Android for Beginners : Cookies Solution Code

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#B388FF"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <ImageView
        android:id="@+id/android_cookie_image_view"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:scaleType="centerCrop"
        android:src="@drawable/before_cookie"
        android:text="@string/hello_world" />

    <TextView
        android:id="@+id/status_text_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginRight="16dp"
        android:layout_marginTop="16dp"
        android:text="I'm so hungry"
        android:textColor="@android:color/white"
        android:textSize="34sp" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:text="Eat cookie"
        android:onClick="eatCookie" />

</LinearLayout>

MainActivity.java

package com.example.android.cookies;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;


public class MainActivity extends AppCompatActivity {

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

    /**
     * Called when the cookie should be eaten.
     */
    public void eatCookie(View view) {
        // Find a reference to the ImageView in the layout. Change the image.
        ImageView imageView = (ImageView) findViewById(R.id.android_cookie_image_view);
        imageView.setImageResource(R.drawable.after_cookie);

        // Find a reference to the TextView in the layout. Change the text.
        TextView textView = (TextView) findViewById(R.id.status_text_view);
        textView.setText("I'm so full");
    }
}

It crashes with me also ... but I could fix this by copying the images to drawable folder in project files as I found them in folder called
drawable-v24 only

my code:
activity_main.xml _________________

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#B388FF"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <ImageView
        android:id="@+id/android_cookie_image_view"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:scaleType="centerCrop"
        android:src="@drawable/before_cookie" />

    <TextView
        android:id="@+id/status_text_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginRight="16dp"
        android:layout_marginTop="16dp"
        android:text="I'm so hungry"
        android:textColor="@android:color/white"
        android:textSize="34sp" />

    <Button
        android:id="@+id/eat_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:onClick="eatCookie"
        android:text="EAT COOKIE" />

</LinearLayout>

MainActivity.java _________________

package com.example.android.cookies;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;


public class MainActivity extends AppCompatActivity {

    protected boolean toEat = true;

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

    /**
     * Changes message on textView
     */
    private void displayMessage(String message) {
        TextView statusTextView = findViewById(R.id.status_text_view);
        statusTextView.setText(message);
    }

    /**
     * Changes button text
     */
    private void displayButtonText(String text) {
        Button eatButton = findViewById(R.id.eat_button);
        eatButton.setText(text);
    }

    /**
     * Changes image
     */
    private void displayImage(int img) {
        ImageView androidCookieImageView = findViewById(R.id.android_cookie_image_view);
        androidCookieImageView.setImageResource(img);
        androidCookieImageView.setImageResource(img);
    }

    /**
     * Called when button eat_button is pressed
     */
    public void eatCookie(View view) {
        //if toEat is true, eat like it was the last meal
        if (toEat) {
            displayImage(R.drawable.after_cookie);
            displayMessage("I'm so full"); //show some regret
            displayButtonText("Eat another Cookie!"); //suppress the regret

            toEat = false; //not to eat anymore
        } else {
            //if toEat is false, allow eat another cookie
            displayImage(R.drawable.before_cookie);
            displayMessage("Well, aways has space for some more :P"); //make a banal excuse
            displayButtonText("Eat the Cookie"); //Test your limits

            toEat = true; //to eat
        }
    }
}

I succeeded !

ok done

you will notice that i didn't cast my objects view and it works.....but i don't know why it doesn't matter?!!!!

I don't know about anyone else, but I had to escape the single quote in "I'm so full". Note, I used the strings.xml resource file to hold the string value. Here's my eatCookie() method

public void eatCookie(View view) {
ImageView changeImage = (ImageView) findViewById(R.id.android_cookie_image_view);
changeImage.setImageResource(R.drawable.after_cookie);

    TextView changeText = (TextView) findViewById(R.id.status_text_view);
    changeText.setText(R.string.sofull);

}

and the strings.xml file:

< resources >
< string name="app_name" >Cookies< /string >
< string name="sofull" >I \ 'm so full!< /string >
< /resources >

Also, I did not need to add anything to my gradle.build app file. There were errors when I added it, and with many things in this course, that code was obsolete for my version. (Android Studio 3.4.1). So, I skipped that step.

well Done

Can anybody help me? How to resolve these errors?