第一个Android程序 -- HelloAndroid

第一个Android程序 – HelloAndroid

该程序为题库问答题框架

图视层 – activity_hello_android

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="24dp"
android:orientation="vertical">

<TextView
android:id="@+id/question_text_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:padding="24dp"/>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="24dp"
android:gravity="center_horizontal"
android:orientation="horizontal">

<Button
android:id="@+id/true_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="24dp" />

<Button
android:id="@+id/false_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="24dp"/>
</LinearLayout>
<Button
android:id="@+id/next_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:padding="24dp" />
</LinearLayout>

控制层 – HelloAndroidActivity

package com.example.helloandroid;

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

public class HelloAndroidActivity extends Activity {

private Button b1;
private Button b2;
private Button nb;
private TextView qtv;
//设置三个按钮变量，一个文本变量

private TrueFalse[] qBank = new TrueFalse[]{
new TrueFalse(R.string.question1,true),
//TrueFalse包含两个参数，调用构造函数
new TrueFalse(R.string.question2,false),
new TrueFalse(R.string.question3,true),
new TrueFalse(R.string.question4,false),
};//设置TrueFalse对象数组

private int currentIndex=0;
//计数变量

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_hello_android);
//调用名为activity_hello_android的layout的用户界面

qtv = (TextView) findViewById(R.id.question_text_view);
//找到id为这个的文本id资源
int question = qBank[currentIndex].getQuestion();
//找到当前问题的文本string资源的id
qtv.setText(question);
//将数组中的问题显示到qtv上

b1 = (Button) findViewById(R.id.true_button);
b1.setText(R.string.true_button);
b1.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
//Toast.makeText(HelloAndroidActivity.this,R.string.correct_toast,Toast.LENGTH_SHORT).show();
/*toast为弹窗消息，生成一个toast用Toast.makeText，三个参数
1.Activity的一个实例
2.toast的string资源id
3.显示时间
Toast.show()显示在屏幕上
*/
checkAnswer(true);
}
});

b2 = (Button) findViewById(R.id.false_button);
b2.setText(R.string.false_button);
b2.setOnClickListener(new View.OnClickListener() {
//设置button2的监听器
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
checkAnswer(false);

4000
}
});

nb = (Button) findViewById(R.id.next_button);
nb.setText(R.string.next_button);
//next按钮显示NEXT
nb.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
currentIndex = (currentIndex+1)%qBank.length;
//当前索引先加1
int question = qBank[currentIndex].getQuestion();
//找到当前问题的文本string资源的id
qtv.setText(question);
//将数组中的问题显示到qtv上
}
});
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.hello_android, menu);
return true;
}

private void checkAnswer(boolean userA){
//判断答案是否正确，参数为用户答案
boolean currans = qBank[currentIndex].isTruequestion();
//currans为正确答案
int maessageId = 0;
//maessageId设置toast的string资源id
if(userA == currans){
//如果正确
maessageId = R.string.correct_toast;
}
else{
maessageId = R.string.incorrect_toast;
}

Toast.makeText(this, maessageId, Toast.LENGTH_SHORT).show();
//显示提示信息
}

}

模型层 – TrueFalse

package com.example.helloandroid;

public class TrueFalse {

private int question;//保存问题的string资源ID
private boolean truequestion;//判断是否正确
public TrueFalse(int qt,boolean tqt)
{//带参数的构造函数
question=qt;
truequestion=tqt;
}
public int getQuestion() {
return question;
}
public void setQuestion(int question) {
this.question = question;
}
public boolean isTruequestion() {
return truequestion;
}
public void setTruequestion(boolean truequestion) {
this.truequestion = truequestion;
}

}

R.java自动生成

字符串资源 – string.xml

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

<string name="app_name">HelloAndroid</string>
<string name="action_settings">Settings</string>
<string name="correct_toast">Correct!!!</string>
<string name="incorrect_toast">Incorrect!!!</string>
<string name="true_button">是</string>
<string name="false_button">否</string>
<string name="next_button">NEXT</string>

<string name="question1">第1个是不是show in English</string>
<string name="question2">第2个是不是show in English,不是</string>
<string name="question3">第3个是不是show in English</string>
<string name="question4">第4个是不是show in English,不是</string>
</resources>