达内课程-面向对象简介

类

对事物、算法、逻辑、概念的抽象

相关的属性数据、运算方法封装在一个类组件中

对象（实例）

理解成从图纸生产的产品

每个对象占用独立的内存空间，保存各自的属性数据

每个对象可以独立控制，让它执行指定的方法代码

引用

理解成遥控器

引用变量中保存一个对象的内存地址，通过引用变量可以找到对象的内存空间，访问它的属性数据，或控制它执行方法

Soldier类

public class Soldier {
//成员变量
int id;//默认0
int blood = 100;
//成员方法
public void go(TextView tv){
tv.setText(id+"前进"+"\n"+tv.getText());
}
public void attack(TextView tv){
if(blood == 0){
tv.setText("这是"+id+"号士兵的尸体"+"\n"+tv.getText());
return;
}

tv.setText(id+"号士兵进攻"+"\n"+tv.getText());
int b = new Random().nextInt(10);
if(blood<b){
blood = b;
}
blood -= b;
if(blood == 0){
tv.setText(id+"号士兵阵亡"+"\n"+tv.getText());
}
}
}

MainActivity

public class MainActivity extends AppCompatActivity {
TextView textView;
Soldier s1;//默认null
Soldier s2;//默认null

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

public void doClick(View view) {
textView = (TextView) findViewById(R.id.textView);
switch (view.getId()) {
case R.id.button1:

4000
f1();
break;
case R.id.button2:
f2();
break;
case R.id.button3:
f3();
break;
}
}

public void f1(){
s1 = new Soldier();
s1.id = 9527;
//用s1找到士兵对象内存空间
//访问它的属性变量id
textView.setText("士兵9527已创建"+"\n");
}
public void f2(){
s1.go(textView);
}

public void f3(){
s1.attack(textView);
textView.setText("士兵"+s1.id+"血量"+s1.blood+"\n"+textView.getText());
}
}

xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical">

<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="新建士兵1"
android:onClick="doClick"/>
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="前进"
android:onClick="doClick"/>
<Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="进攻"
android:onClick="doClick"/>

<Button
android:id="@+id/button4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="新建士兵2"
android:onClick="doClick"/>
<Button
android:id="@+id/button5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="前进"
android:onClick="doClick"/>
<Button
android:id="@+id/button6"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="进攻"
android:onClick="doClick"/>

<TextView
android:id="@+id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</LinearLayout>

FlashLight类

xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:id="@+id/layout"
android:background="@android:color/black">

<ToggleButton
android:id="@+id/toggleButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textOn="开"
android:textOff="关"
android:onClick="doClick"
/>
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="红"
android:onClick="doClick"/>
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="白"
android:onClick="doClick"/>
<Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="蓝"
android:onClick="doClick"/>

</LinearLayout>

FlashLight.java

public class FlashLight {
//属性变量，成员变量
int color = Color.BLACK;
boolean on = false;

public void turnOn(){
on = true;
}

public void turnOff(){
on = false;
}
}

MainActivity.java

public class MainActivity extends AppCompatActivity {
FlashLight flashLight = new FlashLight();
LinearLayout linearLayout;
ToggleButton toggleButton;

Button red;
Button white;
Button blue;

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

linearLayout = (LinearLayout) findViewById(R.id.layout);
toggleButton = (ToggleButton)findViewById(R.id.toggleButton);
red = (Button) findViewById(R.id.button1);
white = (Button)findViewById(R.id.button2);
blue = (Button)findViewById(R.id.button3);

}

public void doClick(View view) {
switch (view.getId()) {
case R.id.button1:
f1();
break;
case R.id.button2:
f2();
break;
case R.id.button3:
f3();
break;
case R.id.toggleButton:
f4();
break;
}
}

public void f1(){
//用light变量找到手电筒对象的内存空间地址
//访问它的color变量
flashLight.color = Color.RED;
show();
}
public void f2(){
flashLight.color = Color.WHITE;
show();
}

public void f3(){
flashLight.color = Color.BLUE;
show();
}

public void f4(){
//判断开关指示按钮状态

if(toggleButton.isChecked()){
flashLight.turnOn();
}else{
flashLight.turnOff();
}
show();
}

public void show(){
//根据flashlight属性控制界面
if(flashLight.on){
linearLayout.setBackgroundColor(flashLight.color);
}else{
linearLayout.setBackgroundColor(Color.BLACK);
}
}
}

