Parcelable 替换字段对象的值？答案

【问题标题】：Parcelable replacing field object's values?Parcelable 替换字段对象的值？
【发布时间】：2020-08-18 02:04:43
【问题描述】：

我正在将ArrayList<Contact> 中的Parcelable 对象从Activity1 发送到Activity2。

在我真正将对象发送到 Activity2 之前，我做了简单的Log.i() 函数。它打印出来：

I/String representation from Activity1: Contact{id=1, firstName='John', lastName='Doe', email='john@gmail.com', photoPath='/storage/emulated/0/Pictures/Screenshots/Screenshot_20200502-094346__02.jpg', note='some notes'}

在 Activity2 中，它打印出以下内容：

I/String representation from Activity2: Contact{id=6, firstName='1', lastName='John', email='Doe', photoPath='john@gmail.com', note='/storage/emulated/0/Pictures/Screenshots/Screenshot_20200502-094346__02.jpg'}

对象完全搞砸了。 id 不可能为 6，因为我在 db 中只有一个对象。其他字段可以自己查看。

最后，这里是完整的Contact类：

public class Contact implements Parcelable{

    @SerializedName("id")
    @Expose
    private Integer id;

    @SerializedName("firstName")
    @Expose
    private String firstName;

    @SerializedName("lastName")
    @Expose
    private String lastName;

    @SerializedName("email")
    @Expose
    private String email;

    @SerializedName("photoPath")
    @Expose
    private String photoPath;

    @SerializedName("note")
    @Expose
    private String note;


    public Contact(){
        //photoPath = "";
    }

    public Contact(Integer id, String firstName, String lastName, String email, String photoPath, String note) {
        this.id = id;
        this.firstName = firstName;
        this.lastName = lastName;
        this.email = email;
        this.photoPath = photoPath;
        this.note = note;
    }

    protected Contact(Parcel in) {
        id = in.readInt();
        firstName = in.readString();
        lastName = in.readString();
        email = in.readString();
        photoPath = in.readString();
        note = in.readString();

    }

    public Integer getId() {
        return id;
    }

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

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPhotoPath() {
        return photoPath;
    }

    public void setPhotoPath(String photoPath) {
        this.photoPath = photoPath;
    }

    public String getNote() {
        return note;
    }

    public void setNote(String note) {
        this.note = note;
    }

    public String getPhotoFilename() {
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        // Log.i("timestampe", timeStamp);
        return "IMG_" + getId() + "_" + timeStamp + ".jpg";
    }

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

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

        dest.writeStringArray(new String[]{this.id.toString(), this.firstName, this.lastName, this.email, this.photoPath, this.note});

        /*dest.writeString(this.id.toString());
        dest.writeString(this.firstName);
        dest.writeString(this.lastName);
        dest.writeString(this.email);
        dest.writeString(this.photoPath);
        dest.writeString(this.note);*/
    }

    public static final Parcelable.Creator<Contact> CREATOR= new Parcelable.Creator<Contact>() {
        @Override
        public Contact createFromParcel(Parcel source) {
             // TODO Auto-generated method stub
            return new Contact(source);  //using parcelable constructor
        }

        @Override
        public Contact[] newArray(int size) {
            // TODO Auto-generated method stub
            return new Contact[size];
        }

    };

    @Override
    public String toString() {
        return "Contact{" +
                "id=" + id +
                ", firstName='" + firstName + '\'' +
                ", lastName='" + lastName + '\'' +
                ", email='" + email + '\'' +
                ", photoPath='" + photoPath + '\'' +
                ", note='" + note + '\'' +
                '}';
    }
}

from writeToParcel() 这两个选项我都试过了，都没用。

【问题讨论】：

您的writeToParcel 都不匹配您的Contact(Parcel in) 构造函数。你在哪里writeInt() 匹配你的readInt()？
啊，我想我明白了。在 protected Contact(Parcel in) 中应该有 id = in.readInt() 并且在 writeToParcel(Parcel dest, int flags) 中应该有 dest.writeInt(this.id)。

标签： android android-intent android-activity parcelable

【解决方案1】：

您的writeToParcel() 需要与您的Contact(Parcel in) 完全匹配：如果您使用readInt()，则需要以完全相同的顺序使用writeInt()。

【讨论】：

【解决方案2】：

是的，伊恩，我确实喜欢你在评论中提出的建议。现在可以了。谢谢你:)

protected Contact(Parcel in) {
    id = in.readInt();
    firstName = in.readString();
    lastName = in.readString();
    email = in.readString();
    photoPath = in.readString();
    note = in.readString();
}


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

    dest.writeInt(this.id);
    dest.writeString(this.firstName);
    dest.writeString(this.lastName);
    dest.writeString(this.email);
    dest.writeString(this.photoPath);
    dest.writeString(this.note);
}

【讨论】：