Android在多个Activity间传递对象及对象数组
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- UID
- 1029342
- 性别
- 男
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Android在多个Activity间传递对象及对象数组
假设对象为People类，包含信息姓名和年龄：
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| public class People{
public String strName;
public int iAge;
public People(String strName,int iAge){
this.strName = strName;
this.iAge = iAge;
}
public String getName(){
return strName;
}
public int getAge(){
return iAge;
}
}
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方法一：Serializable
必须条件：类实现了Serializable接口
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| public class People implements Serializable{
private static final long serialVersionUID = 1L;
public String strName;
public int iAge;
public People(String strName,int iAge){
this.strName = strName;
this.iAge = iAge;
}
public String getName(){
return strName;
}
public int getAge(){
return iAge;
}
}
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传递对象：
传递端：
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| People people = new People("John", 21);
Intent intent = new Intent(SendActivity.this,RcvActivity.class);
Bundle bundle = new Bundle();
bundle.putSerializable("people", people);
intent.putExtras(bundle);
startActivity(intent);
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接收端：
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| People people = (People) this.getIntent().getSerializableExtra("people");
String strData = people.getName() + " " + people.getAge();
Toast.makeText(getApplication(),strData, Toast.LENGTH_SHORT).show();
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传递对象数组：
传递端：
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| List<people> people = new ArrayList<people>();
people.add(new People("John", 21));
people.add(new People("Amy", 20));
Bundle bundle = new Bundle();
bundle.putSerializable("people", (Serializable) people);
Intent intent = new Intent(SendActivity.this, RcvActivity.class);
intent.putExtras(bundle);
startActivity(intent);
</people></people>
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接收端：
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| List<people> resultList = (List<people>) this.getIntent().getSerializableExtra("people");
String strData = "";
for (People p : resultList) {
strData = strData + p.strName + " " + p.iAge + "\n";
}
Toast.makeText(getApplication(), strData, Toast.LENGTH_SHORT).show();
</people></people>
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方法二：Parcelable
必须条件：类实现了Parcelable接口
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| public class People implements Parcelable {
public String strName;
public int iAge;
public People(String strName,int iAge){
this.strName = strName;
this.iAge = iAge;
}
public String getName(){
return strName;
}
public int getAge(){
return iAge;
}
@Override
public int describeContents() {
// TODO Auto-generated method stub
return 0;
}
@Override
public void writeToParcel(Parcel parcel, int arg1) {
// TODO Auto-generated method stub
parcel.writeString(strName);
parcel.writeInt(iAge);
}
public static final Parcelable.Creator<people> CREATOR = new Creator<people>() {
public People createFromParcel(Parcel source) {
People pTemp = new People("",0);
pTemp.strName = source.readString();
pTemp.iAge = source.readInt();
return pTemp;
}
public People[] newArray(int size) {
return new People[size];
}
};
}
</people></people>
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传递对象： 传递端：
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| People people = new People("John", 21);
Intent intent = new Intent(SendActivity.this,RcvActivity.class);
Bundle bundle = new Bundle();
bundle.putParcelable("people", people);
intent.putExtras(bundle);
startActivity(intent);
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接收端：
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| People people = (People) this.getIntent().getParcelableExtra("people");
String strData = people.getName() + " " + people.getAge();
Toast.makeText(getApplication(),strData, Toast.LENGTH_SHORT).show();
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传递对象数组： 传递端：
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| List<people> People = new ArrayList<people>();
People.add(new People("John", 21));
People.add(new People("Amy", 20));
Intent intent = new Intent(SendActivity.this,RcvActivity.class);
Bundle bundle = new Bundle();
bundle.putParcelableArrayList("People", (ArrayList<!--? extends Parcelable-->) People);
intent.putExtras(bundle);
startActivity(intent);
</people></people>
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接收端：
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| List<people> resultList = this.getIntent().getExtras()
.getParcelableArrayList("People");
String strData = "";
for (People p : resultList) {
strData = strData + p.strName + " " + p.iAge + "\n";
}
Toast.makeText(getApplication(), strData, Toast.LENGTH_SHORT).show();
</people>
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可以发现在Parcelable中需实现public int describeContents()、 publicvoid writeToParcel(Parcel parcel, int arg1)，还需要在添加一个静态成员变量CREATOR：public static final Parcelable.Creator CREATOR。区别(by: http://www.cnblogs.com/renqingpi ... /25/Parcelable.html)
1.Serializable的实现，只需要implements Serializable即可。这只是给对象打了一个标记，系统会自动将其序列化。
2.Parcelabel的实现，不仅需要implements Parcelabel，还需要在类中添加一个静态成员变量CREATOR，这个变量需要实现 Parcelable.Creator 接口。
3.在使用内存的时候，Parcelable 类比Serializable性能高，所以推荐使用Parcelable类。4.Serializable在序列化的时候会产生大量的临时变量，从而引起频繁的GC。
5.Parcelable不能使用在要将数据存储在磁盘上的情况，因为在外界有变化的情况下Parcelable不能很好的保证数据的持续性。 |
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