案例——装备选择

通过案例装备选择来演示Activity回传数据。实现案例的具体步骤如下：

1.创建程序

创建一个工程，包名为cn.edu.bzu.com，设计用户交互界面，如图：



装备选择程序对应的布局文件（activity_main.xml）如下：

<?xml version="1.0" encoding="utf-8"?>
<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"
android:weightSum="1"
tools:context="com.edu.bzu.cn.activitydemo.MainActivity">

<ImageView
android:layout_width="86dp"
android:layout_height="109dp"
android:layout_gravity="center_horizontal"
android:layout_marginTop="80dp"
android:src="@drawable/image" />

<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
android:text="主人，快给小宝宝购买装备吧"
android:textSize="18sp" />

<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_height="wrap_content"
android:layout_weight="1"
android:text="生命值："
android:textColor="@android:color/black"
android:textSize="14sp" />

<ProgressBar
android:id="@+id/progressBar1"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_weight="3" />

<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_weight="1"
android:text="0"
android:textColor="#000000" />
</TableRow>

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

<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="攻击力："
android:textColor="@android:color/black"
android:textSize="14sp" />

<ProgressBar
android:id="@+id/progressBar2"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_weight="3" />

<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_marginTop="5dp"
android:layout_weight="1"
a
4000
ndroid:text="0"
android:textColor="#000000" />
</TableRow>

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

<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="敏捷："
android:textColor="@android:color/black"
android:textSize="14sp" />

<ProgressBar
android:id="@+id/progressBar3"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_weight="3" />

<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_weight="1"
android:text="0"
android:textColor="#000000" />
</TableRow>
</TableLayout>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="25dp"
android:orientation="horizontal">

<Button
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:drawableRight="@android:drawable/ic_menu_add"
android:onClick="click1"
android:text="主人购买装备" />

<Button
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:drawableRight="@android:drawable/ic_menu_add"
android:onClick="click2"
android:text="小宝宝购买装备" />
</LinearLayout>

</LinearLayout>

2.创建装备界面

创建界面activity_shop.xml，用来展示装备，界面编写完成后，如图：



购买装备界面（activity_shop.xml）对应的布局文件如下：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/r1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">

<View
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_alignParentLeft="true"
android:layout_centerVertical="true"
android:background="@android:drawable/ic_menu_info_details" />

<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_life"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="生命值"
android:textSize="13sp" />

<TextView
android:id="@+id/tv_attack"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="攻击力"
android:textSize="13sp" />

<TextView
android:id="@+id/tv_speed"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="速度"
android:textSize="13sp" />

</LinearLayout>
</RelativeLayout>

3.创建ItemInfo类

在程序中创建一个cn.edu.bzu.domain包，在该包中创建一个ItemInfo类，用来封装装备信息。代码如下：

package cn.edu.bzu.domain;

import java.io.Serializable;

public class ItemInfo implements Serializable {
private String name;
private int acctack;
private int life;
private int speed;

public ItemInfo(String name, int acctack, int life, int speed) {
this.name = name;
this.acctack = acctack;
this.life = life;
this.speed = speed;
}

public String getName() {
return name;
}

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

public int getAcctack() {
return acctack;
}

public void setAcctack(int acctack) {
this.acctack = acctack;
}

public int getLife() {
return life;
}

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

public int getSpeed() {
return speed;
}

public void setSpeed(int speed) {
this.speed = speed;
}

public String toString() {
return "[name=" + name + ",acctack=" + acctack + ",life=" + life + ",speed=" + speed + "]";
}

}

4.创建ShopActivity

ShopActivity是用来展示装备信息的，当单击 ShopActivity的装备时，会调回MainActivity并将信息回传给MainActivity。代码如下：

package com.edu.bzu.cn.activitydemo;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

import cn.edu.bzu.domain.ItemInfo;

public class ShopActivity extends Activity implements View.OnClickListener {
private ItemInfo itemInfo;

protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_shop);
itemInfo = new ItemInfo("宝剑", 100, 20, 20);
findViewById(R.id.r1).setOnClickListener(this);
TextView mLifeTV = (TextView) findViewById(R.id.tv_life);
TextView mNameTV = (TextView) findViewById(R.id.tv_name);
TextView mSpeedTV = (TextView) findViewById(R.id.tv_speed);
TextView mAttackTV = (TextView) findViewById(R.id.tv_attack);
mLifeTV.setText("生命值+" + itemInfo.getLife());
mNameTV.setText(itemInfo
b930
.getName() + "");
mSpeedTV.setText("敏捷度+" + itemInfo.getSpeed());
mAttackTV.setText("攻击力+" + itemInfo.getAcctack());
}

@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.r1:
Intent intent = new Intent();
intent.putExtra("equipment", itemInfo);
setResult(1, intent);
finish();
break;
}
}
}

5.编写界面交互代码（MainActivity）

MainActivity主要用于影响按钮的点击事件，并将返回的装备信息显示到指定的ListView控件中。代码如下：

package com.edu.bzu.cn.activitydemo;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ProgressBar;
import android.widget.TextView;

import cn.edu.bzu.domain.ItemInfo;

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_attack);
mSpeedTV=(TextView)findViewById(R.id.tv_speed);
initProgress();//初始化进度条
}
private void initProgress(){
mProgressBar1=(ProgressBar)findViewById(R.id.progressBar1);
mProgressBar2=(ProgressBar)findViewById(R.id.progressBar2);
mProgressBar3=(ProgressBar)findViewById(R.id.progressBar3);
mProgressBar1.setMax(1000);
mProgressBar2.setMax(1000);
mProgressBar3.setMax(1000);

}
//开启新的activity并且想获取它的返回值
public void click(View view){
Intent intent=new Intent(this,ShopActivity.class);
startActivityForResult(intent,1);//返回请求结果，请求吗为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.getAcctack());
mProgressBar3.setProgress(progress3+info.getSpeed());
mLifeTV.setText(mProgressBar1.getProgress()+"");
mAttackTV.setText(mProgressBar2.getProgress()+"");
mSpeedTV.setText(mProgressBar3.getProgress()+"");
}
}

6.清单文件的配置

使用Activity时需要在清单文件中配置。代码如下：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.edu.bzu.cn.activitydemo">

<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=".ShopActivity"></activity>
</application>

</manifest>

7.运行程序选择装备

运行程序，在主界面分别单击“主人购买装备”“小宝宝 购买装备”按钮，会跳转至装备展示页面，装备购买成功后，会看到如图所示界面：