java - 使用 gson 将自定义数组列表保存到共享首选项
问题描述
我正在尝试将我的应用程序状态保存到共享首选项。我要保存的信息是自定义对象的数组列表,其中每个对象(PatientInfo)包含一些字符串和另外 2 个自定义数组列表(SkinPhotoInfo、TreatmentsInfo)。我能够保存和加载自定义对象的数组列表,但我无法保存其中包含数组列表的数组列表。
任何人都知道最简单的方法是什么?如果它以任何方式提供帮助,对象本身就已经可以分析了。
PS 何时是保存到共享首选项的最佳时间 - onPause 或 onDelete?
感谢您的帮助!!
患者信息:
public class PatientInfo implements Parcelable {
String name;
String skinType;
String notes;
String image;
ArrayList<SkinPhotoInfo> skinPhotos;
ArrayList<TreatmentsInfo> treatments;
Boolean showDeleteButton;
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(name);
dest.writeString(skinType);
dest.writeString(notes);
dest.writeValue(image);
dest.writeValue(skinPhotos);
dest.writeValue(treatments);
}
public static final Creator<PatientInfo> CREATOR = new Creator<PatientInfo>()
{
@Override
public PatientInfo createFromParcel(Parcel source) {
PatientInfo ret = new PatientInfo();
ret.name = source.readString();
ret.skinType = source.readString();
ret.notes = source.readString();
ret.image = (String)source.readString();
ret.skinPhotos = source.readArrayList(null);
ret.treatments = source.readArrayList(null);
return ret;
}
@Override
public PatientInfo[] newArray(int size) {
return new PatientInfo[size];
}
};
public PatientInfo() {
this.name = "";
this.skinType = "";
this.image = "";
this.skinPhotos = new ArrayList<SkinPhotoInfo>();
this.showDeleteButton = false;
this.treatments = new ArrayList<TreatmentsInfo>();
}}
皮肤照片信息:
public class SkinPhotoInfo implements Parcelable {
String photoDate;
Boolean showDeleteButton;
Uri imageUri;
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(photoDate);
dest.writeByte((byte)(showDeleteButton ? 1 : 0)); // If showDeleteButton == true, byte == 1
dest.writeValue(imageUri);
}
public static final Creator<SkinPhotoInfo> CREATOR = new Creator<SkinPhotoInfo>()
{
@Override
public SkinPhotoInfo createFromParcel(Parcel source) {
SkinPhotoInfo ret = new SkinPhotoInfo();
ret.skinImageThumnail = (Bitmap)source.readValue(Bitmap.class.getClassLoader());
ret.photoDate = source.readString();
ret.showDeleteButton = source.readByte() != 1;
ret.imageUri = (Uri) source.readValue(Uri.class.getClassLoader());
return ret;
}
@Override
public SkinPhotoInfo[] newArray(int size) {
return new SkinPhotoInfo[size];
}
};
public SkinPhotoInfo(Uri imageUri, String photoDate) {
this.imageUri = imageUri;
this.photoDate = photoDate;
showDeleteButton = false;
}}
治疗信息:
public class TreatmentsInfo implements Parcelable {
String treatmentDate;
String treatmentName;
String pattern = "MM-dd-yy";
Boolean showDeleteButton;
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(treatmentDate);
dest.writeString(treatmentName);
dest.writeString(pattern);
dest.writeByte((byte)(showDeleteButton ? 1 : 0)); // If showDeleteButton == true, byte == 1
}
public static final Creator<TreatmentsInfo> CREATOR = new Creator<TreatmentsInfo>()
{
@Override
public TreatmentsInfo createFromParcel(Parcel source) {
TreatmentsInfo ret = new TreatmentsInfo();
ret.treatmentDate = source.readString();
ret.treatmentName = source.readString();
ret.pattern = source.readString();
ret.showDeleteButton = source.readByte() != 1;
return ret;
}
@Override
public TreatmentsInfo[] newArray(int size) {
return new TreatmentsInfo[size];
}
};
public TreatmentsInfo(){
this.treatmentDate = "";
this.treatmentName = "";
this.showDeleteButton = false;
this.pattern = "";
}
public TreatmentsInfo(String treatmentDate, String treatmentName) {
this.treatmentDate = treatmentDate;
this.treatmentName = treatmentName;
this.showDeleteButton = false;
}}
解决方案
您可以执行以下操作:
String json = new Gson().toJson(YourObject);
保存在共享首选项中。要检索 json 并将其转换为 YourObejct,只需执行以下操作:
String json = myPrefsObject.getString(TAG, "");
return new Gson().fromJson(json, YourObject.class);
至于PS问题,答案是onPause。让我知道您是否需要其他东西
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