Android笔记——Activity中的回传数据案例（装备选择）

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="@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通常用于访问网络展示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 + "]";    }}

需要注意的是，Intent除了传递基本类型之外，只能传递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,运行会出错        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，从这段代码中可以看出，使用setResult（）方法跳转Activity不需要指定要跳转的Activity。setReult（）方法的作用是让当前Activity返回到它的调用者，在这里可以理解为让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并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) {            // 判断结果码是否等于1,等于1为主人添加装备,等于2为宝宝添加装备            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>