问题
Using Java, and JavaFX, I made a Scientific Calculator, but it has a problem with clearing after the answers on the "Scientific" buttons. It clears after the +/-/// equations, but not on like, square root, or tangent.
For example:
Say I did 1 + 1, then pressed = and got 2. If I pressed another number, it would clear first, not just add onto the number like this: 25
But like this: 5 And if I pressed +/-/// button, it would clear the text area, too of course, so that the user could put in another number.
Here's another example: Say I did 4 * 8, and got 32. If I pressed another number, it would clear first, not just add onto the number like this: 327 But like this: 7 And if I pressed +/-/*// button, it would clear the text area, too of course, so that the user could put in another number.
But here's a case with a problem: Say I did 16 , then pressed square root and got 4. If I pressed another number, it would just add onto the original number like this: 323 Not like this: 3 That's the problem with all the other scientific buttons, too.
Here's some code(my FXML controller class):
package calculator;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.Node;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.input.KeyCode;
import javafx.stage.Stage;
public class ScienCalController implements Initializable {
double data = 0d;
int operation = -1;
private boolean start = false;
private boolean hypb = false;
@FXML
private Button hyp;
@FXML
private Label display;
@FXML
private Button one, two, three, four, five, six, seven, eight, nine, zero;
@FXML
private Button add, minus, multi, divide, equals, dot;
@FXML
private Button clear, backspace;
@FXML
private Button squared, cubed, squarert;
@FXML
private Button sin, cos, tan;
@FXML
void handleButtonAction(ActionEvent event) {
if(start)
{
data = Double.parseDouble(display.getText());
start = false;
}
if(event.getSource() == one)
{
display.setText(display.getText() + "1");
}
else if(event.getSource() == two)
{
display.setText(display.getText() + "2");
}
else if(event.getSource() == three)
{
display.setText(display.getText() + "3");
}
else if(event.getSource() == four)
{
display.setText(display.getText() + "4");
}
else if(event.getSource() == five)
{
display.setText(display.getText() + "5");
}
else if(event.getSource() == six)
{
display.setText(display.getText() + "6");
}
else if(event.getSource() == seven)
{
display.setText(display.getText() + "7");
}
else if(event.getSource() == eight)
{
display.setText(display.getText() + "8");
}
else if(event.getSource() == nine)
{
display.setText(display.getText() + "9");
}
else if(event.getSource() == zero)
{
display.setText(display.getText() + "0");
}
else if(event.getSource() == dot)
{
display.setText(display.getText() + ".");
dot.setDisable(true);
}
else if(event.getSource() == clear)
{
display.setText("");
dot.setDisable(false);
}
else if(event.getSource() == add)
{
operation = -1; // need this line, or otherwise there will be bug
operation = 1;
data = Float.parseFloat(display.getText());
display.setText("");
dot.setDisable(false);
}
else if(event.getSource() == minus)
{
operation = -1; // need this line, or otherwise there will be bug
operation = 2;
data = Float.parseFloat(display.getText());
display.setText("");
dot.setDisable(false);
}
else if(event.getSource() == multi)
{
operation = -1;
operation = 3;
data = Float.parseFloat(display.getText());
display.setText("");
dot.setDisable(false);
}
else if(event.getSource() == divide)
{
operation = -1;
operation = 4;
data = Float.parseFloat(display.getText());
display.setText("");
dot.setDisable(false);
}
else if(event.getSource() == equals)
{
Double secondOperand = Double.parseDouble(display.getText());
dot.setDisable(false);
switch(operation)
{
case 1: //Addition
Double ans = data + secondOperand;
display.setText(String.valueOf(ans));
break;
case 2: //Subtraction
ans = data - secondOperand;
display.setText(String.valueOf(ans));
break;
case 3: //Multiplication
ans = data * secondOperand;
display.setText(String.valueOf(ans));
break;
case 4: //Division
ans = 0d;
try{
ans = data / secondOperand;
}catch(Exception ex){display.setText("Error");}
display.setText(String.valueOf(ans));
break;
}
operation = -1;
if(event.getSource() != divide && event.getSource() != add && event.getSource() != multi && event.getSource() != minus)
{
start = true;
//it works here
}
}
else if(event.getSource() == squared)
{
data = Double.parseDouble(display.getText());
Double ans = data * data;
display.setText(String.valueOf(ans));
if(event.getSource() != divide && event.getSource() != add && event.getSource() != multi && event.getSource() != minus && event.getSource() != pow && event.getSource() != mod)
{
start = true;
//but not here or the below buttons
}
}
else if(event.getSource() == cubed)
{
data = Float.parseFloat(display.getText());
Double ans = data * data * data;
display.setText(String.valueOf(ans));
dot.setDisable(false);
if(event.getSource() != divide && event.getSource() != add && event.getSource() != multi && event.getSource() != minus && event.getSource() != pow && event.getSource() != mod)
{
start = true;
}
}
else if(event.getSource() == squarert)
{
data = Float.parseFloat(display.getText());
Double ans = Math.sqrt(data);
display.setText(String.valueOf(ans));
dot.setDisable(false);
if(event.getSource() != divide && event.getSource() != add && event.getSource() != multi && event.getSource() != minus && event.getSource() != pow && event.getSource() != mod)
{
start = true;
}
}
else if(event.getSource() == backspace)
{
if (display.getText().length()>0){
StringBuffer sb = new StringBuffer(display.getText());
sb = sb.deleteCharAt(display.getText().length()-1);
display.setText(sb.toString());
}
dot.setDisable(false);
if(event.getSource() != divide && event.getSource() != add && event.getSource() != multi && event.getSource() != minus && event.getSource() != pow && event.getSource() != mod)
{
start = true;
}
}
else if(event.getSource() == sin)
{
if(hypb == true)
{
data = Float.parseFloat(display.getText());
Double ans = Math.sinh(Math.toRadians(data));
display.setText(String.valueOf(ans));
dot.setDisable(false);
}
else if(hypb == false)
{
data = Float.parseFloat(display.getText());
Double ans = Math.sin(Math.toRadians(data));
display.setText(String.valueOf(ans));
dot.setDisable(false);
}
dot.setDisable(false);
if(event.getSource() != divide && event.getSource() != add && event.getSource() != multi && event.getSource() != minus && event.getSource() != pow && event.getSource() != mod)
{
start = true;
}
}
else if(event.getSource() == cos)
{
data = Float.parseFloat(display.getText());
Double ans = Math.cos(Math.toRadians(data));
display.setText(String.valueOf(ans));
dot.setDisable(false);
if(event.getSource() != divide && event.getSource() != add && event.getSource() != multi && event.getSource() != minus && event.getSource() != pow && event.getSource() != mod)
{
start = true;
}
}
else if(event.getSource() == tan)
{
data = Float.parseFloat(display.getText());
Double ans = Math.tan(Math.toRadians(data));
display.setText(String.valueOf(ans));
dot.setDisable(false);
if(event.getSource() != divide && event.getSource() != add && event.getSource() != multi && event.getSource() != minus && event.getSource() != pow && event.getSource() != mod)
{
start = true;
}
}
//there are more buttons, I'm just not going to show them all.
}
来源：https://stackoverflow.com/questions/57100504/javafx-calculator-doesnt-clear-after-answer