【发布时间】:2017-11-22 13:15:17
【问题描述】:
我不断收到以下错误:
无法弄清楚如何将此字段保存到数据库中。你可以 考虑为它添加一个类型转换器。
我已将@TypeConverter 添加到我的数据库类上的一对转换器方法和@TypeConverters 注释中。
下载Item.java
@Entity(tableName = "downloads")
public class DownloadItem implements Serializable {
public enum DownloadStatus {
None(0),
Downloading(1),
Suspended(2),
Completed(3),
Deleted(4),
Expired(5);
private final int numeral;
@TypeConverter
public static DownloadStatus getDownloadStatus(int numeral){
for(DownloadStatus ds : values()){
if(ds.numeral == numeral){
return ds;
}
}
return null;
}
@TypeConverter
public static Integer getDownloadStatusInt(DownloadStatus status){
return status.numeral;
}
DownloadStatus(int num){
this.numeral = num;
}
}
@TypeConverters(DownloadStatus.class)
@ColumnInfo(name = "download_status")
public DownloadStatus downloadStatus;
@PrimaryKey
@NonNull
private int contentId;
@Ignore
public DownloadItem() {
}
public DownloadItem(DownloadStatus downloadStatus, int contentId) {
this.downloadStatus = downloadStatus;
this.contentId = contentId;
}
}
下载Database.java
@Database(entities = {DownloadItem.class}, version = 1)
@TypeConverters({DownloadItem.DownloadStatus.class, PlayerType.class})
public abstract class DownloadDatabase extends RoomDatabase {
public abstract DownloadItemStore downloadItemStore();
private static final String DB_NAME = "download.db";
.......
}
【问题讨论】:
-
当类名是DownloadItem时,LTDownloadItem是什么?
-
很好,我在发帖前更改了班级名称。已更正。 (我在代码中的实际类名都匹配)
-
我认为 getDownloadStatusInt @TypeConverter 应该是
int,而不是Integer。 -
@AlexCohn 你是对的!!!谢谢!!
标签: android enums orm android-room