使用自定义对象时在活动 android 之间传递数据时出错

Question

当我有意传递这个对象时，它没有启动 activity。

Custom object code

public class UserVo implements Serializable {

String name,id;
String can_reply,can_view;

public String getName() {
    return name;
}

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

public String getId() {
    return id;
}

public String getCan_reply() {
    return can_reply;
}

public void setCan_reply(String can_reply) {
    this.can_reply = can_reply;
}

public String getCan_view() {
    return can_view;
}

public void setCan_view(String can_view) {
    this.can_view = can_view;
}

public void setId(String id) {
    this.id = id;
}

Sending data through the intent

   intent.putExtra("UserVo",vo);
   intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
     startActivity(intent);
        finish();

Receiving data

    intent=getIntent();
    UserVo vo= (UserVo) intent.getSerializableExtra("UserVo");

我也试过bundle，还是不行

Answer 1

如果由于某种原因，您不能使您的对象成为 Parcelable，请尝试添加一个 serialVersionUID。您可以通过 IDE 生成它或自己选择一个。

Answer 2

对于 UserVo，您将拥有

UserVo implements Parcelable {
...
...
public UserVo (){

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

  @Override public void writeToParcel(Parcel dest, int flags) {

    dest.writeString(name);
    + other data ...writInt etc 

}

public void readFromParcel(Parcel source){
    name = source.readString();
    + other data ..keep the same order
}
public static final Parcelable.Creator<DocumentFile> CREATOR = new Parcelable.Creator<UserVo>() {

    @Override
    public UserVo createFromParcel(Parcel source) {
        return new UserVo(source);
    }

    @Override
    public UserVo[] newArray(int size) {
        return new UserVo[size];
    }
};
public UserVo(Parcel source )
{
    readFromParcel(source);
}

也看看注释库，使用@Extra 注释发送数据会很容易。

Answer 3

看看这个linkSerializable:

Every serializable class is assigned a version identifier called a serialVersionUID. By default, this identifier is computed by hashing the class declaration and its members. This identifier is included in the serialized form so that version conflicts can be detected during deserialization. If the local serialVersionUID differs from the serialVersionUID in the serialized data, deserialization will fail with an InvalidClassException.

要避免它：

You can avoid this failure by declaring an explicit serialVersionUID. Declaring an explicit serialVersionUID tells the serialization mechanism that the class is forward and backward compatible with all versions that share that serialVersionUID. Declaring a serialVersionUID looks like this: private static final long serialVersionUID = 0L;

记住：

If you declare a serialVersionUID, you should increment it each time your class changes incompatibly with the previous version. Typically this is when you add, change or remove a non-transient field.

为了获得最佳实践，我建议您使用 Parcelable。编码更难，但性能更好。

Answer 4

为了将自定义对象从一个 Activity 发送到其他，您必须使用 serialVersionID 序列化对象。根据您的要求尝试以下修改后的代码。

UserVo.java

public class UserVo implements Serializable {

private static final long serialVersionUID = 1L;

String name,id;
String can_reply,can_view;

public String getName() {
    return name;
} 

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

public String getId() {
    return id;
} 

public String getCan_reply() {
    return can_reply;
} 

public void setCan_reply(String can_reply) {
    this.can_reply = can_reply;
} 

public String getCan_view() {
    return can_view;
} 

public void setCan_view(String can_view) {
    this.can_view = can_view;
} 

public void setId(String id) {
    this.id = id;
}

ActivityA.java - 通过Intent发送对象

Intent objectIntent = new Intent(ActivityA.this, ActivityB.class);
i.putExtra("sendObjects", UserVo ); //Your object here
startActivity(objectIntent);

ActivityB.java - 接收 Intent

UserVo mReceiveObjects = (UserVo)getIntent().getExtras().get("sendObjects");

使用自定义对象时在活动 android 之间传递数据时出错

Error in passing data between activites android while using a custom object

android

object

serializable

android-activity