实例介绍
【实例简介】
【实例截图】
【核心代码】
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class calculator extends Frame implements ActionListener, WindowListener
{
private Container container;
private GridBagLayout layout;
private GridBagConstraints constraints;
private JTextField displayField; //计算结果显示区
private String lastCommand; //保存 ,-,*,/,=命令0
private double result; //保存计算结果
private boolean start; //判断是否为数字的开始
private JMenuBar menubar;
private JMenuItem m_exit;
private JMenuItem m2_ejz;
private JMenuItem m2_bjz;
private Dialog dialog;
private Label label_dialog;
private JButton button_sqrt;
private JButton button_plusminus;
private JButton button_CE;
private JButton button_cancel;
private JButton button_1;
private JButton button_2;
private JButton button_3;
private JButton button_4;
private JButton button_5;
private JButton button_6;
private JButton button_7;
private JButton button_8;
private JButton button_9;
private JButton button_0;
private JButton button_plus;
private JButton button_minus;
private JButton button_multiply;
private JButton button_divide;
private JButton button_point;
private JButton button_equal;
private JButton button_log;
private JButton button_tan;
private JButton button_cos;
private JButton button_sin;
private JButton button_exp;
public calculator() //构造方法设置布局、为按钮注册事件监听器
{
super( "My Calculator" );
this.setLocation( 350,150 );
this.setSize( 450,400 );
this.setResizable( true );
this.setLayout( new GridLayout( 7,1 ) );
this.addmyMenu(); //调用成员方法添加菜单
displayField = new JTextField( 30 );
this.add( displayField );
displayField.setEditable( true );
start = true;
result = 0;
lastCommand = "=";
JPanel panel0 = new JPanel();
panel0.setLayout( new GridLayout( 1,4,4,4 ) );
JPanel panel1 = new JPanel();
panel1.setLayout( new GridLayout( 1,5,4,4 ) );
this.add( panel1 );
button_sqrt = new JButton( "sqrt" );//根号
button_plusminus = new JButton( " /-" );
button_exp = new JButton( "exp" );//底数e的n次幂
button_CE = new JButton( "退位");
button_cancel = new JButton( "c" );//清除
JPanel panel2 = new JPanel();
panel2.setLayout( new GridLayout( 1,5,4,4 ) );
this.add( panel2 );
button_7 = new JButton( "7" );
button_8 = new JButton( "8" );
button_9 = new JButton( "9" );
button_log = new JButton( "log" );//对数
button_divide = new JButton( "/" );//除
JPanel panel3 = new JPanel();
panel3.setLayout( new GridLayout(1,5,4,4) );
this.add( panel3 );
button_4 = new JButton( "4" );
button_5 = new JButton( "5" );
button_6 = new JButton( "6" );
button_tan = new JButton( "tan" );//正切
button_multiply = new JButton( "*" );//乘法
JPanel panel4=new JPanel();
panel4.setLayout( new GridLayout( 1,5,4,4 ) );
this.add(panel4);
button_1 = new JButton( "1" );
button_2 = new JButton( "2" );
button_3 = new JButton( "3" );
button_cos = new JButton( "cos");//余弦
button_minus = new JButton( "-" );
JPanel panel5 = new JPanel();
panel5.setLayout( new GridLayout( 1,5,4,4 ) );
this.add( panel5 );
button_0 = new JButton( "0" );
button_point=new JButton( "." );
button_equal = new JButton( "=" );
button_sin = new JButton( "sin" );//正弦
button_plus = new JButton( " " );
panel1.add( button_sqrt );
panel1.add( button_plusminus );
panel1.add( button_exp );
panel1.add( button_CE );
panel1.add( button_cancel );
panel2.add( button_7 );
panel2.add( button_8 );
panel2.add( button_9 );
panel2.add( button_log );
panel2.add( button_divide );
panel3.add( button_4 );
panel3.add( button_5 );
panel3.add( button_6 );
panel3.add( button_tan );
panel3.add( button_multiply );
panel4.add( button_1 );
panel4.add( button_2 );
panel4.add( button_3 );
panel4.add( button_cos );
panel4.add( button_minus );
panel5.add( button_0 );
panel5.add( button_point );
panel5.add( button_equal );
panel5.add( button_sin );
panel5.add( button_plus) ;
button_sqrt.addActionListener( this );
button_plusminus.addActionListener( this );
button_exp.addActionListener( this );
button_CE.addActionListener( this );
button_cancel.addActionListener( this );
button_7.addActionListener( this );
button_8.addActionListener( this );
button_9.addActionListener( this );
button_log.addActionListener( this );
button_divide.addActionListener( this );
button_4.addActionListener( this );
button_5.addActionListener( this );
button_6.addActionListener( this );
button_tan.addActionListener( this );
button_multiply.addActionListener( this );
button_1.addActionListener( this );
button_2.addActionListener( this );
button_3.addActionListener( this );
button_cos.addActionListener( this );
button_minus.addActionListener( this );
button_0.addActionListener( this );
button_point.addActionListener( this );
button_equal.addActionListener( this );
button_sin.addActionListener( this );
button_plus.addActionListener( this );
this.addWindowListener( new WinClose() ); //注册窗口监听器
this.setVisible( true );
}
