Android与MVC设计模式相关操作

1.创建新类
打开工具栏，点击File，New，在选择java Class，然后再进行相应的设置。

Question.Java代码及截图如下

package com.example.a04_d3_b0_20_18_ea07_2;

public class Question {
    private int mTextResId;
    private boolean mAnswerTrue;

    public boolean isAnswerTrue() {
        return mAnswerTrue;
    }

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

    public int getTextResId() {
        return mTextResId;
    }

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

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

方法二，运用生成getter方法和setter方法
操作：File——Setting，依次展开Editor和Code Style选项，在Java选项下选择Code Generation选项，添加如下内容。


2.Android 与 MVC 设计模式及更新新图层
对activity_main.xml进行操作
完整代码如下：

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

</LinearLayout>

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

    </LinearLayout>
对string.XML进行操作代码如下：

```bash
<resources>
    <string name="app_name">04-d3-b0-20-18-EA 07-2</string>
    <string name="question_australia">Ganberra 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="incorrect_toast">Incorrect!</string>
    <string name="next_button">NEXT</string>
</resources>

3.更新控制层
对MainActivity.Java进行修改

完整代码如下：

package com.example.a04_d3_b0_20_18_ea07_2;

import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity extends AppCompatActivity {
    private Button mTrueButton;
    private Button mFalseButton;
    private Button mNextButton;
    private TextView mQuestionTextView;

    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_main);
        mQuestionTextView = (TextView) findViewById(R.id.question_text_view);

        mTrueButton = (Button) findViewById(R.id.true_button);
        mTrueButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                checkAnsewer(true);
            }
        });

        mFalseButton = (Button) findViewById(R.id.false_button);
        mFalseButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                checkAnsewer(false);
            }
        });
        mNextButton = (Button) findViewById(R.id.next_button);
        mNextButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mCurrentIndex = (mCurrentIndex + 1) % mQuestionBank.length;

                updateQuestion();
            }
        });
        updateQuestion();
    }
    private void updateQuestion() {
        int question = mQuestionBank[mCurrentIndex].getTextResId();
        mQuestionTextView.setText(question);
    }
    private void checkAnsewer(boolean userPressedTrue) {
        boolean answerIsTrue = mQuestionBank[mCurrentIndex].isAnswerTrue();

        int messageResId = 0;

        if (userPressedTrue == answerIsTrue) {
            messageResId = R.string.correct_toast;
        } else {
            messageResId = R.string.incorrect_toast;
        }
        Toast.makeText(this,messageResId, Toast.LENGTH_SHORT).show();
    }
}

4.模拟机测试
按下NEXT按钮就会改变输出
如下：






5.手机测试
测试结果和模拟机一样