/// <summary>
/// Reopens the connection to the database server asynchronously.
/// </summary>
/// <param name="callback">The callback method.</param>
/// <param name="userState">The user state.</param>
/// <returns>The asynchronous result.</returns>
public override IAsyncResult Reopen(DbServerCallback callback, object userState = null)
{
// Create a new asynchrounous state for this operation.
DbServerAsyncState asyncState = new DbServerAsyncState(this, userState);
// Begin open the connection asynchronously on the thread pool.
ThreadPool.QueueUserWorkItem((object state) =>
{
// Execute asynchronously on the thread pool.
try
{
// Reopen the connection.
this.Reopen();
}
catch (Exception exception)
{
// If an exception occurs, set the callback exception.
asyncState.Exception = new DbException("Reopening the connection to the database server \'{0}\' failed.".FormatWith(this.Name), exception);
}
// Complete the asynchronous operation.
asyncState.Complete();
// Call the callback method with the given state.
if (callback != null) callback(asyncState);
});
return asyncState;
}
/// <summary>
/// A callback function for when the removal operation completed, either successfully or unsuccessfully.
/// </summary>
/// <param name="state">The asynchronous state.</param>
private void OnRemoveComplete(DbServerAsyncState state)
{
// Execute the code on the UI thread.
this.Invoke(() =>
{
// Hide the message.
this.HideMessage();
// If the exception is not null, display an error message to the user.
if (state.Exception != null)
{
MessageBox.Show(
this,
state.Exception.Message,
"Database Server Removal Failed",
MessageBoxButtons.OK,
MessageBoxIcon.Error);
}
});
}
/// <summary>
/// A callback method called when a disconnection to a server has completed.
/// </summary>
/// <param name="asyncState">The asynchronous state.</param>
private void OnDisconnected(DbServerAsyncState asyncState)
{
// Execute the code on the UI thread.
this.Invoke(() =>
{
// Hide the connecting message.
this.HideMessage();
// Check if an exception occurred.
if (asyncState.Exception != null)
{
// If this a database exception.
if (asyncState.Exception.IsDb)
{
// Display a database error message.
MessageBox.Show(
this,
"Connecting to the database server \'{0}\' failed. {1}".FormatWith(asyncState.Server.Name, asyncState.Exception.DbMessage),
"Connecting to Database Failed",
MessageBoxButtons.OK,
MessageBoxIcon.Error
);
}
else
{
// Display a generic error message.
MessageBox.Show(
this,
"Connecting to the database server \'{0}\' failed. {1}".FormatWith(asyncState.Server.Name, asyncState.Exception.Message),
"Connecting to Database Failed",
MessageBoxButtons.OK,
MessageBoxIcon.Error
);
}
}
// Else, do nothing.
});
}
/// <summary>
/// A callback method called when changing the password of a server completed.
/// </summary>
/// <param name="asyncState"></param>
private void OnPasswordChangeCompleted(DbServerAsyncState asyncState)
{
// Execute the code on the UI thread.
this.Invoke(() =>
{
// Hide the connecting message.
this.HideMessage();
// Check if an exception occurred.
if (asyncState.Exception != null)
{
// If this a database exception.
if (asyncState.Exception.IsDb)
{
// Display a database error message.
MessageBox.Show(
this,
"Connecting to the database server \'{0}\' failed. {1}".FormatWith(asyncState.Server.Name, asyncState.Exception.DbMessage),
"Connecting to Database Failed",
MessageBoxButtons.OK,
MessageBoxIcon.Error
);
}
else
{
// Display a generic error message.
MessageBox.Show(
this,
"Connecting to the database server \'{0}\' failed. {1}".FormatWith(asyncState.Server.Name, asyncState.Exception.Message),
"Connecting to Database Failed",
MessageBoxButtons.OK,
MessageBoxIcon.Error
);
}
}
// Else, show a notification message.
else
{
MessageBox.Show(
this,
"The database server password has been changed successfully.",
"Server Password Changed",
MessageBoxButtons.OK,
MessageBoxIcon.Information);
}
});
}
/// <summary>
/// A callback method called when a connection to a server has completed.
/// </summary>
/// <param name="asyncState">The asynchronous state.</param>
private void OnConnected(DbServerAsyncState asyncState)
{
// Execute the code on the UI thread.
this.Invoke(() =>
{
// Enable the tool strip.
this.toolStrip.Enabled = true;
// Hide the connecting message.
this.HideMessage();
// Check if an exception occurred.
if (asyncState.Exception != null)
{
// If this a database exception.
if (asyncState.Exception.IsDb)
{
// Check the error type.
switch (asyncState.Exception.DbType)
{
case DbException.Type.LoginPasswordExpired:
if (DialogResult.Yes == MessageBox.Show(
this,
"The login password for the database server \'{0}\' has expired. Do you wish to change the password now?".FormatWith(asyncState.Server.Name),
"Login Password Expired",
MessageBoxButtons.YesNo,
MessageBoxIcon.Question,
MessageBoxDefaultButton.Button2
))
{
// Change password.
this.OnChangePassword(null, null);
}
break;
case DbException.Type.LoginPasswordMustChange:
if (DialogResult.Yes == MessageBox.Show(
this,
"To connect to the database server \'{0}\' you must change the password before the first login. Do you wish to change the password now?".FormatWith(asyncState.Server.Name),
"Must Change Password",
MessageBoxButtons.YesNo,
MessageBoxIcon.Question,
MessageBoxDefaultButton.Button2
))
{
// Change password.
this.OnChangePassword(null, null);
}
break;
default:
// Display an error message.
MessageBox.Show(
this,
"Connecting to the database server \'{0}\' failed. {1}".FormatWith(asyncState.Server.Name, asyncState.Exception.DbMessage),
"Connecting to Database Failed",
MessageBoxButtons.OK,
MessageBoxIcon.Error
);
break;
}
}
else
{
// Display an error message.
MessageBox.Show(
this,
"Connecting to the database server \'{0}\' failed. {1}".FormatWith(asyncState.Server.Name, asyncState.Exception.Message),
"Connecting to Database Failed",
MessageBoxButtons.OK,
MessageBoxIcon.Error
);
}
}
// Else, process the user state.
else
{
// If there exists a user asynchronous state.
if (asyncState.AsyncState != null)
{
// If the user state is an event handler, call that event handler.
if (asyncState.AsyncState is EventHandler)
{
// Get the event handler.
EventHandler handler = asyncState.AsyncState as EventHandler;
// Call the event handler.
handler(this, EventArgs.Empty);
}
}
}
});
}
