无法在 xamarin 中创建表 sqlite 表（仅限设备）模拟器工作正常答案

【问题标题】：Unable to create table sqlite table in xamarin(Device only) Emulator works fine无法在 xamarin 中创建表 sqlite 表（仅限设备）模拟器工作正常
【发布时间】：2019-02-01 13:15:43
【问题描述】：

我正在使用 SQLite-net-PCL nugget 我无法使用此模型创建表。我在这里遇到了这个异常。

内部异常条件：

  at SQLite.SQLite3.Prepare2 (SQLitePCL.sqlite3 db, System.String query) [0x0001b] in <eaa146ee868043e287f5507c8701ad9e>:0 
02-01 18:18:23.620 I/mono-stdout( 3072):   at SQLite.SQLite3.Prepare2 (SQLitePCL.sqlite3 db, System.String query) [0x0001b] in <eaa146ee868043e287f5507c8701ad9e>:0 
  at SQLite.SQLiteCommand.Prepare () [0x00011] in <eaa146ee868043e287f5507c8701ad9e>:0 
02-01 18:18:23.625 I/mono-stdout( 3072):   at SQLite.SQLiteCommand.Prepare () [0x00011] in <eaa146ee868043e287f5507c8701ad9e>:0 
  at SQLite.SQLiteCommand.ExecuteNonQuery () [0x00030] in <eaa146ee868043e287f5507c8701ad9e>:0 
02-01 18:18:23.627 I/mono-stdout( 3072):   at SQLite.SQLiteCommand.ExecuteNonQuery () [0x00030] in <eaa146ee868043e287f5507c8701ad9e>:0 
  at SQLite.SQLiteConnection.Execute (System.String query, System.Object[] args) [0x00039] in <eaa146ee868043e287f5507c8701ad9e>:0 
02-01 18:18:23.629 I/mono-stdout( 3072):   at SQLite.SQLiteConnection.Execute (System.String query, System.Object[] args) [0x00039] in <eaa146ee868043e287f5507c8701ad9e>:0 
  at SQLite.SQLiteConnection.MigrateTable (SQLite.TableMapping map, System.Collections.Generic.List`1[T] existingCols) [0x000ae] in <eaa146ee868043e287f5507c8701ad9e>:0 
02-01 18:18:23.631 I/mono-stdout( 3072):   at SQLite.SQLiteConnection.MigrateTable (SQLite.TableMapping map, System.Collections.Generic.List`1[T] existingCols) [0x000ae] in <eaa146ee868043e287f5507c8701ad9e>:0 
  at SQLite.SQLiteConnection.CreateTable (System.Type ty, SQLite.CreateFlags createFlags) [0x0013e] in <eaa146ee868043e287f5507c8701ad9e>:0 
02-01 18:18:23.632 I/mono-stdout( 3072):   at SQLite.SQLiteConnection.CreateTable (System.Type ty, SQLite.CreateFlags createFlags) [0x0013e] in <eaa146ee868043e287f5507c8701ad9e>:0 
  at SQLite.SQLiteConnection.CreateTable[T] (SQLite.CreateFlags createFlags) [0x00000] in <eaa146ee868043e287f5507c8701ad9e>:0 
02-01 18:18:23.634 I/mono-stdout( 3072):   at SQLite.SQLiteConnection.CreateTable[T] (SQLite.CreateFlags createFlags) [0x00000] in <eaa146ee868043e287f5507c8701ad9e>:0 
  at SQLite.SQLiteAsyncConnection+<>c__DisplayClass31_0`1[T].<CreateTableAsync>b__0 (SQLite.SQLiteConnectionWithLock conn) [0x00000] in <eaa146ee868043e287f5507c8701ad9e>:0 
02-01 18:18:23.636 I/mono-stdout( 3072):   at SQLite.SQLiteAsyncConnection+<>c__DisplayClass31_0`1[T].<CreateTableAsync>b__0 (SQLite.SQLiteConnectionWithLock conn) [0x00000] in <eaa146ee868043e287f5507c8701ad9e>:0 
  at SQLite.SQLiteAsyncConnection+<>c__DisplayClass29_0`1[T].<WriteAsync>b__0 () [0x00013] in <eaa146ee868043e287f5507c8701ad9e>:0 
02-01 18:18:23.638 I/mono-stdout( 3072):   at SQLite.SQLiteAsyncConnection+<>c__DisplayClass29_0`1[T].<WriteAsync>b__0 () [0x00013] in <eaa146ee868043e287f5507c8701ad9e>:0 
  at System.Threading.Tasks.Task`1[TResult].InnerInvoke () [0x0000f] in <d4a23bbd2f544c30a48c44dd622ce09f>:0 
02-01 18:18:23.640 I/mono-stdout( 3072):   at System.Threading.Tasks.Task`1[TResult].InnerInvoke () [0x0000f] in <d4a23bbd2f544c30a48c44dd622ce09f>:0 
  at System.Threading.Tasks.Task.Execute () [0x00000] in <d4a23bbd2f544c30a48c44dd622ce09f>:0 02-01 18:18:23.641 I/mono-

