Piccaboo:
Im tener un problema en el cálculo (). Cuando abro la calculadora cuando pulso a 0 - 2 o 0 * 2 o 0/2 siempre resulta que el número lo que he entrado antes del cero. Si No hago otra cosa que si el código del primer número cuando abro mi conteo calculadora no funciona. Por favor ayuda me im un novato cuando se trata de la programación.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Toolkit;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.SwingConstants;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JLabel;
import javax.swing.border.Border;
import javax.swing.border.LineBorder;
public class Calculator{
private JFrame frame;
private JButton btnX;
private JButton button_1, button;
private JButton button_2;
private JLabel label;
private JLabel label2;
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, button_15;
private JButton button_11, button_14;
private JButton button_12, button_16;
private JButton button_13, button_17;
private JButton button_22;
private Double result = 0.0;
private Double inverse;
private Double squareRoot;
private Double square;
private Double percent;
private boolean newin = true;
private String arg = "";
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
Calculator window = new Calculator();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public Calculator() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
ImageIcon image = new ImageIcon("D:/Programming/MyApps/src/1440353685_MB__calculator.png");
frame = new JFrame();
KeyListener l = new KeyListener() {
@Override
public void keyPressed(KeyEvent e) {
switch (e.getKeyCode()) {
case KeyEvent.VK_0 :
case KeyEvent.VK_NUMPAD0 : button_9.doClick();
break;
case KeyEvent.VK_NUMPAD1 :
case KeyEvent.VK_1 : button.doClick();
break;
case KeyEvent.VK_2 :
case KeyEvent.VK_NUMPAD2 : button_1.doClick();
break;
case KeyEvent.VK_3 :
case KeyEvent.VK_NUMPAD3 : button_2.doClick();
break;
case KeyEvent.VK_4 :
case KeyEvent.VK_NUMPAD4 : button_3.doClick();
break;
case KeyEvent.VK_5 :
case KeyEvent.VK_NUMPAD5 : button_4.doClick();
break;
case KeyEvent.VK_6 :
case KeyEvent.VK_NUMPAD6 : button_5.doClick();
break;
case KeyEvent.VK_7 :
case KeyEvent.VK_NUMPAD7 : button_6.doClick();
break;
case KeyEvent.VK_8 : if (e.isShiftDown()) button_14.doClick();
else button_7.doClick();
break;
case KeyEvent.VK_NUMPAD8 : button_7.doClick();
break;
case KeyEvent.VK_9 :
case KeyEvent.VK_NUMPAD9 : button_8.doClick();
break;
case KeyEvent.VK_PERIOD :
case KeyEvent.VK_DECIMAL : button_13.doClick();
break;
case KeyEvent.VK_EQUALS : if(e.isShiftDown()) button_12.doClick();
else button_17.doClick();
break;
case KeyEvent.VK_ENTER : button_17.doClick();
break;
case KeyEvent.VK_MINUS :
case KeyEvent.VK_SUBTRACT : button_11.doClick();
break;
case KeyEvent.VK_C : button_16.doClick();
break;
case KeyEvent.VK_ADD : button_12.doClick();
break;
case KeyEvent.VK_MULTIPLY : button_14.doClick();
break;
case KeyEvent.VK_DIVIDE :
case KeyEvent.VK_SLASH : button_15.doClick();
break;
case KeyEvent.VK_BACK_SPACE : btnX.doClick();
break;
case KeyEvent.VK_AMPERSAND : button_22.doClick();
}
}
@Override
public void keyReleased(KeyEvent e) {
}
@Override
public void keyTyped(KeyEvent e) {
// TODO Auto-generated method stub
}
};
frame.setResizable(false);
frame.setBounds(100, 100, 289, 452);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("Calculator");
frame.addKeyListener(l);
frame.setIconImage(image.getImage());
frame.getContentPane().setLayout(null);
Border border = LineBorder.createGrayLineBorder();
button = new JButton("1");
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if (label.getText().length() == 22) {
Toolkit.getDefaultToolkit().beep();
return;
}
if (label.getText().equals("0") || newin) label.setText("");
label.setText(label.getText() + "1");
newin = false;
}
});
button.setBounds(10, 68, 47, 34);
button.setFocusable(false);
button.setContentAreaFilled(false);
frame.getContentPane().add(button);
btnX = new JButton("<X");
btnX.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (label.getText().length() > 0 && !label.getText().equals("0")) {
label.setText(label.getText().substring(0, label.getText().length()-1));
}
if (label.getText().length() == 0) label.setText("0");
}
});
btnX.setBounds(224, 68, 49, 34);
btnX.setFocusable(false);
btnX.setToolTipText("Press \"Backspace\" instead");
btnX.setContentAreaFilled(false);
frame.getContentPane().add(btnX);
button_1 = new JButton("2");
button_1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (label.getText().length() == 22) {
Toolkit.getDefaultToolkit().beep();
return;
}
if (label.getText().equals("0") || newin) label.setText("");
label.setText(label.getText() + "2");
newin = false;
}
});
button_1.setBounds(59, 68, 47, 34);
button_1.setFocusable(false);
button_1.setContentAreaFilled(false);
frame.getContentPane().add(button_1);
button_2 = new JButton("3");
button_2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (label.getText().length() == 22) {
