Android中Activity在跳轉時傳遞實體類對象的實現（實體類含有布爾值）

原創

LayneYao

2020-02-20 21:52

實際開發中偶爾會有這樣的需求，在Activity跳轉的時候傳遞一個實體類對象。廢話少說，直接演示源碼。

其中實體類要實現Parcelable序列化接口，其實例可以從一個包中寫入和恢復。實現Parcelable接口的類還必須有一個名爲CREATOR的靜態字段，它是實現Parcelable的對象。

實體類的模板大概就是這樣：

 public class MyParcelable implements Parcelable {
     private int mData;

     public int describeContents() {
         return 0;
     }

     public void writeToParcel(Parcel out, int flags) {
         out.writeInt(mData);
     }

     public static final Parcelable.Creator<MyParcelable> CREATOR
             = new Parcelable.Creator<MyParcelable>() {
         public MyParcelable createFromParcel(Parcel in) {
             return new MyParcelable(in);
         }

         public MyParcelable[] newArray(int size) {
             return new MyParcelable[size];
         }
     };

     private MyParcelable(Parcel in) {
         mData = in.readInt();
     }
 }

好了直接演示我隨意寫的實體類：

/**
 * Created by Layne_Yao on 2018-2-26 下午4:27:00.
 * CSDN:http://blog.csdn.net/Jsagacity
 */
public class Person implements Parcelable {
    private String name;
    private int age;
    private String sex;
    private boolean isMarry;

    public Person(String name, int age, String sex, boolean isMarry) {
        super();
        this.name = name;
        this.age = age;
        this.sex = sex;
        this.isMarry = isMarry;
    }

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public boolean isMarry() {
        return isMarry;
    }

    public void setMarry(boolean isMarry) {
        this.isMarry = isMarry;
    }

    public Person(Parcel in) {
        name = in.readString();
        age = in.readInt();
        sex = in.readString();
        //將byte再轉化回布爾值
        isMarry = in.readByte() != 0;
    }

    public static final Creator<Person> CREATOR = new Creator<Person>() {
        @Override
        public Person createFromParcel(Parcel in) {
            return new Person(in);
        }

        @Override
        public Person[] newArray(int size) {
            return new Person[size];
        }
    };

    @Override
    public int describeContents() {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(name);
        dest.writeInt(age);
        dest.writeString(sex);
        //布爾值這裏是將之轉化成byte進行序列化
        dest.writeByte((byte) (isMarry ? 1 : 0));

    }

}

主佈局就一個跳轉按鈕：

<RelativeLayout 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="com.itman.skipdemo.MainActivity" >

   <Button
       android:id="@+id/btnSkip"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:layout_centerHorizontal="true"
       android:layout_centerVertical="true"
       android:text="跳轉" />

</RelativeLayout>

MainActivity中代碼：

public class MainActivity extends ActionBarActivity {
    private Button btnSkip;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btnSkip = (Button) findViewById(R.id.btnSkip);

        btnSkip.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Person person = new Person("Yorkie", 18, "female", false);
                Intent intent = new Intent(MainActivity.this,
                        FirstActivity.class);
                intent.putExtra("person", person);
                startActivity(intent);

            }
        });

    }

}

傳遞對象時，我發現網上一些做法是將對象通過Bundle的putParcelable(key, value)方法存進Bundle對象裏面，而後再將Bundle對象存進Intent裏面進行傳遞。但是我發現Intent也有存儲通過Parcelable序列化對象的方法：

沒有深究有何不同，演示了一下可以就行，如有不妥的可以指正出來。

接下來繼續，跳轉後頁面就一個顯示文本：

<RelativeLayout 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="com.itman.skipdemo.FirstActivity" >

    <TextView
        android:id="@+id/tvContent"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:text="@string/hello_world"
        android:textSize="25sp" />

</RelativeLayout>

FirstActivity的代碼：

public class FirstActivity extends ActionBarActivity {
    private TextView tvContent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_first);
        tvContent = (TextView) findViewById(R.id.tvContent);

        Person person = (Person) getIntent().getExtras().get("person");
        String info = "姓名:"+person.getName()+"\n年齡："+person.getAge()+"\n性別："+person.getSex()+"\n婚姻狀況："+person.isMarry();
        tvContent.setText(info);
    }

}