[分享]计算器原代码
import lundin.SymbolicMath.Eval;
import lundin.SymbolicMath.Derive;
import java.applet.Applet;
import java.util.*;
import java.awt.*;
public class Calculator extends Applet{
Panel p = null;
Panel p1 = null;
Panel p2 = null;
Panel p3 = null;
Label lbl = null;
Eval ev = null; //
Derive de = null; //??等号
TextField tf = null;
Button info = null;
Button clear = null;
Button equa = null;
Button plus = null;
Button minus = null;
Button divide = null;
Button mult = null;
Button zerow,one,two,three,four,five,six,seven,eight,nine,point;
Hashtable values = null;
Font fo = null;
FontMetrics fm = null;
public void init()
{
int color = 0x999966;
GridBagLayout gridb = new GridBagLayout();
GridBagLayout gridb2 = new GridBagLayout();
GridBagLayout gridb3 = new GridBagLayout();
GridBagConstraints constr = new GridBagConstraints();
String temp = "";
ev = new Eval();
de = new Derive();
values = new Hashtable();
fo = new Font("Times Roman", Font.PLAIN, 9 );
this.setFont( fo );
fm = this.getFontMetrics( fo );
p = new Panel();
p1 = new Panel();
p2 = new Panel();
p3 = new Panel();
tf = new TextField();
info = new Button( "Info" );
clear = new Button( "Clear" );
plus = new Button( "+" );
minus = new Button( "-" );
mult = new Button( "*" );
divide = new Button( "/" );
equa = new Button( "=" );
point = new Button(".");
zerow = new Button("0");
one = new Button("1");
two = new Button("2");
three = new Button("3");
four = new Button("4");
five = new Button("5");
six = new Button("6");
seven = new Button("7");
eight = new Button("8");
nine = new Button("9");
this.setBackground( new Color(color) ); //设置背景颜色
p2.setLayout( gridb );
p2.setBackground( new Color(color) );
p2.setForeground( Color.black );
p3.setBackground( new Color(color) );
p3.setForeground( Color.black );
tf.setBackground( Color.white );
tf.setForeground( Color.black );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 0;
constr.gridy = 0;
constr.ipadx = 3;
constr.ipady = 3;
gridb.setConstraints( seven , constr );
p2.add( seven);
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 1;
constr.gridy = 0;
gridb.setConstraints( eight , constr );
p2.add( eight );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 2;
constr.gridy = 0;
gridb.setConstraints( nine , constr );
p2.add( nine );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 3;
constr.gridy = 0;
gridb.setConstraints( plus , constr );
p2.add( plus );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 0;
constr.gridy = 1;
gridb.setConstraints( four , constr );
p2.add( four );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 1;
constr.gridy = 1;
gridb.setConstraints( five , constr );
p2.add( five );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 2;
constr.gridy = 1;
gridb.setConstraints( six , constr );
p2.add( six );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 3;
constr.gridy = 1;
gridb.setConstraints( minus , constr );
p2.add( minus );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 0;
constr.gridy = 2;
gridb.setConstraints( one , constr );
p2.add( one );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 1;
constr.gridy = 2;
gridb.setConstraints( two , constr );
p2.add( two );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 2;
constr.gridy = 2;
gridb.setConstraints( three , constr );
p2.add( three );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 3;
constr.gridy = 2;
gridb.setConstraints( mult , constr );
p2.add( mult );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 0;
constr.gridy = 3;
gridb.setConstraints( equa , constr );
p2.add( equa );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 1;
constr.gridy = 3;
gridb.setConstraints( zerow , constr );
p2.add( zerow );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 2;
constr.gridy = 3;
gridb.setConstraints( point , constr );
p2.add( point );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 3;
constr.gridy = 3;
gridb.setConstraints( divide , constr );
p2.add( divide );
p1.setLayout( gridb3 );
p1.setBackground( new Color(color) );
p1.setForeground( Color.black );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 0;
constr.gridy = 0;
gridb3.setConstraints( clear , constr );
p1.add( clear );
constr.fill = GridBagConstraints.NONE;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 1;
constr.gridy = 0;
gridb3.setConstraints( info , constr );
p1.add( info );
p.setLayout( gridb2 );
p.setBackground( new Color(color) );
p.setForeground( Color.black );
constr.fill = GridBagConstraints.HORIZONTAL;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 0;
