为什么在使用文件保存选择器创建sqlite数据库后无法连接到它?
以下代码用于使用文件保存选择器创建sqlite数据库。我必须先在app文件夹中创建数据库,然后复制到选择器文件。
var savePicker = new FileSavePicker
{
SuggestedStartLocation = PickerLocationId.DocumentsLibrary,
CommitButtonText = "Create new project"
};
savePicker.FileTypeChoices.Add("Data files", new List<string> { ".db" });
savePicker.DefaultFileExtension = ".db";
pickedFile = await savePicker.PickSaveFileAsync();
if (pickedFile != null)
{
Windows.Storage.AccessCache.StorageApplicationPermissions.FutureAccessList.Add(pickedFile);
var dbLocalPath = Path.Combine(ApplicationData.Current.LocalFolder.Path, "temp.db");
var db = new SQLiteAsyncConnection(dbLocalPath);
await db.CreateTableAsync<myTable>();
await db.ExecuteAsync("INSERT INTO myTable (Record) VALUES ('1')");
Debug.WriteLine(dbLocalPath);
var db2 = new SQLiteAsyncConnection(dbLocalPath);
var allRecords = await db2.QueryAsync<qvdb>("SELECT * FROM myTable");
var countRecords = allRecords.Any() ? allRecords.Count : 0;
Debug.WriteLine("There are " + countRecords); // this works
var localFile = await ApplicationData.Current.LocalFolder.GetFileAsync("temp.db");
if (localFile != null) await localFile.CopyAndReplaceAsync(pickedFile); // this works can open and see table in SQLite db browser
Debug.WriteLine(pickedFile.Path); // path is correct
var db3 = new SQLiteAsyncConnection(pickedFile.Path);
// ERROR //
// A first chance exception of type 'myApp.SQLiteException' occurred in myApp.exe
// A first chance exception of type 'myApp.SQLiteException' occurred in mscorlib.dll
// myApp.SQLiteException: Could not open database file: C:\Users\Gary\Documents\sql1.db (14)
// at myApp.SQLiteConnection..ctor(String databasePath) in c:\Users\Gary\Desktop\Current\myApp\SQLite.cs:line 108
// at myApp.SQLiteConnectionWithLock..ctor(SQLiteConnectionString connectionString) in c:\Users\Gary\Desktop\Current\myApp\SQLiteAsync.cs:line 441
// at myApp.SQLiteConnectionPool.Entry..ctor(SQLiteConnectionString connectionString) in c:\Users\Gary\Desktop\Current\myApp\SQLiteAsync.cs:line 373
// at myApp.SQLiteConnectionPool.GetConnection(SQLiteConnectionString connectionString) in c:\Users\Gary\Desktop\Current\myApp\SQLiteAsync.cs:line 406
// at myApp.SQLiteAsyncConnection.GetConnection() in c:\Users\Gary\Desktop\Current\myApp\SQLiteAsync.cs:line 44
// at myApp.SQLiteAsyncConnection.<>c__DisplayClass26`1.<QueryAsync>b__25() in c:\Users\Gary\Desktop\Current\myApp\SQLiteAsync.cs:line 255
// at System.Threading.Tasks.Task`1.InnerInvoke()
// at System.Threading.Tasks.Task.Execute()
//--- End of stack trace from previous location where exception was thrown ---
// at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
// at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
// at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
// at myApp.Pages.MainPage.<btnStartNew_Click>d__c3.MoveNext() in c:\Users\Gary\Desktop\Current\myApp\Pages\MainPage.xaml.cs:line 1587
}