旧版本的 Android Studio 项目无法编译 - 缺少变量声明

Question

compilation errors gradle updated

My teacher on uni gave me code to an app and my task is to add some funcionalities. The teacher claims that code is working, that there were no errors (that I do not need to fix the code, only update some older elements so that it works).

However, it doesn't compile. I updated gradle (this was the first error). And now, there are a few errors: "error: cannot find symbol variable label_rightAnswers", "error: cannot find symbol variable failed_level" etc. I thought that you may have occurred sth like this as well and you know if this is really lack of variabes' declaration or for example too old library, version of platform -tools idk. I cant find anything useful in the internet:( When i comment these lines, there are no mistakes, the emulator starts to run but the app is not displayed.

Please let me know if you have any idea what this is all about. Thanks a lot!

---

part of code provoking errors:

public class EndActivity extends Activity {

    //@SuppressLint("SetTextI18n")
    @SuppressLint("SetTextI18n")
    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_end);

        Bundle extras = getIntent().getExtras();
        boolean pass = extras.getBoolean("PASS");

        if (pass) {
            passLevel();
        } else {
            failLevel();
        }

//        txt.setTextSize(TypedValue.COMPLEX_UNIT_PX, 100);

        int wrongAnswers = extras.getInt("WRONG");
        int rightAnswers = extras.getInt("RIGHT");
        int timeout = extras.getInt("TIMEOUT");
        TextView right = (TextView) findViewById(R.id.rightAnswers);
        right.setTextSize(TypedValue.COMPLEX_UNIT_PX, 50);
        //int label_rightAnswers = 0;
        //int label_wrongAnswers = 0;
        //int label_timeout = 0;


        right.setText(getResources().getString(label_rightAnswers) + " " + rightAnswers);
        TextView wrong = (TextView) findViewById(R.id.wrongAnswers);
        wrong.setTextSize(TypedValue.COMPLEX_UNIT_PX, 50);
        wrong.setText(getResources().getString(label_wrongAnswers) + " " + wrongAnswers);

        TextView time = (TextView) findViewById(R.id.timeout);
        time.setTextSize(TypedValue.COMPLEX_UNIT_PX, 50);
        time.setText(getResources().getString(label_timeout) + " " + timeout);

    }

XML file:

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout 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="@drawable/background"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="pg.autyzm.graprzyjazneemocje.EndActivity">

    <ImageView
        android:id="@+id/sun_image_end"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:adjustViewBounds="true"
        android:src="@drawable/sun" />

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:orientation="vertical">

            android:id="@+id/rightAnswers"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="@color/score" />

        <TextView
            android:id="@+id/wrongAnswers"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="@color/score" />

        <TextView
            android:id="@+id/timeout"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="@color/score" />

    </LinearLayout>

    <!--
    <ImageButton
       android:id="@+id/exitButton"
       android:layout_width="80dp"
       android:layout_height="80dp"
       android:layout_alignParentEnd="true"
       android:layout_alignParentRight="true"
       android:layout_alignParentTop="true"
       android:background="@null"
       android:scaleType="centerCrop"
       android:src="@drawable/icon_exit" />
       -->

   <TextView
       android:id="@+id/endTextMain"
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:gravity="center_horizontal"
       android:textColor="@color/command"
       android:textSize="40dp"
       android:layout_alignParentLeft="true"
       android:layout_alignParentStart="true" />

   <ImageButton
       android:id="@+id/prevButton"
       android:layout_width="80dp"
       android:layout_height="80dp"
       android:background="@null"
       android:onClick="repeatLevel"
       android:scaleType="centerCrop"
       android:src="@drawable/icon_prev"
       android:layout_alignParentBottom="true"
       android:layout_alignParentLeft="true"
       android:layout_alignParentStart="true" />

</RelativeLayout>

Answer 1

I think these tricks will might help you.

You shouldn't be importing android.R . That should be automatically generated and recognised. if you get some error referring to R after removing the import then do as following:

Some basic steps after removing the import, if those errors appear:

• Clean your build, then rebuild
• Make sure there are no errors or typos in your XML files
• Make sure your resource names consist of [a-z0-9.] . Capitals or symbols are not allowed for some reason.
• Perform a Gradle sync (via Tools > Android > Sync Project with Gradle Files)

hope so this will help you.

Answer 2

Now try this code:-

Bundle extras = getIntent().getExtras();
    boolean pass = false;
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
        pass = Objects.requireNonNull(extras).getBoolean("PASS");
    }

    if (pass) {
        passLevel();
    } else {
        failLevel();
    }

//        txt.setTextSize(TypedValue.COMPLEX_UNIT_PX, 100);

    int wrongAnswers = extras.getInt("WRONG");
    int rightAnswers = extras.getInt("RIGHT");
    int timeout = extras.getInt("TIMEOUT");
    TextView right = (TextView) findViewById(R.id.rightAnswers);
    right.setTextSize(TypedValue.COMPLEX_UNIT_PX, 50);
    //int label_rightAnswers = 0;
    //int label_wrongAnswers = 0;
    //int label_timeout = 0;


    right.setText(getResources().getString(label_rightAnswers) + " " + rightAnswers);
    TextView wrong = (TextView) findViewById(R.id.wrongAnswers);
    wrong.setTextSize(TypedValue.COMPLEX_UNIT_PX, 50);
    wrong.setText(getResources().getString(label_wrongAnswers) + " " + wrongAnswers);

    TextView time = (TextView) findViewById(R.id.timeout);
    time.setTextSize(TypedValue.COMPLEX_UNIT_PX, 50);
    time.setText(getResources().getString(label_timeout) + " " + timeout);

I added few conditions.