Android项目开发— GeoQuiz

GeoQuiz项目的开发过程

首先，创建Androi项目，接着就是完成用户界面的设计。

1.用户界面设计

.在activity_quiz.xml中定义组件

<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/cheat_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/cheat_button"/>
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <Button
            android:id="@+id/pre_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/pre_button"
            android:drawableLeft="@drawable/arrow_left"/>
        <ImageButton
            android:id="@+id/next_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/arrow_right"
            android:contentDescription="@string/next_button"/>
    </LinearLayout>
</LinearLayout>

2.组件的应用

.引用组件

private Button mTrueButton;//在activity_quiz.java添加成员变量
    private Button mTrueButton;
    private Button mFalseBuyton;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_quiz);

        mTrueButton = (Button) findViewById(R.id.true_button);
        mFalseButton = (Button) findViewById(R.id.false_button);
    }

.设置监听器

private Button mTrueButton;//在activity_quiz.java添加成员变量
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        ......
         mTrueButton=(Button)findViewById(R.id.true_button);//引用组件
         mTrueButton.setOnClickListener(new View.OnClickListener(){

            @Override
            public void onClick(View v) {
                //设置监听事件
            }
        });
    }

３．创建提示消息

.在strings.xml中增加toast字符串

<string name="true_button">True</string>
    <string name="false_button">False</string>
    <string name="next_button">Next</string>

    <string name="correct_toast">Correct</string>
    <string name="incorrect_toast">Incorrect</string>

.创建提示消息

//举个例子来说
Toast.makeText(QuizActivity.this,R.string.incorrect_toast,Toast.LENGTH_SHORT).show();

4.Android 与 MVC设计模式

.Question类中的代码,

package com.example.cyk.aclass;

/**
 * Created by cyk on 2017/9/7.
 */

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 mTextResId) {
        this.mTextResId = mTextResId;
    }

    public boolean isAnswerTrue() {
        return mAnswerTrue;
    }

    public void setAnswerTrue(boolean mAnswerTrue) {
        this.mAnswerTrue = mAnswerTrue;
    }
}

.更新控制器层（QuizActivity）

public class QuizActivity extends AppCompatActivity {
    private ImageButton mNextButton;

    private TextView mQuestionTextView;

    private Question[] mQuestionBank=new Question[]{
            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;

}

5.activtity的生命周期

.日志跟踪理解activity生命周期

public static int d(String tag,String msg)//输出日志信息d:debug
方法的第一个参数通常是以类名为值的TAG常量传入

public class QuizActivity extends AppCompatActivity {
    private static final String TAG="QuizActivity";
    ......
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Log.d(TAG,"onCreate(Bundle) called");

        setContentView(R.layout.activity_quiz);

        ......
    }
}

.水平模式布局修改（layout_land/activity_quiz/xml）

注意:两个布局文件的文件名必须相同，这样它们才能以同一个资源ID被引用

<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"/>
    </LinearLayout>
    <Button
        android:id="@+id/cheat_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|center"
        android:text="@string/cheat_button"/>

    <Button
        android:id="@+id/pre_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|left"
        android:text="@string/pre_button"
        android:drawableLeft="@drawable/arrow_left"
        android:drawablePadding="4dp"/>
    <ImageButton
        android:id="@+id/next_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|right"
        android:src="@drawable/arrow_right"
        android:contentDescription="@string/next_button"/>
</FrameLayout>

6.第二个activity

.activity_cheat.xml的定义（第二个用户界面）

<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:gravity="center"
    android:orientation="vertical"
    tools:context="com.example.mdx.studyworks.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>

在manifest配置文件中声明CheatActivity

<activity android:name=".CheatActivity">
        </activity>