Toolkit.getDefaultToolkit().beep();
return;
}
if (label.getText().equals("0") || newin) label.setText("");
label.setText(label.getText() + "3");
newin = false;
}
});
button_2.setBounds(108, 68, 47, 34);
button_2.setFocusable(false);
button_2.setContentAreaFilled(false);
frame.getContentPane().add(button_2);
label2 = new JLabel("");
label2.setBounds(10, 15, 260, 14);
label2.setOpaque(true);
label2.setBackground(Color.WHITE);
label2.setFont(new Font("Arial", Font.BOLD, 10));
label2.setHorizontalAlignment(SwingConstants.RIGHT);
label = new JLabel("0");
label.setHorizontalAlignment(SwingConstants.RIGHT);
label.setVerticalAlignment(SwingConstants.BOTTOM);
label.setOpaque(true);
label.setBackground(Color.white);
label.setBorder(border);
label.setLayout(new BorderLayout());
label.setFont(new Font("Arial", Font.BOLD, 20));
label.add(label2, BorderLayout.PAGE_START);
label.setBounds(10, 11, 265, 42);
frame.getContentPane().add(label);
button_3 = new JButton("4");
button_3.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if (label.getText().length() == 22) {
Toolkit.getDefaultToolkit().beep();
return;
}
if (label.getText().equals("0")) label.setText("");
label.setText(label.getText() + "4");
newin = false;
}
});
button_3.setBounds(10, 113, 47, 34);
button_3.setFocusable(false);
button_3.setContentAreaFilled(false);
frame.getContentPane().add(button_3);
button_4 = new JButton("5");
button_4.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if (label.getText().length() == 22) {
Toolkit.getDefaultToolkit().beep();
return;
}
if (label.getText().equals("0") || newin) label.setText("");
label.setText(label.getText() + "5");
newin = false;
}
});
button_4.setBounds(59, 113, 47, 34);
button_4.setFocusable(false);
button_4.setContentAreaFilled(false);
frame.getContentPane().add(button_4);
button_5 = new JButton("6");
button_5.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if (label.getText().length() == 22) {
Toolkit.getDefaultToolkit().beep();
return;
}
if (label.getText().equals("0") || newin) label.setText("");
label.setText(label.getText() + "6");
newin = false;
}
});
button_5.setBounds(108, 113, 47, 34);
button_5.setFocusable(false);
button_5.setContentAreaFilled(false);
frame.getContentPane().add(button_5);
button_6 = new JButton("7");
button_6.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if (label.getText().length() == 22) {
Toolkit.getDefaultToolkit().beep();
return;
}
if (label.getText().equals("0") || newin) label.setText("");
label.setText(label.getText() + "7");
newin = false;
}
});
button_6.setBounds(10, 160, 47, 34);
button_6.setFocusable(false);
button_6.setContentAreaFilled(false);
frame.getContentPane().add(button_6);
button_7 = new JButton("8");
button_7.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if (label.getText().length() == 22) {
Toolkit.getDefaultToolkit().beep();
return;
}
if (label.getText().equals("0") || newin) label.setText("");
label.setText(label.getText() + "8");
newin = false;
}
});
button_7.setBounds(59, 160, 47, 34);
button_7.setFocusable(false);
button_7.setContentAreaFilled(false);
frame.getContentPane().add(button_7);
button_8 = new JButton("9");
button_8.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if (label.getText().length() == 22) {
Toolkit.getDefaultToolkit().beep();
return;
}
if (label.getText().equals("0") || newin) label.setText("");
label.setText(label.getText() + "9");
newin = false;
}
});
button_8.setBounds(108, 160, 47, 34);
button_8.setFocusable(false);
button_8.setContentAreaFilled(false);
frame.getContentPane().add(button_8);
button_9 = new JButton("0");
button_9.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (label.getText().length() == 22) {
Toolkit.getDefaultToolkit().beep();
return;
}
if (label.getText().equals("0") || newin) label.setText("");
label.setText(label.getText() + "0");
newin = false;
}
});
button_9.setFocusable(false);
button_9.setContentAreaFilled(false);
button_9.setBounds(59, 205, 47, 34);
frame.getContentPane().add(button_9);
JButton button_10 = new JButton("±");
button_10.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if (label.getText().equals("0")) return;
if (label.getText().substring(0, 1).equals("-")) label.setText(label.getText().substring(1));
else label.setText("-" + label.getText());
}
});
button_10.setFocusable(false);
button_10.setContentAreaFilled(false);
button_10.setBounds(165, 68, 49, 34);
frame.getContentPane().add(button_10);
button_11 = new JButton("-");
button_11.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (newin && !label2.getText().equals("")) {
String in = reverseString(label2.getText());
in = in.substring(1);
in = "-" + in;
label2.setText("");
label2.setText(reverseString(in));
arg = "-";
} else {
label2.setText(label2.getText() + " " + label.getText() + " -");
calculate();
arg = "-";
label.setText(removeZeros(result));
newin = true;
}
}
});
button_11.setFocusable(false);
button_11.setContentAreaFilled(false);
button_11.setBounds(165, 113, 49, 34);
