Problem z kalkulatorem na androida

Question

Witam, robię bardzo prosty kalkulator na androida. Mam problem, po kliknieciu znaku "=" równa się. Cały program się zatrzymuje. Czy ktos wie czym to może być spowodowane? Problem wsytępuje po kliknięciu Buttona 

buttonEqual

package com.example.project1;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class Kalkulator extends AppCompatActivity {

    double input1 = 0, input2 = 0;
    boolean Addition, Subtract, Multiplication, decimal;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_kalkulator);

        setTitle("Kalkulator");

        Button button0 = findViewById(R.id.button_zero);
        Button button1 = findViewById(R.id.button_one);
        Button button2 = findViewById(R.id.button_two);
        Button button3 = findViewById(R.id.button_three);
        Button button4 = findViewById(R.id.button_four);
        Button button5 = findViewById(R.id.button_five);
        Button button6 = findViewById(R.id.button_six);
        Button button7 = findViewById(R.id.button_seven);
        Button button8 = findViewById(R.id.button_eight);
        Button button9 = findViewById(R.id.button_nine);

        Button button_multiplication = findViewById(R.id.button_multiplication);
        Button button_subtraction = findViewById(R.id.button_subtraction);
        Button button_addition = findViewById(R.id.button_addition);

        final TextView displayNum = findViewById(R.id.textView_input_numbers);
        Button buttonEqual = findViewById(R.id.button_equal);
        Button button_clear = findViewById(R.id.button_clear);

        button0.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                displayNum.setText(displayNum.getText()+"0");
            }
        });

        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                displayNum.setText(displayNum.getText()+"1");
            }
        });

        button2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                displayNum.setText(displayNum.getText()+"2");
            }
        });

        button3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                displayNum.setText(displayNum.getText()+"3");
            }
        });

        button4.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                displayNum.setText(displayNum.getText()+"4");
            }
        });

        button5.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                displayNum.setText(displayNum.getText()+"5");
            }
        });

        button6.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                displayNum.setText(displayNum.getText()+"6");
            }
        });

        button7.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                displayNum.setText(displayNum.getText()+"7");
            }
        });

        button8.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                displayNum.setText(displayNum.getText()+"8");
            }
        });


        button9.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                displayNum.setText(displayNum.getText()+"9");
            }
        });


        button_multiplication.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(displayNum.getText().length() !=0){
                    input1 = Float.parseFloat(displayNum.getText()+"");
                    Multiplication = true;
                    decimal = false;
                    displayNum.setText(null);
                }
            }
        });

        button_subtraction.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(displayNum.getText().length() !=0){
                    input1 = Float.parseFloat(displayNum.getText()+"");
                    Subtract = true;
                    decimal = false;
                    displayNum.setText(null);
                }
            }
        });

        button_addition.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(displayNum.getText().length() !=0){
                    input1 = Float.parseFloat(displayNum.getText()+"");
                    Addition = true;
                    decimal = false;
                    displayNum.setText(null);
                }
            }
        });


        buttonEqual.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(Addition || Subtract || Multiplication){
                    input2 = Float.parseFloat(displayNum.getText() + "");
                }
                if(Addition){
                    displayNum.setText(input1 + input2 + "");
                    Addition = false;
                }
                if (Subtract) {

                    displayNum.setText(input1 - input2 + "");
                    Subtract = false;
                }
                if (Multiplication) {
                    displayNum.setText(input1 * input2 + "");
                    Multiplication = false;
                }

            }
        });


        button_clear.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                displayNum.setText("");
                input1 = 0.0;
                input2 = 0.0;
            }
        });


    }
}

 

Comments

Dlaczego robisz displayNum.setText(null) zamiast .setText("") albo .setText("0")?