Xamarin.Android-使用SQLite.NET ORM创建多个数据库

Question

I had two databases in my app,which i created with the help of the SQLiteOpenHelper class.I decided to do away with the SQLiteOpenHelper and just create the databases using the SQLite component only.I have a databaseHandler class where i create the dbs and the tables.The problem is i can only seem to create one database.If i add a second database name to be created,i get a black screen on start up and then it crashes.It seems to me like the two dbs can't coexist in the same location.I'm not sure how to solve the issue though.

namespace com.Sample.Database
{
public class DatabaseHandler 
{

private string COMPANY_DATABASE_NAME;

private string USER_DATABASE_NAME = "User.db";
private string COMPANY_DATABASE_PATH;
private string USER_DATABASE_PATH;
private int databaseVersion = 3;
private SQLiteConnection companyDatabaseConnection;
private SQLiteConnection userDatabaseConnection;
private static DatabaseHandler dbHandler;
Context context;

//Constructor
private DatabaseHandler (Context context)
{
try
{
//this.COMPANY_DATABASE_NAME = "company" + "v" + this.databaseVersion + ".db";

    string dataDirectory = Environment.GetFolderPath (Environment.SpecialFolder.Personal);

     USER_DATABASE_PATH = System.IO.Path.Combine (dataDirectory, USER_DATABASE_NAME);

     COMPANY_DATABASE_PATH = System.IO.Path.Combine (dataDirectory, COMPANY_DATABASE_NAME);


    this.context = context;

}
catch(Exception ex)
{

            logTable.Exception (context, ex);

}


public static DatabaseHandler GetInstance(Context context)
   {
       if (dbHandler == null) {
             dbHandler = new DatabaseHandler (context);
      }

return dbHandler;
}
  public void initialize()
   {
       try
       {


    this.userDatabaseConnection = new SQLiteConnection(USER_DATABASE_PATH);

    this.userDatabaseConnection.CreateTable<UserTable> ();


    this.InsertData();

  //            this.companyDatabaseConnection = new SQLiteConnection     (COMPANY_DATABASE_PATH);
//
  //            this.companyDatabaseConnection .CreateTable<RecordsTable> ();

}
      catch(Exception e)
     {
                logTable.Exception (context, ex);


        }
   }

}

The crashing happens when i uncomment the line where i'm assigning a name to the company database:

//this.COMPANY_DATABASE_NAME = "company" + "v" + this.databaseVersion + ".db";

And gives me the following output:

[Mono] Assembly Ref addref GTI.Thales.Droid[0x7be12eb8] ->  SQLite[0x7c389c38]: 2
[Mono] Assembly Ref addref SQLite[0x7c389c38] -> mscorlib[0x73ac7ca8]: 10
[Mono] GC_OLD_BRIDGE num-objects 0 num_hash_entries 0 sccs size 0 init 0.00ms df1 0.00ms sort 0.00ms dfs2 0.00ms setup-cb 0.00ms free-data 0.00ms links   0/0/0/0 dfs passes 0/0
[Mono] GC_MINOR: (Nursery full) pause 147.43ms, total 147.98ms, bridge 0.34ms promoted 448K major 688K los 0K
[Mono] GC_OLD_BRIDGE num-objects 0 num_hash_entries 0 sccs size 0 init   0.00ms df1 0.00ms sort 0.00ms dfs2 0.00ms setup-cb 0.00ms free-data 0.00ms links   0/0/0/0 dfs passes 0/0
[Mono] GC_MINOR: (Nursery full) pause 141.11ms, total 141.66ms, bridge 0.21ms promoted 0K major 688K los 0K
[Mono] Warning: Degraded allocation.  Consider increasing nursery-size if the warning persists.

I already increased the nursery-size to 8 but i get the error still.

Answer 1

Try this:

this.COMPANY_DATABASE_NAME = "company" + "v" + this.databaseVersion.ToString() + ".db";