public class Setting
{
    [PrimaryKey]
   //  public int id { get; set; }
    public int UserID { get; set; }
    public string Email { get; set; }
    public bool AutoUpload { get; set; }
    public bool UseCellularData { get; set; }
    public int MaxStoredRecordings { get; set; }
    public string UnitPreference { get; set; }
    public string DateFormatPreference { get; set; }
    public string TimeFormat { get; set; }
    public string SerialNo { get; set; }
}

实际例外：

我遇到了这个异常

System.AggregateException: One or more errors occurred.D/ConnectivityManager.CallbackHandler(  487): CM callback handler got msg 524294
02-01 19:06:50.907 I/mono-stdout(  487):   at System.Threading.Tasks.Task.ThrowIfExceptional (System.Boolean includeTaskCanceledExceptions) [0x00011] in <d4a23bbd2f544c30a48c44dd622ce09f>:0 
  at System.Threading.Tasks.Task.ThrowIfExceptional (System.Boolean includeTaskCanceledExceptions) [0x00011] in <d4a23bbd2f544c30a48c44dd622ce09f>:0 
  at System.Threading.Tasks.Task.Wait (System.Int32 millisecondsTimeout, System.Threading.CancellationToken cancellationToken) [0x00043] in <d4a23bbd2f544c30a48c44dd622ce09f>:0 02-01 19:06:50.917 I/mono-stdout(  487):   at System.Threading.Tasks.Task.Wait (System.Int32 millisecondsTimeout, System.Threading.CancellationToken cancellationToken) [0x00043] in <d4a23bbd2f544c30a48c44dd622ce09f>:0 at System.Threading.Tasks.Task.Wait () [0x00000] in <d4a23bbd2f544c30a48c44dd622ce09f>:0 
02-01 19:06:50.919 I/mono-stdout(  487):   at System.Threading.Tasks.Task.Wait () [0x00000] in <d4a23bbd2f544c30a48c44dd622ce09f>:0 
  at Feelix.Storage.DatabaseManager..ctor (System.String dbPath) [0x0003c] in D:\22\developer branch\Feelix\Feelix\Feelix\Storage\DatabaseManager.cs:45 
02-01 19:06:50.921 I/mono-stdout(  487):   at Feelix.Storage.DatabaseManager..ctor (System.String dbPath) [0x0003c] in D:\22\developer branch\Feelix\Feelix\Feelix\Storage\DatabaseManager.cs:45 
Thread finished: <Thread Pool> #2
The thread 0x2 has exited with code 0 (0x0).

我的桌子

 database = new SQLiteAsyncConnection(dbPath);
            database.CreateTableAsync<Patient>().Wait();
            database.CreateTableAsync<User>().Wait()
            database.CreateTableAsync<Setting>().Wait();
            database.CreateTableAsync<DeviceSessionDB>().Wait();
            database.CreateTableAsync<DeviceSessionRecordingsDB>().Wait();

除设置页表外，所有表均创建成功。

【问题讨论】：

您是否要更改现有表？
你能显示实际的异常信息和代码吗？
不，我不会改变这张桌子@SushiHangover
嗨@Crowcoder，我遇到了这个异常
在您的 catch 块中 flatten the aggregate exception 并使用异常消息更新问题。

标签： c# sqlite xamarin xamarin.forms

【解决方案1】：

不确定这是否能解决问题，但我使用异步方法而不是 Wait() 创建表。下面是我使用您的代码的方法（我删除了异步锁定代码以使其更简单）：

public class Repo {
    //set up 'database' variable

    public Repo() {
        CreateTablesAsync()
    }

    private async void CreateTablesAsync() {
        await database.CreateTableAsync<Patient>().ConfigureAwait(false);
        await database.CreateTableAsync<User>().ConfigureAwait(false);
        await database.CreateTableAsync<Setting>().ConfigureAwait(false);
        await database.CreateTableAsync<DeviceSessionDB>().ConfigureAwait(false);
        await database.CreateTableAsync<DeviceSessionRecordingsDB>().ConfigureAwait(false);
    }
}

【讨论】：