汽车类

Car.java

public class Car {
public String color;
public String brand;
public int speed;

public void go(TextView tv){
tv.append("\n"+color+brand+"汽车以时速"+speed+"前进");
}
public void stop(TextView tv){
tv.append("\n"+color+brand+"汽车停止");
}
}

xml

<?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:columnCount="4"
android:orientation="vertical"
android:rowCount="6">

<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="创建汽车"
android:onClick="doClick"
/>

<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="go"
android:onClick="doClick"/>

<Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
<
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span class="hljs-attribute">android:text="stop"
android:onClick="doClick"/>

<TextView
android:id="@+id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>

</LinearLayout>

MainActivity

public class MainActivity extends AppCompatActivity {
Car car;

Button create;
Button go;
Button stop;
TextView textView;

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

create = (Button)findViewById(R.id.button1);
go = (Button)findViewById(R.id.button2);
stop = (Button)findViewById(R.id.button3);
textView = (TextView)findViewById(R.id.textView);
}

public void doClick(View view) {
switch (view.getId()) {
case R.id.button1:
f1();
break;
case R.id.button2:
f2();
break;
case R.id.button3:
f3();
break;
}
}

private void f1(){
car = new Car();
//默认值如下
//color="";
//brand="";
//speed=0;
car.color = "红色";
car.brand="BMW";
car.speed=80;
textView.setText("汽车已创建");
}

private void f2(){
car.go(textView);
}
private void f3(){
car.stop(textView);
}
}

宠物狗类

Dog

public class Dog {
public String name;//名字
public int hungry;//饥饿度
public int happy;//快乐度

//喂食
public void feed(TextView textView){
if(hungry==0){
textView.setText(name+"吃饱了\n"+textView.getText());
return;
}
hungry-=10;
textView.setText("给"+name+"喂食,hungry:"+hungry+"\n"+textView.getText());
}
//玩
public void play(TextView textView){
if(hungry == 100){
textView.setText(name+"很俄了\n"+textView.getText());
return;
}
happy+=10;
hungry+=10;

textView.setText("陪"+name+"玩耍,happy:"+happy+",hungry:"+hungry+"\n"+textView.getText());
}
//惩罚
public void punish(TextView textView){
happy-=10;
textView.setText("打"+name+"的pp,"+name+"哭叫:汪,happy"+happy+"\n"+ textView.getText());
}
}

xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:columnCount="4"
android:orientation="vertical"
android:rowCount="6">

<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="创建宠物狗"
android:onClick="doClick"
/>

<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="play"
android:onClick="doClick"/>

<Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="feed"
android:onClick="doClick"/>

<Button
android:id="@+id/button4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="punish"
android:onClick="doClick"/>

<TextView
android:id="@+id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>

</LinearLayout>

MainActivity

public class MainActivity extends AppCompatActivity {
Dog dog;

Button create;
Button play;
Button feed;
Button punish;
TextView textView;

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

create = (Button)findViewById(R.id.button1);
play = (Button)findViewById(R.id.button2);
feed = (Button)findViewById(R.id.button3);
punish = (Button)findViewById(R.id.button4);
textView = (TextView)findViewById(R.id.textView);
}

public void doClick(View view) {
switch (view.getId()) {
case R.id.button1:
f1();
break;
case R.id.button2:
f2();
break;
case R.id.button3:
f3();
break;
case R.id.button4:
f4();
break;
}
}

private void f1(){
dog = new Dog();
dog.name = "蠢狗";
dog.hungry = 50;
dog.happy = 50;

textView.setText("电子狗已经创建");
}

private void f2(){
dog.play(textView);
}
private void f3(){
dog.feed(textView);
}
private void f4(){
dog.punish(textView);
}
}