android 对象传输及parcel机制

在开发中不少要用到Activity直接传输对象，下面我们来看看，其实跟java里面差不多
   自定义对象的传递：通过intent传递自定义对象的方法有两个
  第一是实现Serialization接口；
  第二是实现Parcelable接口；

下面来看个例子：

package com.example.bean;

 import java.io.Serializable;

 public class Bed implements Serializable {

  private String name;
  private int number;

  public String getName() {
   return name;
  }

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

  public int getNumber() {
   return number;
  }

  public void setNumber(int number) {
   this.number = number;
  }

  @Override
  public String toString() {
   return "Name：" + getName() + "，Number：" + getNumber();
  }

 }

package com.example.bean;

 import android.os.Parcel;
 import android.os.Parcelable;

 public class Patient implements Parcelable {

 private String name;
 private int number;

 public String getName() {
  return name;
 }

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

 public int getNumber() {
  return number;
 }

 public void setNumber(int number) {
  this.number = number;
 }

 public static final Parcelable.Creator<Patient> CREATOR = new Parcelable.Creator<Patient>() {
  public Patient createFromParcel(Parcel p) {
   Patient patient = new Patient();
   patient.name = p.readString();
   patient.number = p.readInt();
   return patient;
  }

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

 @Override
 public int describeContents() {
  return 0;
 }

 /**
 *
 *@desc  注：这里的write方法和createFromParcel里的一一对应，不然createFromParcel都是p.readString()，你怎么知道是哪一个
 *
 */
 @Override
 public void writeToParcel(Parcel p, int flags) {
  p.writeString(name);
  p.writeInt(number);
 }

 @Override
 public String toString() {
  return "Name：" + getName() + "，Number：" + getNumber();
 }

}

TestActivity.java：

  StringBuilder sb = new StringBuilder();

  sb.append("Serializable Bed对象\n");

  Bed bed = (Bed) getIntent().getExtras().get("bed");
  sb.append(bed.toString());

  sb.append("\n\nList<Serializable Bed>集合\n");

  List<Bed> listBed = (List<Bed>) getIntent()
    .getSerializableExtra("beds");
  for (int i = 0; i < listBed.size(); i++) {
   sb.append(listBed.get(i).toString() + "；");
  }

  sb.append("\n\nParcelable Patient对象\n");

  Patient patient = getIntent().getParcelableExtra("patient1");
  sb.append(patient.toString());

  sb.append("\n\nParcelable Patient byte[]\n");

  byte[] data = getIntent().getByteArrayExtra("patient2");
  if (data != null) {
   Parcel in = Parcel.obtain();
   in.unmarshall(data, 0, data.length);
   in.setDataPosition(0);
   patient = Patient.CREATOR.createFromParcel(in);
  }
  sb.append(patient.toString());

  sb.append("\n\nString数组\n");

  String[] str = getIntent().getStringArrayExtra("patients");
  for (int i = 0; i < str.length; i++) {
   sb.append(str[i]);
  }

  TextView tv = (TextView) findViewById(R.id.tv);
  tv.setText(sb);