Android笔记——Activity中的回传数据案例（装备选择）

Posted 2020-09-14 lxjshuju

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>