第一个项目《Android编程权威指南》

activity_cheat.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:orientation="vertical"
    android:gravity="center"
    tools:context="com.example.unubtu.geoquiz.CheatActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="24dp"
        android:text="@string/warning_text"/>

    <TextView
        android:id="@+id/answer_text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="24dp"
        tools:text="Answer"/>

    <Button
        android:id="@+id/show_answer_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/show_answer_button"/>

</LinearLayout>

activity_quiz.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical">
    <TextView
        android:id="@+id/question_text-view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:padding="24dp"/>
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <Button
            android:id="@+id/true_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/true_button"/>
        <Button
            android:id="@+id/false_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/false_button"/>
        <Button
            android:id="@+id/cheat_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/cheat_button"/>
        <Button
            android:id="@+id/next_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/next_button"
            android:drawableRight="@drawable/arrow_right"
            android:drawablePadding="4dp"/>
    </LinearLayout>
</LinearLayout>

 activity_quiz.xml(land)

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >
    <TextView
        android:id="@+id/question_text-view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:padding="24dp"/>
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical|center_horizontal"
        android:orientation="horizontal">
        <Button
            android:id="@+id/true_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/true_button"/>
        <Button
            android:id="@+id/false_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/false_button"/>
        <Button
            android:id="@+id/cheat_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom|center_horizontal"
            android:text="@string/cheat_button"/>
        <Button
            android:id="@+id/next_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom|right"
            android:text="@string/next_button"
            android:drawableRight="@drawable/arrow_right"
            android:drawablePadding="4dp"/>
    </LinearLayout>
</FrameLayout>

 Androidmanifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.unubtu.geoquiz">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".QuizActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".CheatActivity"></activity>
    </application>

</manifest>

 string.xml

<resources>
    <string name="app_name">GeoQuiz</string>
    <string name="question_australia">Canberra is the capital of Australia.</string>
    <string name="question_oceans">The Pacific Ocean is larger than the Atlantic Ocean!</string>
    <string name="question_mideast">The Suez Canal connects the Red Sea and the Indian Ocean.</string>
    <string name="question_africa">The source of the Nile River is in Egypt.</string>
    <string name="question_americas">The Amazon River is the longest river in the Americas.</string>
    <string name="question_asia">Lake Baikal is the world\'s oldest and deepest freshwater lake.</string>
    <string name="true_button">True</string>
    <string name="false_button">False</string>
    <string name="correct_toast">Correct!</string>
    <string name="next_button">Next</string>
    <string name="incorrect_toast">Incorrect!</string>
    <string name="warning_text">Are you sure you want to do this?</string>
    <string name="show_answer_button">Show Answer</string>
    <string name="cheat_button">Cheat!</string>
    <string name="judgement_toast">Cheating is wrong.</string>
</resources>

 QuizActivity.java

package com.example.unubtu.geoquiz;

import android.app.Activity;
import android.content.Intent;
import android.os.PersistableBundle;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class QuizActivity extends AppCompatActivity {

    private static final String KEY_INDEX = "index";

    private Button mTrueButton;
    private Button mFalseButton;
    private Button mNextButton;
    private Button mCheatButton;
    private boolean mIsCheater;
    private TextView mQuestionTextView;

    private static final int REQUEST_CODE_CHEAT = 0;

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt(KEY_INDEX, mCurrentIndex);
    }

    private Question[] mQuestionBank =new Question[] {
            new Question(R.string.question_australia, true),
            new Question(R.string.question_oceans,true),
            new Question(R.string.question_mideast,false),
            new Question(R.string.question_africa,false),
            new Question(R.string.question_americas,true),
            new Question(R.string.question_asia,true)
    };

    private int mCurrentIndex = 0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_quiz);

        if (savedInstanceState != null) {
            mCurrentIndex = savedInstanceState.getInt(KEY_INDEX, 0);
        }

        mQuestionTextView = (TextView) findViewById(R.id.question_text_view);
        int question = mQuestionBank[mCurrentIndex].getTextResId();
        mQuestionTextView.setText(question);

        mTrueButton = (Button) findViewById(R.id.true_button);
        mTrueButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //Toast.makeText(QuizActivity.this, R.string.correct_toast, Toast.LENGTH_SHORT).show();
                checkAnswer(true);
            }
        });

