSize.width;
		}
		frame.setLocation((screenSize.width - frameSize.width) / 2,
				(screenSize.height - frameSize.height) / 2);
		frame.setVisible(true);
	}
}