Android笔记——Activity中的回传数据案例（装备选择）

古之立大事者，不惟有超世之才，亦必有坚忍不拔之志。这篇文章主要讲述Android笔记——Activity中的回传数据案例（装备选择）相关的知识，希望能为你提供帮助。
1.创建程序：

< 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" tools:context=".Main" android:orientation="vertical" android:gravity="center"> < ImageView android:id="@+id/pet_imgv" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_horizontal" android:layout_marginBottom="5dp" android:layout_marginTop="30dp" android:src="https://www.songbingjia.com/android/@drawable/baby"/> < TextView android:id="@+id/pet_dialog_tv" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_horizontal" android:layout_marginBottom="25dp" android:gravity="center" android:text="主人，快给小宝宝购买装备吧" /> < TableLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_gravity="center" android:layout_marginBottom="20dp"> < TableRow android:layout_width="fill_parent" android:layout_height="wrap_content"> < TextView android:layout_width="0dip" 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="0dip" android:layout_height="wrap_content" android:layout_gravity="center" android:layout_weight="2"/> < TextView android:id="@+id/tv_life_progress" android:layout_width="0dip" android:layout_height="wrap_content" android:layout_weight="1" android:text="0" android:gravity="center" android:textColor="#000000"/> < /TableRow> < TableRow android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_marginTop="5dp"> < TextView android:layout_width="0dip" 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="0dip" android:layout_height="wrap_content" android:layout_weight="2" /> < TextView android:id="@+id/tv_attack_progress" android:layout_width="0dip" android:layout_height="wrap_content" android:layout_weight="1" android:text="0" android:gravity="center" android:textColor="#000000" /> < /TableRow> < TableRow android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_marginTop="5dp"> < TextView android:layout_width="0dip" 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="0dip" android:layout_height="wrap_content" android:layout_weight="2" /> < TextView android:id="@+id/tv_speed_progress" android:layout_width="0dip" android:layout_height="wrap_content" android:layout_weight="1" android:text="0" android:gravity="center" android:textColor="#000000" /> < /TableRow> < /TableLayout> < RelativeLayout android:layout_width="match_parent" android:layout_height="wrap_content" > < Button android:id="@+id/btn_master" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_alignParentTop="true" android:drawableRight="@android:drawable/ic_menu_add" android:onClick="click" android:drawablePadding="3dp" android:text="主人购买装备" android:textSize="14sp" /> < Button android:id="@+id/btn_baby" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentRight="true" android:layout_alignParentTop="true" android:drawablePadding="3dp" android:drawableRight="@android:drawable/ic_menu_add" android:onClick="click2" android:text="小宝宝购买装备" android:textSize="14sp" /> < /RelativeLayout> < /LinearLayout>

上述布局代码使用到了控件ProgressBar（进度条），它是用来显示小宝宝的生命值、攻击值和敏捷度的。
ProgressBar通经常使用于訪问网络展示Loading对话框以及下载文件时显示的进度。

2.创建装备界面：

< ?
xml version="1.0" encoding="utf-8"?> < 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_life" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="13sp" android:text="生命值" /> < TextView android:id="@+id/tv_attack" 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_speed" 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：

package select.itcast.cn.huichuan; /** * Created by wanglaoda on 15-8-2. */ import java.io.Serializable; //实现序列化方便传递数据 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 + "]"; } }

须要注意的是，Intent除了传递基本类型之外。仅仅能传递Serializable或Parcelable类型的数据，为了方便数据传递，在这里让ItemInfo类实现Serializable接口。
4.创建ShopActivity：

package select.itcast.cn.huichuan; /** * Created by wanglaoda on 15-8-2. */ import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.TextView; public class ShopActivity extends Activity implements OnClickListener {private ItemInfo itemInfo; protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_shop); itemInfo = new ItemInfo("金剑", 100, 20, 20); findViewById(R.id.rl).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); // TextView显示字符串,这里传入int值编译不会报错,执行会出错 mLifeTV.setText("生命值+" + itemInfo.getLife()); mNameTV.setText(itemInfo.getName() + ""); mSpeedTV.setText("敏捷度+" + itemInfo.getSpeed()); mAttackTV.setText("攻击力+" + itemInfo.getAcctack()); }@Override public void onClick(View v) { // TODO Auto-generated method stub switch (v.getId()) { case R.id.rl: Intent intent = new Intent(); intent.putExtra("equipment", itemInfo); setResult(1, intent); finish(); break; } } }

上述代码中的重点代码是后几行，从这段代码中能够看出。使用setResult（）方法跳转Activity不须要指定要跳转的Activity。setReult（）方法的作用是让当前Activity返回到它的调用者，在这里能够理解为让ShopActivity返回到MainActivity。

5.编写界面交互代码：

package select.itcast.cn.huichuan; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.ProgressBar; import android.widget.TextView; public class Main extends Activity {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_progress); mAttackTV = (TextView) findViewById(R.id.tv_attack_progress); mSpeedTV = (TextView) findViewById(R.id.tv_speed_progress); 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); //设置最大值1000 mProgressBar2.setMax(1000); mProgressBar3.setMax(1000); }// 开启新的activity而且想获取他的返回值 public void click(View view) { Intent intent = new Intent(this, ShopActivity.class); startActivityForResult(intent, 1); // 返回请求结果,请求码为1 }public void click2(View view) { Intent intent = new Intent(this, ShopActivity.class); startActivityForResult(intent, 1); }@Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); if (data != null) { // 推断结果码是否等于1,等于1为主人加入装备,等于2为宝宝加入装备 if (resultCode == 1) { if (requestCode == 1) { ItemInfo info= (ItemInfo) data.getSerializableExtra("equipment"); //更新ProgressBar的值 updateProgress(info); } } } } //更新ProgressBar的值 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() + ""); }@Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.menu_main, menu); return true; }@Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); //noinspection SimplifiableIfStatement if (id == R.id.action_settings) { return true; }return super.onOptionsItemSelected(item); } }

6.清单文件的配置：

< ?xml version="1.0" encoding="utf-8"?> < manifest xmlns:android="http://schemas.android.com/apk/res/android" package="select.itcast.cn.huichuan" > < application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > < activity android:name=".Main" android:label="@string/app_name" > < intent-filter> < action android:name="android.intent.action.MAIN" /> < category android:name="android.intent.category.LAUNCHER" /> < /intent-filter> < /activity> < activity android:name=".ShopActivity"/> < /application> < /manifest>