frame.getContentPane().add(button_11);
button_12 = new JButton("+");
button_12.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (newin && !label2.getText().equals("")) {
String in = reverseString(label2.getText());
in = in.substring(1);
in = "+" + in;
label2.setText("");
label2.setText(reverseString(in));
arg = "+";
} else {
label2.setText(label2.getText() + " " + label.getText() + " +");
calculate();
arg = "+";
label.setText(removeZeros(result));
newin = true;
}
}
});
button_12.setFocusable(false);
button_12.setContentAreaFilled(false);
button_12.setBounds(165, 157, 49, 82);
frame.getContentPane().add(button_12);
button_13 = new JButton(".");
button_13.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
for (int i = 0; i < label.getText().length(); i++) {
char a = label.getText().charAt(i);
if (a == '.') return;
}
label.setText(label.getText() + ".");
}
});
button_13.setFocusable(false);
button_13.setContentAreaFilled(false);
button_13.setBounds(108, 205, 47, 34);
frame.getContentPane().add(button_13);
button_14 = new JButton("x");
button_14.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if (newin && !label2.getText().equals("")) {
String in = reverseString(label2.getText());
in = in.substring(1);
in = "x" + in;
label2.setText("");
label2.setText(reverseString(in));
arg = "*";
} else {
label2.setText(label2.getText() + " " + label.getText() + " x");
calculate();
arg = "*";
label.setText(removeZeros(result));
newin = true;
}
}
});
button_14.setFocusable(false);
button_14.setContentAreaFilled(false);
button_14.setBounds(224, 160, 49, 34);
frame.getContentPane().add(button_14);
button_15 = new JButton("/");
button_15.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if (newin && !label2.getText().equals("")) {
String in = reverseString(label2.getText());
in = in.substring(1);
in = "/" + in;
label2.setText("");
label2.setText(reverseString(in));
arg = "/";
} else {
label2.setText(label2.getText() + " " +
removeZeros(Double.valueOf(label.getText())) + " /");
calculate();
arg = "/";
label.setText(removeZeros(result));
newin = true;
}
}
});
button_15.setFocusable(false);
button_15.setContentAreaFilled(false);
button_15.setBounds(224, 205, 49, 34);
frame.getContentPane().add(button_15);
button_16 = new JButton("C");
button_16.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
label.setText("0");
label2.setText("");
result = 0.0;
arg = "";
newin = false;
}
});
button_16.setFocusable(false);
button_16.setToolTipText("Press \"C\" instead");
button_16.setContentAreaFilled(false);
button_16.setBounds(224, 113, 49, 34);
frame.getContentPane().add(button_16);
button_17 = new JButton("=");
button_17.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
calculate();
label.setText(removeZeros(result));
label2.setText("");
arg = "";
newin = true;
result = 0.0;
}
});
button_17.setFocusable(false);
button_17.setContentAreaFilled(false);
button_17.setBounds(10, 205, 47, 34);
frame.getContentPane().add(button_17);
button_22 = new JButton("1/x");
button_22.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
label2.setText(("reciproc"+ "("+label.getText()+")"));
inverse = 1/Double.parseDouble(label.getText());
label.setText(removeZeros(inverse));
}
});
button_22.setFocusable(false);
button_22.setContentAreaFilled(false);
button_22.setBounds(76, 270, 63, 60);
frame.getContentPane().add(button_22);
}
private void calculate() {
if (result == 0) {
result = Double.valueOf(label.getText());
return;
}
switch (arg) {
case "+" : result += Double.parseDouble(label.getText());
break;
case "-" : result -= Double.parseDouble(label.getText());
break;
case "*" : result *= Double.valueOf(label.getText());
break;
case "/" : result /= Double.valueOf(label.getText());
break;
}
}
private String removeZeros(Double n) {
String in = String.valueOf(n);
while (in.indexOf(".") != -1) {
if (in.substring(in.length() - 1).equals("0") ||
in.substring(in.length() - 1).equals("."))
in = in.substring(0, in.length() - 1);
else break;
}
return in;
}
private String reverseString(String input) {
String output = "";
for (int i = input.length() - 1; i > -1; i--) {
output += input.charAt(i);
}
return output;
}
}
Alex:
El problema es que cuando se introduce un cero seguido de cualquier operación y luego introduce un operando, entonces la variable 'resultado' es cero, por lo que 'Calcular ()' tratar esta situación como usted no ha entrado nada todavía, y se pone justo ' resultar' a la nueva operando en lugar de realizar '0 (funcionamiento) (operando)'.
Se puede resolver si se añade una nueva variable booleana 'isClear', que en un inicio se establece en true. Cada vez que se pulsa un botón con alguna operación establece esta variable a falso. En el método de cálculo () reemplazar
if (result == 0) {
result = Double.valueOf(label.getText());
return;
}
con
if (isClear) {
result = Double.valueOf(label.getText());
return;
}
También debe establecer 'isClear' true cuando se presiona el botón 'C' para borrar la entrada.