public async Task SaveAsync()
{
try
{
await _phoneBookDataContext.SaveChangesAsync();
}
catch (DbEntityValidationException ex)
{
// Retrieve the error messages as a list of strings.
IEnumerable <string> errorMessages = ex.EntityValidationErrors
.SelectMany(x => x.ValidationErrors)
.Select(x => x.ErrorMessage);
// Join the list to a single string.
string fullErrorMessage = string.Join(" ", errorMessages);
// Combine the original exception message with the new one.
string exceptionMessage = string.Concat(ex.Message, "The validation errors are: ", fullErrorMessage);
// Throw a new DbEntityValidationException with the improved exception message.
throw new DbEntityValidationException(exceptionMessage, ex.EntityValidationErrors);
}
}
public async Task <OperationResult> CompleteAsync()
{
await context.SaveChangesAsync();
return(new OperationResult(true, "Request completed successfully"));
}