方法一、java的序列化接口:java.io.Serializable,操作簡單,序列化的操作由系統完成,所以速度慢:
1、新建User.java類,寫上get和set方法、構造方法,並實現Serializable:
package top.javaer.app.sound;
import java.io.Serializable;
/**
* Created by Administrator on 2018/1/16.
*/
public class User implements Serializable {
public String name;
public int age;
public String getName() {
return name;
}
public int getAge() {
return age;
}
public void setName(String name) {
this.name = name;
}
public void setAge(int age) {
this.age = age;
}
public User(String name, int age) {
this.name = name;
this.age = age;
}
}
2、在第一個MainActivity中,通過Intent的putExtra(String name, Serializable value)方法,傳遞值對象:
package top.javaer.app.sound;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import java.io.Serializable;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.startAnotherActivity).setOnClickListener(new View.OnClickListener() {
/**
* Activity之間通過Intent傳遞自定義的值對象
* @param view
*/
@Override
public void onClick(View view) {
Intent i = new Intent(MainActivity.this, SecondActivity.class);
i.putExtra("user", new User("Jamie", 20));
startActivity(i);
}
});
}
}
3、在第二個SecondActivity中,通過getIntent().getSerializable(String name)方法,接收傳遞過來的值對象:package top.javaer.app.sound;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;
public class SecondActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
// Activity獲取Intent傳遞過來的值對象
TextView textView = findViewById(R.id.secondText);
User user = (User) getIntent().getSerializableExtra("user");
textView.setText(String.format("user info(name=%s, age=%d)", user.getName(), user.getAge()));
}
}
結果顯示:user info(name=Jamie, age=20)方法二、Android的Parcelable接口,Android系統中,專門針對於移動設備的序列化接口,效率更高,但操作稍複雜一些, 序列化沒有使用系統的序列化機制,需要自己手動完成,速度快:
1、將User.java類實現android.os的Parcelable接口,並實現describleContents()方法、writeToParcel(Parcel parcel, int i)方法。
(1)在writeToParcel方法中,將User的兩個屬性數據保存進去,方便傳遞給其它的程序或其他的組件;
(2)此時User類還是有錯,光標放到User上會提示Add Parcel implementation,點擊後自動創建Creator,泛型爲User,裏面有2個方法:
①、createFromParcel(Parcel in):通過Parcel創建對象,方法返回一個new User(in.readString(), in.readInt()),把User的兩個屬性數據讀取出來;
②、newArray(int size):創建一個數組,大小爲size;
package top.javaer.app.sound;
import android.os.Parcel;
import android.os.Parcelable;
/**
* Created by Administrator on 2018/1/16.
*/
public class User implements Parcelable {
public String name;
public int age;
protected User(Parcel in) {
name = in.readString();
age = in.readInt();
}
public String getName() {
return name;
}
public int getAge() {
return age;
}
public void setName(String name) {
this.name = name;
}
public void setAge(int age) {
this.age = age;
}
public User(String name, int age) {
this.name = name;
this.age = age;
}
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel parcel, int i) {
parcel.writeString(getName());
parcel.writeInt(getAge());
}
public static final Creator<User> CREATOR = new Creator<User>() {
@Override
public User createFromParcel(Parcel in) {
return new User(in.readString(), in.readInt());
}
@Override
public User[] newArray(int size) {
return new User[size];
}
};
}
2、MainActivity,通過Intent的putExtra(String name, Parcelable value)方法,傳遞值對象::
package top.javaer.app.sound;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.startAnotherActivity).setOnClickListener(new View.OnClickListener() {
/**
* Activity之間通過Intent傳遞自定義的值對象
* @param view
*/
@Override
public void onClick(View view) {
Intent i = new Intent(MainActivity.this, SecondActivity.class);
i.putExtra("user", new User("Jamie", 20));
startActivity(i);
}
});
}
}
3、SecondActivity,通過getIntent().getParcelableExtra(String name)方法,接收傳遞過來的值對象::
package top.javaer.app.sound;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;
public class SecondActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
// Activity獲取Intent傳遞過來的值對象
TextView textView = findViewById(R.id.secondText);
// User user = (User) getIntent().getSerializableExtra("user");
User user = (User) getIntent().getParcelableExtra("user");
textView.setText(String.format("user info(name=%s, age=%d)", user.getName(), user.getAge()));
}
}
結果顯示:user info(name=Jamie, age=20)總結:對比以上2種方法,結果是一樣的,區別如下:
(1)Serializable操作簡單:
調用的是java的序列化接口:java.io.Serializable,序列化的操作由系統完成,所以速度慢:
(2)Parcelable操作複雜:
調用的是Android系統的Parcelable接口,是Android系統中,專門針對於移動設備的序列化接口,效率更高,但操作稍複雜一些, 序列化沒有使用系統的序列化機制,需要自己手動完成,速度快:
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