我正在尝试将Room Persistence库包含到我的android项目中。我正在使用gradle依赖项android.arch.persistence.room:runtime:1.1.1
库,而不是androidx
我尝试将版本更改为1.1.0
和1.1.0-beta2
,但遇到相同的错误。
Room的等级依赖性:
// Room components
implementation "android.arch.persistence.room:runtime:$rootProject.roomVersion"
annotationProcessor "android.arch.persistence.room:compiler:$rootProject.roomVersion"
androidTestImplementation "android.arch.persistence.room:testing:$rootProject.roomVersion"
此处$rootProject.roomVersion
的值为1.1.1
支持库版本:
`implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.android.support:support-v4:28.0.0'`
AppDatabase类:
import android.arch.persistence.room.Database;
import android.arch.persistence.room.Room;
import android.arch.persistence.room.RoomDatabase;
import android.content.Context;
import com.samcaraschools.userlistapp.module.User;
@Database(entities = {User.class},version = 1, exportSchema = false)
public abstract class AppDatabase extends RoomDatabase {
public static AppDatabase mDatabase;
public abstract UserDao userDao();
public static AppDatabase getAppDatabase(Context context) {
if (mDatabase == null) {
synchronized (AppDatabase.class) {
if (mDatabase == null) {
mDatabase = Room.databaseBuilder(context.getApplicationContext(),
AppDatabase.class, "word_database")
// Wipes and rebuilds instead of migrating
// if no Migration object.
// Migration is not part of this practical.
.fallbackToDestructiveMigration()
.build();
}
}
}
return mDatabase;
}
}
使用上面的代码,我收到以下错误:
error: incompatible types: SupportSQLiteDatabase cannot be converted to AppDatabase
我的代码有什么问题?
答案 0 :(得分:0)
该错误是由于AppDatabase类的对象的名称引起的。将其重命名为mDatabase以外的任何对象名称,然后它将正常运行。
如果检查AppDatabase_Impl.java,您将注意到mDatabase有错误。这是因为SupportSQLiteDatabase.java具有对象名称mDatabase,该名称将被放置在AppDatabase中的对象名称覆盖。