private void addmyMenu() //菜单的添加
{
JMenuBar menubar = new JMenuBar();
this.add( menubar );
JMenu m1 = new JMenu( "选项" );
JMenu m2 = new JMenu( "进制转换" );
JMenuItem m1_exit = new JMenuItem( "退出" );
m1_exit.addActionListener( this );
JMenuItem m2_ejz = new JMenuItem( "二进制" );
m2_ejz.addActionListener( this );
JMenuItem m2_bjz = new JMenuItem("八进制");
m2_bjz.addActionListener( this );
JMenuItem m2_sljz = new JMenuItem("十六进制");
m2_sljz.addActionListener( this );
JMenu m3 = new JMenu( "帮助" );
JMenuItem m3_Help = new JMenuItem( "用法" );
m3_Help.addActionListener( this );
dialog = new Dialog( this, "提示" , true ); //模式窗口
dialog.setSize( 240,80 );
label_dialog = new Label("", Label.CENTER ); //标签的字符串为空，居中对齐
dialog.add( label_dialog );
dialog.addWindowListener( this ); //为对话框注册窗口事件监听器
m1.add( m1_exit );
menubar.add( m1 );
m2.add( m2_ejz );
m2.add( m2_bjz );
m2.add( m2_sljz );
menubar.add( m2 );
m3.add( m3_Help );
menubar.add( m3 );
}
public void actionPerformed(ActionEvent e) //按钮的单击事件处理方法
{
if(
e.getSource().equals( button_1 )||e.getSource().equals( button_2 )||
e.getSource().equals( button_3 )||e.getSource().equals( button_4 )||
e.getSource().equals( button_5 )|| e.getSource().equals( button_6 )||
e.getSource().equals( button_7 )|| e.getSource().equals( button_8 )||
e.getSource().equals( button_9 ) ||e.getSource().equals( button_0 )||
e.getSource().equals( button_point )||e.getSource().equals( button_plusminus )||
e.getSource().equals( button_cancel )||e.getSource().equals( button_CE )
)
{ //非运算符的处理方法
String input = e.getActionCommand();
if ( start )
{
displayField.setText("");
start = false;
if( input.equals( " /-" ) )
displayField.setText( displayField.getText() "-" );
}
if( !input.equals( " /-" ) )
{
String str = displayField.getText();
if( input.equals( "退格" ) ) //退格键的实现方法
{
if( str.length() > 0 )
displayField.setText( str.substring( 0,str.length() - 1 ) );
}
else if( input.equals( "C" ) ) //清零键的实现方法
{
displayField.setText( "0" );
start = true;
}
else
displayField.setText( displayField.getText() input );
}
}
else if ( e.getActionCommand() == "二进制" ) //二进制的转换
{
int n = Integer.parseInt( displayField.getText() );
displayField.setText( Integer.toBinaryString( n ) );
}
else if ( e.getActionCommand() == "八进制" ) //八进制的转换
{
int n = Integer.parseInt( displayField.getText() );
displayField.setText( Integer.toOctalString( n ) );
}
else if ( e.getActionCommand() == "十六进制" ) //十六进制的转换
{
int n = Integer.parseInt( displayField.getText() );
displayField.setText( Integer.toHexString( n ) );
}
else if ( e.getActionCommand() == "退出" ) //选项中退出的处理方法
{
System.exit( 0 );
}
else if ( e.getActionCommand() == "用法" ) //按下'帮助'菜单栏中用法的处理方法
{
label_dialog.setText( "sqrt,exp等键是先输运算符再输数字\n" );
dialog.setLocation( 400,250 );
dialog.setVisible( true );
}
else //各运算符的识别
{
String command = e.getActionCommand();
if( start )
{
lastCommand = command;
}
else
{
calculate( Double.parseDouble( displayField.getText() ) );
lastCommand = command;
start = true;
}
}
}
public void calculate( double x ) //各运算符的具体运算方法
{
double d = 0;
if ( lastCommand.equals( " " ) )
result = x;
else if (lastCommand.equals( "-" ) )
result -= x;
else if ( lastCommand.equals( "*" ) )
result *= x;
else if ( lastCommand.equals( "/" ) )
result /= x;
else if ( lastCommand.equals( "=" ) )
result = x;
else if ( lastCommand.equals( "sqrt" ) )
{
d = Math.sqrt( x );
result = d;
}
else if ( lastCommand.equals( "exp" ) )
{
d = Math.exp( x );
result = d;
}
else if ( lastCommand.equals( "log" ) )
{
d = Math.log( x );
result = d;
}
else if ( lastCommand.equals( "tan" ) )
{
d = Math.tan(x);
result = d;
}
else if ( lastCommand.equals( "cos" ) )
{
d = Math.cos( x );
result = d;
}
else if ( lastCommand.equals( "sin" ) )
{
d = Math.sin( x );
result = d;
}
displayField.setText( "" result );
}
public void windowClosing( WindowEvent e )
{
if( e.getSource() == dialog )
dialog.setVisible( false ); //隐藏对话框
else
System.exit( 0 );
}
public void windowOpened( WindowEvent e ) { }
public void windowActivated( WindowEvent e ) { }
public void windowDeactivated( WindowEvent e ) { }
public void windowClosed( WindowEvent e ) { }
public void windowIconified( WindowEvent e ) { }
public void windowDeiconified( WindowEvent e ) { }
public static void main( String args[] )
{
calculator calculator = new calculator();
}
}
class WinClose implements WindowListener
{
public void windowClosing( WindowEvent e ) //单击窗口关闭按钮时触发并执行实现窗口监听器接口中的方法
{
System.exit( 0 ); //结束程序运行
}
public void windowOpened( WindowEvent e ){ }
public void windowActivated( WindowEvent e ){}
public void windowDeactivated( WindowEvent e){ }
public void windowClosed( WindowEvent e ){ }
public void windowIconified( WindowEvent e ){ }
public void windowDeiconified( WindowEvent e ){ }
}
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