        mFalseButton = (Button) findViewById(R.id.false_button);
        mFalseButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //Toast.makeText(QuizActivity.this,R.string.incorrect_toast,Toast.LENGTH_SHORT).show();
                checkAnswer(false);
            }
        });

        mNextButton = (Button) findViewById(R.id.next_button);
        mNextButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mCurrentIndex = (mCurrentIndex + 1) % mQuestionBank.length;
                mIsCheater = false;
                int question = mQuestionBank[mCurrentIndex].getTextResId();
                mQuestionTextView.setText(question);
            }
        });

        mCheatButton = (Button)findViewById(R.id.cheat_button);
        mCheatButton.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View view) {
                boolean answerIsTrue = mQuestionBank[mCurrentIndex].isAnswerTrue();
                Intent intent = CheatActivity.newIntent(QuizActivity.this, answerIsTrue);
                startActivityForResult(intent, REQUEST_CODE_CHEAT);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (resultCode != Activity.RESULT_OK) {
            return;
        }

        if (requestCode == REQUEST_CODE_CHEAT) {
            if (data == null) {
                return;
            }
            mIsCheater = CheatActivity.wasAnswerShown(data);
        }
    }

    private  void checkAnswer(boolean userPressTrue) {
        boolean answerIsTrue = mQuestionBank[mCurrentIndex].isAnswerTrue();
        int messageResId = 0;

        if (mIsCheater) {
            messageResId = R.string.judgement_toast;
        } else {
            if (userPressTrue == answerIsTrue) {
                messageResId = R.string.correct_toast;
            } else {
                messageResId = R.string.incorrect_toast;
            }
        }

        Toast.makeText(this,messageResId,Toast.LENGTH_SHORT).show();
    }
}

Question.java

package com.example.unubtu.geoquiz;

/**
 * Created by unubtu on 18-3-21.
 */

public class Question {
    private int mTextResId;
    private boolean mAnswerTrue;
    public Question(int textResId, boolean answerTrue) {
        mTextResId = textResId;
        mAnswerTrue = answerTrue;
    }

    public int getTextResId() {
        return mTextResId;
    }
    public void setTextResId(int textResId) {
        mTextResId = textResId;
    }

    public  boolean isAnswerTrue()  {
        return mAnswerTrue;
    }
    public void setAnswerTrue(boolean answerTrue){
        mAnswerTrue = answerTrue;
    }
}

 CheatActivity.java

package com.example.unubtu.geoquiz;

import android.content.Context;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class CheatActivity extends AppCompatActivity {

    private static final String EXTRA_ANSWER_IS_TRUE = "com.example.unubtu.geoquiz.answer_is_true";
    private static final String EXTRA_ANSWER_SHOWN = "com.example.unubtu.geoquiz.answershown";
    private boolean mAnswerIsTrue;

    private TextView mAnswerTextView;
    private Button mShowAnswerButton;


    public static Intent newIntent(Context packageContext, boolean answerIsTrue) {
        Intent intent = new Intent(packageContext, CheatActivity.class);
        intent.putExtra(EXTRA_ANSWER_IS_TRUE, answerIsTrue);
        return intent;
    }

    public static boolean wasAnswerShown(Intent result) {
        return result.getBooleanExtra(EXTRA_ANSWER_SHOWN, false);
    }

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

        mAnswerIsTrue = getIntent().getBooleanExtra(EXTRA_ANSWER_IS_TRUE, false);

        mAnswerTextView = (TextView) findViewById(R.id.answer_text_view);

        mShowAnswerButton = (Button) findViewById(R.id.show_answer_button);
        mShowAnswerButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if(mAnswerIsTrue) {
                    mAnswerTextView.setText(R.string.true_button);
                } else {
                    mAnswerTextView.setText(R.string.false_button);
                }
                setAnswerShownResult(true);
            }
        });
    }

    private void setAnswerShownResult(boolean isAnswerShown) {
        Intent data = new Intent();
        data.putExtra(EXTRA_ANSWER_SHOWN, isAnswerShown);
        setResult(RESULT_OK, data);
    }
}

效果：