怎样让这个程序出来的界面正常点啊！原本是awt，但是改成swing就有问题了

[lmy901125]

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.applet.*;
import javax.swing.JOptionPane;
public class teacherchioce3 extends JFrame implements ActionListener,ItemListener
{
JFrame f=new JFrame();
JLabel lab1;
JTextField text1;
JTextArea ta1;
JButton but;
Choice cho,cho1;
String str1,str2,str[]={"王芳","刘英杰","张琳","王靖宇","黄希","蒙娜","辛婷玉","谭佳思",
"昭阳","李荣","杜晓峰","施威","雨晨","陆美贺","蒋冠明"};
public static void main(String args[])
{
new teacherchioce3();

}

teacherchioce3()
{
super("判断是否为优秀！");

addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
f.setSize(400,500);
f.setLocation(200,200);
f.setBackground(Color.darkGray);
f.setResizable(true);
f.setVisible(true);
f.setFont(new Font("Arial",Font.PLAIN,14));
//-------
cho=new Choice();
cho.add("教师");
cho.add("学生");
cho.setBounds(60,100,80,30);
f.getContentPane().add(cho);
cho.addItemListener(this);
//------
cho1=new Choice();
for(int i=0;i<str.length;i++)
{
cho1.add(str[i]);
}
cho1.setBounds(180,100,80,30);
f.getContentPane().add(cho1);
cho1.addItemListener(this);
//-------
ta1=new JTextArea(200,100);
ta1.setBounds(60,150,200,100);
f.getContentPane().add(ta1);
//------
lab1=new JLabel("您的分数：");
lab1.setBounds(60,270,60,30);
f.getContentPane().add(lab1);
//------
text1=new JTextField();
text1.setBounds(180,270,80,30);
f.getContentPane().add(text1);
text1.addActionListener(this);
//----
but=new JButton("提交");
but.addActionListener(this);
but.setBounds(210,330,50,30);
f.getContentPane().add(but);
f.show();
}
public void actionPerformed(ActionEvent e)
{

/* if(e.getSource()==but)
{

if(str1=="教师"){
if(Integer.parseInt(text1.getText())>3)
ta1.append("教师"+str2+"是优秀教师！"+"\n");
else
ta1.append("教师"+str2+"不是优秀教师！"+"\n");
}

if(str1=="学生"){
if(Integer.parseInt(text1.getText())>90)
ta1.append("学生"+str2+"是优秀学生！"+"\n");
else
ta1.append("学生"+str2+"不是优秀学生！"+"\n");

}
}*/
//------
if(e.getSource()==but)
{

if(str1=="教师"){
if(Integer.parseInt(text1.getText())>3)
ta1.setText("教师"+str2+"是优秀教师！"+"\n");
else
ta1.setText("教师"+str2+"不是优秀教师！"+"\n");
}

if(str1=="学生"){
if(Integer.parseInt(text1.getText())>90)
ta1.setText("学生"+str2+"是优秀学生！"+"\n");
else
ta1.setText("学生"+str2+"不是优秀学生！"+"\n");

}
}
}
public void itemStateChanged(ItemEvent e)
{

str1=(String)cho.getSelectedItem();
str2=(String)cho1.getSelectedItem();

}
}

[zhuzeitou]

import java.awt.*;

public class teacherchioce3 extends JFrame implements ActionListener,
		ItemListener {
	JFrame f = new JFrame();
	JLabel lab1;
	JTextField text1;
	JTextArea ta1;
	JButton but;
	Choice cho, cho1;
	String str1, str2, str[] = { "王芳", "刘英杰", "张琳", "王靖宇", "黄希", "蒙娜", "辛婷玉",
			"谭佳思", "昭阳", "李荣", "杜晓峰", "施威", "雨晨", "陆美贺", "蒋冠明" };

	public static void main(String args[]) {
		new teacherchioce3();

	}

	teacherchioce3() {
		super("判断是否为优秀！");

		f.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e) {
				System.exit(0);
			}
		});
		f.setSize(400, 500);
		f.setLocation(200, 200);
		f.setBackground(Color.darkGray);
		f.setResizable(true);
		f.setFont(new Font("Arial", Font.PLAIN, 14));
		f.getContentPane().setLayout(null);
		// -------
		cho = new Choice();
		cho.add("教师");
		cho.add("学生");
		cho.setBounds(60, 100, 80, 30);
		f.getContentPane().add(cho);
		cho.addItemListener(this);
		// ------
		cho1 = new Choice();
		for (int i = 0; i < str.length; i++) {
			cho1.add(str[i]);
		}
		cho1.setBounds(180, 100, 80, 30);
		f.getContentPane().add(cho1);
		cho1.addItemListener(this);
		// -------
		ta1 = new JTextArea(200, 100);
		ta1.setBounds(60, 150, 200, 100);
		f.getContentPane().add(ta1);
		// ------
		lab1 = new JLabel("您的分数：");
		lab1.setBounds(60, 270, 60, 30);
		f.getContentPane().add(lab1);
		// ------
		text1 = new JTextField();
		text1.setBounds(180, 270, 80, 30);
		f.getContentPane().add(text1);
		text1.addActionListener(this);
		// ----
		but = new JButton("提交");
		but.addActionListener(this);
		but.setBounds(210, 330, 50, 30);
		f.getContentPane().add(but);

		f.setVisible(true);
	}

	public void actionPerformed(ActionEvent e) {

		/*
		 * if(e.getSource()==but) {
		 * 
		 * if(str1=="教师"){ if(Integer.parseInt(text1.getText())>3)
		 * ta1.append("教师"+str2+"是优秀教师！"+"\n"); else
		 * ta1.append("教师"+str2+"不是优秀教师！"+"\n"); }
		 * 
		 * if(str1=="学生"){ if(Integer.parseInt(text1.getText())>90)
		 * ta1.append("学生"+str2+"是优秀学生！"+"\n"); else
		 * ta1.append("学生"+str2+"不是优秀学生！"+"\n");
		 * 
		 * } }
		 */
		// ------
		if (e.getSource() == but) {

			if (str1 == "教师") {
				if (Integer.parseInt(text1.getText()) > 3)
					ta1.setText("教师" + str2 + "是优秀教师！" + "\n");
				else
					ta1.setText("教师" + str2 + "不是优秀教师！" + "\n");
			}

			if (str1 == "学生") {
				if (Integer.parseInt(text1.getText()) > 90)
					ta1.setText("学生" + str2 + "是优秀学生！" + "\n");
				else
					ta1.setText("学生" + str2 + "不是优秀学生！" + "\n");

			}
		}
	}

	public void itemStateChanged(ItemEvent e) {

		str1 = (String) cho.getSelectedItem();
		str2 = (String) cho1.getSelectedItem();

	}
}

做了最基础的修改，可以正常显示和退出了
问题还有很多，慢慢去改吧