constr.gridy = 0;
gridb2.setConstraints( tf , constr );
p.add( tf );
constr.fill = GridBagConstraints.HORIZONTAL;
constr.anchor = GridBagConstraints.CENTER;
constr.gridx = 0;
constr.gridy = 1;
gridb2.setConstraints( p2 , constr );
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p.add( p2 ); constr.fill = GridBagConstraints.NONE; constr.anchor = GridBagConstraints.CENTER; constr.gridx = 0; constr.gridy = 2; gridb2.setConstraints( p1 , constr ); p.add( p1 ); constr.fill = GridBagConstraints.NONE; constr.anchor = GridBagConstraints.CENTER; constr.gridx = 0; constr.gridy = 3; gridb2.setConstraints( p3 , constr ); p.add( p3 ); this.add( p ); try{ System.out.println("\n\nApplet Calculator Made by Patrik Lundin, f95-plu@nada.kth.se\n\n"); }catch(Exception ex){} } void evaluate() { String temp = ""; String tmp = ""; int ind1 = 0; int ind2 = 0; try{ tmp = prepare( tf.getText().toLowerCase() ); if( tmp.equals("") ){ return; } // check if is diff, set or clear() command. if( ( ind1 = tmp.indexOf("diff(")) != -1 ){ temp = de.diff( tmp.substring( ind1 + 5, tmp.lastIndexOf(")")))[0]; if( de.VARIABLES.indexOf(";") != -1 ){ tf.setText("Error: Multiple variables"); return; }else{ tf.setText( temp ); return; } }else if( ( ind1 = tmp.indexOf("set(") ) != -1 ){ try{ ind2 = tmp.lastIndexOf(")"); temp = tmp.substring( ind1 + 4, ind2 ); values.put( temp.substring( 0,temp.indexOf("=")) , temp.substring( temp.indexOf("=") + 1, temp.length())); tf.setText("Value set, " + getValues()); }catch(Exception ex){ tf.setText("Syntax error, " + tmp); } return; }else if( ( ind1 = tmp.indexOf("clear(")) != -1 ){ if( (ind2 = tmp.lastIndexOf(")")) == -1 ){ tf.setText("Non matching brackets"); return; } temp = tmp.substring( ind1 + 6 , ind2 ); values.remove( temp ); tf.setText( "Value cleared, " + getValues() ); return; }else if( tmp.indexOf("memory") != -1 ){ tf.setText( getValues() ); return; } // normal, evaluate. tf.setText( String.valueOf(ev.eval( tmp , values))); }catch(Exception ex){ tf.setText( ex.getMessage()); } } String getValues() { String temp = ""; String tmp = ""; Enumeration en = values.keys(); while( en.hasMoreElements() ){ tmp = (String)en.nextElement(); if( temp.equals("") ){ temp = tmp + "=" + (String)values.get( tmp ); }else{ temp += ";" + tmp + "=" + (String)values.get( tmp ); } } return temp; } public boolean keyDown(Event event, int key) { char c = (char)key; tf.requestFocus(); if( c == '\n' ){ evaluate(); return true; } return false; } public boolean handleEvent(Event event) { if( event.id == Event.ACTION_EVENT ){ if( event.target == info ){ new Msg("Info", information() ); return true; }else if( event.target == equa ){ evaluate(); return true; }else if( event.target == clear ){ tf.setText(""); return true; } } return super.handleEvent(event); } public boolean action(Event event, Object ob) { if( event.target instanceof Button ){ tf.setText( tf.getText() + (String)ob ); return true; } return false; } String information() { String message = "wwmm2xll" return message; } String prepare(String str) { String nstr = ""; int i = 0; int count = 0; while( i < str.length() ){ if(str.charAt( i ) == '('){ count++; }else if(str.charAt( i ) == ')'){ count--; } if( str.charAt( i ) != ' ' ){ nstr += str.charAt( i ); } i++; } if( count != 0 ){ tf.setText("Non matching brackets, " + str); return ""; } return nstr; } }// end class calculator. class Msg extends Frame{ public Msg(String title, String message) { super(); GridBagLayout gridb = new GridBagLayout(); GridBagConstraints constr = new GridBagConstraints(); Msg a = new Msg(title); a.setLayout( gridb ); TextArea p = new TextArea( message ); p.resize( 250 , 250 ); Button b = new Button("OK, Close This Window"); constr.fill = GridBagConstraints.BOTH; constr.anchor = GridBagConstraints.NORTH; constr.gridx = 0; constr.gridy = 0; gridb.setConstraints( p , constr ); a.add( p ); constr.fill = GridBagConstraints.HORIZONTAL; constr.anchor = GridBagConstraints.CENTER; constr.gridx = 0; constr.gridy = 1; gridb.setConstraints( b , constr ); a.add( b ); a.pack(); a.show(); } public Msg(String s) { super(s); } public boolean action(Event ev, Object o) { this.hide(); this.dispose(); return true; } } // end class Msg.
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你不把自己的包发上来 我们怎么编译？？
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弄下来看看 哎 好多类和方法原来都没见过 搬着书挨个查 学的好艰辛啊
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有错误
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