装备选择案例

1.创建程序

创建一个名为“装备选择”的工程，设计用户交互界面：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>

<ImageView
android:layout_width="164dp"
android:layout_height="155dp"
android:layout_gravity="center_horizontal"
android:layout_marginTop="25dp"
android:src="@mipmap/xiaoren"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="主人，快给小宝宝买装备吧"
android:layout_gravity="center_horizontal"/>

<TableLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="25dp"
>
<TableRow
android:layout_width="match_parent"
android:layout_height="wrap_content"
>
<TextView
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent"
android:text="生命值:" />
<ProgressBar
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="0dp"
android:layout_weight="3"
android:layout_marginLeft="20dp"
android:layout_height="wrap_content"
android:id="@+id/progressBar3" />
<TextView
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent"
android:text="80"
/>
</TableRow>
<TableRow
android:layout_width="match_parent"
android:layout_height="wrap_content"
android[b]:layout_marginTop="15dp"
>
<TextView
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent"
android:text="攻擊力:" />
<ProgressBar
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="0dp"
android:layout_weight="3"
android:layout_marginLeft="20dp"
android:layout_height="wrap_content"
android:id="@+id/progressBar4" />
<TextView
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent"
android:text="200"
/>
</TableRow>
<TableRow
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="15dp"
>
<TextView
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent"
android:text="敏捷:" />
<ProgressBar
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="0dp"
android:layout_weight="3"
android:layout_marginLeft="20dp"
android:layout_height="wrap_content"
android:id="@+id/progressBar5" />
<TextView
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent"
android:text="40"
/>
</TableRow>
</TableLayout>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="10dp">

<Button
android:id="@+id/btn_master"
android:onClick="click1"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:text="主人購買裝備"
android:layout_marginTop="15dp"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />

<Button
android:id="@+id/btn_baby"
android:onClick="click2"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:text="小寶寶購買裝備"
android:layout_marginTop="15dp" />
</LinearLayout>

</LinearLayout>

布局代码中使用到了控件ProgressBar（进度条），他是用来显示人物的生命值、攻击力和敏捷度。他有两种表现形式，一种是水平的，另一种是环形的。几种常用的方法属性：

style属性：控制ProgressBar的表现形式，水平进度条需设置style的属性值为“？android：attr/ProgressBarStyleHorizontal”，环形进度条需设置的属性值为“？android：attr/ProgressBarStyleLargel”。

setMax()方法：设置进度条的最大值。

setProgress（）方法：设置当前进度。

getProgress（）：获取当前进度。

2.创建装备界面

创建装备界面activity_shop.xml，该界面是用来展示装备的，购买装备界面相应的布局文件如下：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/rl"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<View
android:layout_width="30dp"
android:layout_height="30dp"
android:background="@android:drawable/ic_menu_info_details"
android:layout_centerVertical="true"
android:layout_alignParentLeft="true"
/>
<TextView
android:id="@+id/tv_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_marginLeft="60dp"
android:text="商品名称"/>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:orientation="vertical">
<TextView
android:id="@+id/tv_1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="13sp"
android:text="生命值：" />
<TextView
android:id="@+id/tv_2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="13sp"
android:text="攻击力："
android:layout_marginTop="5dp"/>
<TextView
android:id="@+id/tv_3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="13sp"
android:text="敏    捷："
android:layout_marginTop="5dp"/>
</LinearLayout>
</RelativeLayout>

3.创建ItemInfo类

代码：

public class ItemInfo implements Serializable{
private String name;
private int life;
private int atk;
private int quick;

public ItemInfo(String name, int life, int atk, int quick) {
this.name = name;
this.life = life;
this.atk = atk;
this.quick = quick;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public int getLife() {
return life;
}

public void setLife(int life) {
this.life = life;
}

public int getAtk() {
return atk;
}

public void setAtk(int atk) {
this.atk = atk;
}

public int getQuick() {
return quick;
}

public void setQuick(int quick) {
this.quick = quick;
}
}

4.创建ShopActivity

ShopActivity是用来展示装备信息的，当单击ShopActivity的装备时，回调会MainActivity并将装备信息回传给MainActivity。代码：

public class Shopping extends AppCompatActivity implements View.OnClickListener{
private ItemInfo itemInfo;

protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_shopping);
itemInfo = new ItemInfo("金剑", 100, 20, 20);
findViewById(R.id.rl).setOnClickListener(this);
TextView mLifeTV = (TextView) findViewById(R.id.tv_1);
TextView mNameTV = (TextView) findViewById(R.id.tv_name);
TextView mSpeedTV = (TextView) findViewById(R.id.tv_3);
TextView mAttackTV = (TextView) findViewById(R.id.tv_2);

mLifeTV.setText("生命值+" + itemInfo.getLife());
mNameTV.setText(itemInfo.getName() + "");
mSpeedTV.setText("敏捷度+" + itemInfo.getQuick());
mAttackTV.setText("攻击力+" + itemInfo.getAtk());
}

@Override
public void onClick(View v) {

switch (v.getId()) {
case R.id.rl:
Intent intent = new Intent();
intent.putExtra("equipment", itemInfo);
setResult(1, intent);
finish();
break;
}
}
}

5.编写界面交互代码（MainActivity）

主要用于响应按钮的点击事件，并将返回装备信息显示到指定的ListView控件中，代码：

public class MainActivity extends AppCompatActivity {

private ProgressBar mProgressBar1;
private ProgressBar mProgressBar2;
private ProgressBar mProgressBar3;
private TextView mLifeTV;
private TextView mAttackTV;
private TextView mSpeedTV;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mLifeTV = (TextView) findViewById(R.id.tv_life);
mAttackTV = (TextView) findViewById(R.id.tv_atk);
mSpeedTV = (TextView) findViewById(R.id.tv_quick);
initProgress();
}

private void initProgress() {
mProgressBar1 = (ProgressBar) findViewById(R.id.pro1);
mProgressBar2 = (ProgressBar) findViewById(R.id.pro2);
mProgressBar3 = (ProgressBar) findViewById(R.id.pro3);
mProgressBar1.setMax(1000);
mProgressBar2.setMax(1000);
mProgressBar3.setMax(1000);
}

public void click_1(View view) {
Intent intent = new Intent(this, Shopping.class);
startActivityForResult(intent, 1);
}

public void click_2(View view) {
Intent intent = new Intent(this, Shopping.class);
startActivityForResult(intent, 1);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (data != null) {

if (resultCode == 1) {
if (requestCode == 1) {
ItemInfo info= (ItemInfo) data.getSerializableExtra("equipment");

updateProgress(info);
}
}
}
}

private void updateProgress(ItemInfo info) {
int progress1 = mProgressBar1.getProgress();
int progress2 = mProgressBar2.getProgress();
int progress3 = mProgressBar3.getProgress();
mProgressBar1.setProgress(progress1+info.getLife());
mProgressBar2.setProgress(progress2+info.getAtk());
mProgressBar3.setProgress(progress3+info.getQuick());
mLifeTV.setText(mProgressBar1.getProgress()+"");
mAttackTV.setText(mProgressBar2.getProgress() + "");
mSpeedTV.setText(mProgressBar3.getProgress() + "");
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {

return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

int id = item.getItemId();

return super.onOptionsItemSelected(item);
}
}

6.配置清单文件

代码：

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

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