Android - Display Int onClick with Buttons increment , decremet [Error: Cannot resolve method ‘display(int)’ ] I am getting a error on Android Studio as what I believe is because I'm inserting multiple 'displays'. Can someone advise & explain what I need to do and why it causes this error so I know for future?

Please see below for the following error:

package com.example.justjava;

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

import androidx.appcompat.app.AppCompatActivity;

import java.text.NumberFormat;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView num = findViewById(R.id.num);
        Button order1 = findViewById(R.id.order);
        /**
         * This method is called when the plus button is clicked.
         */
        public void increment (View view) {
            int quantity = 2;
            display(quantity);
        }
        /**
         * This method is called when the minus button is clicked.
         */
        public void onClick (View view) {
            int quantity = 2;
            display(quantity);
        }


        /**
         * This method is called when the order button is clicked.
         */
        order1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                int quantity = 2;
                display1(quantity);
                displayPrice(quantity*5);
            }

            /**
             * This method displays the given price on the screen.
             */
            private void displayPrice(int number) {
                TextView priceTextView = (TextView) findViewById(R.id.price_text_view);
                priceTextView.setText(NumberFormat.getCurrencyInstance().format(number));
            }
            /**
             * This method displays the given quantity value on the screen.
             */
            private void display1(int number)
            {
                //  TextView quantity = (TextView) findViewById(R.id.quantity);
                num.setText(""   number);
            }


        });
    }
}

CodePudding user response：

In Java, we don't have anything called Local Function as a result, move the functions from the onCreate method to the class.

CodePudding user response：

Firstly, implement your methods onClick() and increment() outside of the function onCreate(). It does not make sense to implement a function inside of a fuction. You can implement them inside the class MainActivity. Moreover, I would suggest not to name your custom button click function as onClick() as it might lead to confusion later on.

Secondly, I cannot see the implementation of the function "display()". That's why AndroidStudio cannot recognize the function. If you move onClick() and increment() to the place I said and in the same class implement the display function, it should be fine.