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Android Build an Interactive Story App Finishing the User Interface Loading the First Page

Mihai Mesteru
Mihai Mesteru
6,449 Points
Posted by Mihai Mesteru
Mihai Mesteru
6,449 Points

Can't run the next page due to an R.java error?

I can't proceed to the next screen - will just show a blank screen. When I run the code, I get this error:

Error:(35, 50) error: cannot find symbol variable choice1Button

This is the code to the StoryActivity.java

package com.misi.interactivestory.ui;

import android.content.Intent;
import android.graphics.drawable.Drawable;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;


import com.misi.interactivestory.R;
import com.misi.interactivestory.model.Page;
import com.misi.interactivestory.model.Story;

public class StoryActivity extends AppCompatActivity {

    public static final String TAG = StoryActivity.class.getSimpleName();

    private Story story;
    private ImageView storyImageView;
    private TextView storyTextView;
    private Button choice1Button;
    private Button choice2Button;

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

        storyImageView = (ImageView)findViewById(R.id.storyImageView);
        storyTextView = (TextView)findViewById(R.id.storyTextView);
        choice1Button = (Button)findViewById(R.id.choice1Button);
        choice2Button = (Button)findViewById(R.id.choice2Button);

        // get the intent used to start this activity

        Intent intent = getIntent();
        String name = intent.getStringExtra(getString(R.string.key_name));
        if (name == null || name.isEmpty()) {
            name = "Friend";
        }
        Log.d(TAG, name);

        story = new Story();
        loadPage(0);


    }

    private void loadPage(int pageNumber) {
        Page page = story.getPage(pageNumber);

        Drawable image = ContextCompat.getDrawable(this, page.getImageId());
        storyImageView.setImageDrawable(image);

    }
}

If I could get an y help, that would be great. Thanks!

[MOD: edited code block - srh]

3 Answers

Steve Hunter
Steve Hunter
57,712 Points

OK - I'm not at my computer but I can see your code. Your xml does not have a button called choice1Button.

Remember, the Java variable name is separate to the layout name.

You link Java to the layout by assigning a member variable to a xml id.

You need to have a xml id called choice1Button or change your Java to the button id you have already.

Let me know how you get on.

Steve.

Mihai Mesteru
Mihai Mesteru
6,449 Points
Mihai Mesteru
Mihai Mesteru
6,449 Points

That worked - just had to go into the XML and change "@+id/button2" to "choice1button".

Thanks for the help! :)

Steve Hunter
Steve Hunter
57,712 Points
Steve Hunter
Steve Hunter
57,712 Points

Can you post your XML for the layout, please? If you're getting an R.id issue, it may think that one of your buttons is mis-named in the XML.

Steve.

Mihai Mesteru
Mihai Mesteru
6,449 Points
Mihai Mesteru
Mihai Mesteru
6,449 Points

For the Main Activity:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.misi.interactivestory.ui.MainActivity">

    <ImageView
        android:contentDescription="@string/signals_from_mars_title_image"
        android:id="@+id/titleimageView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginLeft="0dp"
        android:layout_marginRight="0dp"
        android:adjustViewBounds="true"
        android:scaleType="fitXY"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:srcCompat="@drawable/main_title"
        app:layout_constraintTop_toTopOf="parent"
        android:layout_marginTop="0dp"/>

    <Button
        android:id="@+id/startButton"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginBottom="0dp"
        android:layout_marginLeft="0dp"
        android:layout_marginRight="0dp"
        android:background="@android:color/white"
        android:text="@string/start_your_adventure"
        android:textColor="#3A8AEC"
        android:textSize="16sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"/>

    <EditText
        android:id="@+id/nameEditText"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginBottom="0dp"
        android:layout_marginLeft="0dp"
        android:layout_marginRight="0dp"
        android:background="@android:color/white"
        android:ems="10"
        android:hint="@string/enter_your_name"
        android:includeFontPadding="true"
        android:inputType="textPersonName"
        android:maxLength="30"
        app:layout_constraintBottom_toTopOf="@+id/startButton"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"/>

</android.support.constraint.ConstraintLayout>

For the Story Activity:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.misi.interactivestory.ui.StoryActivity">

    <Button
        android:id="@+id/choice2Button"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:background="@android:color/white"
        android:textColor="#3a8aec"
        android:textSize="16sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        tools:text="@string/page0_choice2"/>

    <Button
        android:id="@+id/button2"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:background="@android:color/white"
        android:textColor="#3A8AEC"
        android:textSize="16sp"
        app:layout_constraintBottom_toTopOf="@+id/choice2Button"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        tools:text="@string/page0_choice1"/>

    <ScrollView
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        android:background="@android:color/white"
        android:fillViewport="true"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <ImageView
                android:contentDescription="@string/story_image_content_description"
                android:id="@+id/storyImageView"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:adjustViewBounds="true"
                android:scaleType="fitXY"
                tools:src="@drawable/page0"/>

            <TextView
                android:id="@+id/storyTextView"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginEnd="16dp"
                android:layout_marginLeft="16dp"
                android:layout_marginRight="16dp"
                android:layout_marginStart="16dp"
                android:layout_marginTop="16dp"
                android:lineSpacingExtra="8sp"
                android:textSize="16sp"
                tools:text="@string/page0"/>
        </LinearLayout>
    </ScrollView>
</android.support.constraint.ConstraintLayout>