public async Task <bool> DeleteAsync(object id)
{
try
{
using (var db = new CurrencyDataContext())
{
var item = await db.CurrencyExchangeItems.FindAsync((Guid)id);
if (item != null)
{
var tracking = db.CurrencyExchangeItems.Remove(item);
await db.SaveChangesAsync();
return(tracking.State == EntityState.Deleted);
}
else
{
return(false);
}
}
}
catch (Exception e)
{
#if DEBUG
System.Diagnostics.Debug.WriteLine(e);
#endif
return(false);
}
}
public async Task <bool> UpdateAsync(CurrencyExchangeItem entity)
{
try
{
using (var db = new CurrencyDataContext())
{
var tracking = db.CurrencyExchangeItems.Update(entity);
await db.SaveChangesAsync();
return(tracking.State == EntityState.Modified);
}
}
catch (Exception e)
{
#if DEBUG
System.Diagnostics.Debug.WriteLine(e);
#endif
return(false);
}
}
public async Task <bool> UpdateRangeAsync(IEnumerable <CurrencyExchangeItem> entities)
{
try
{
using (var db = new CurrencyDataContext())
{
db.CurrencyExchangeItems.UpdateRange(entities);
await db.SaveChangesAsync();
return(true);
}
}
catch (Exception e)
{
#if DEBUG
System.Diagnostics.Debug.WriteLine(e);
#endif
return(false);
}
}
public async Task InitializeDatabaseAsync()
{
try
{
using (var db = new CurrencyDataContext())
{
db.Database.EnsureCreated();
// Add some default currencies for the first time.
var count = await db.CurrencyExchangeItems.CountAsync();
if (count == 0)
{
var targetCodes = new List <string> {
"USD", "CNY", "NZD", "AUD"
};
var targets = new List <CurrencyExchangeItem>();
targetCodes.ForEach(x =>
{
var item = new CurrencyExchangeItem(new CurrencyItem {
Code = "USD"
}, new CurrencyItem {
Code = x
}, ++count);
targets.Add(item);
});
await db.CurrencyExchangeItems.AddRangeAsync(targets);
await db.SaveChangesAsync();
}
}
}
catch (Exception e)
{
#if DEBUG
System.Diagnostics.Debug.WriteLine(e);
#endif
}
}