SqlCeException in windows phone 7 - windows-phone-7

Question

I have been using Microsoft Live API for uploading & downloading database. but after downloading or uploading if i tried to access the database in anyway my app gives SqlCeException Unhandled & exits.
If i restart the app before accessing database it doesn't give any errors so for now the solution is
Restart the application
This is my code
IsolatedStorageFileStream fileStream = null;
private void Upload_Click(object sender, RoutedEventArgs e)
{
if (client == null || client.Session == null)
{
MessageBox.Show("You Must Sign In First.");
}
else
{
if (MessageBox.Show("Are You Sure? This Will Overwrite Your Old Backup File!", "Backup?", MessageBoxButton.OKCancel) == MessageBoxResult.OK)
{
UploadDatabase();
}
}
}
public void UploadDatabase()
{
if (SDFolderID != string.Empty)
{
WLInfo.Text = "Uploading Backup...";
this.client.UploadCompleted += new EventHandler<LiveOperationCompletedEventArgs>(ISFile_UploadCompleted);
try
{
using (IsolatedStorageFile store = IsolatedStorageFile.GetUserStoreForApplication())
{
fileStream = store.OpenFile("DB.sdf", FileMode.Open, FileAccess.Read);
client.UploadAsync(SDFolderID, "DB.sdf", fileStream, OverwriteOption.Overwrite);
WLInfo.Text = "Upload Complete.";
}
}
catch
{
WLInfo.Text = "Error: Restart Application.";
}
}
}
private void ISFile_UploadCompleted(object sender, LiveOperationCompletedEventArgs args)
{
if (args.Error == null)
{
client = new LiveConnectClient(session);
client.GetCompleted += new EventHandler<LiveOperationCompletedEventArgs>(GetFiles_GetCompleted);
client.GetAsync(SDFolderID + "/files");
}
else
{
this.WLInfo.Text = "Error Uploading Backup File.";
}
fileStream.Close();
}
void GetFiles_GetCompleted(object sender, LiveOperationCompletedEventArgs e)
{
List<object> data = (List<object>)e.Result["data"];
foreach (IDictionary<string, object> content in data)
{
if (((string)content["name"]).Equals(FileName))
{
FileID = (string)content["id"];
}
}
if (FileID != null)
{
WLInfo.Text = "Backup Found On Sky Drive.";
}
else
{
WLInfo.Text = "Backup Not Found On Sky Drive.";
}
}

Answer 1

I'm guessing it's probably of a Stream not properly closed so your database file is still locked. When you upload or download your database file make sure you use the using statement on all disposable object so that all the Stream are properly disposed automatically
In your code fileStream is not disposed which is probably what is causing the problem (you should "save" this variable in a local filed and call dispose on it in ISFile_UploadCompleted).
Also when if you use using there is no need to call dispose on the object (no need to have store.Dispose();, it's automatically done when you go out of the using scope)