// method to save the coin to the database
public void AddNewCoin()
{
using (var db = new CoinWatchEntities())
{
// converting the image path to a byte array
byte[] byteImage = File.ReadAllBytes(FileName);
Coin.IMAGE = byteImage;
db.COINs.Add(Coin);
db.SaveChanges();
}
}
/// <summary>
/// this methid retrieves a list of names of the cion currently in the database
/// </summary>
/// <returns></returns>
public static List <COIN> GetCoins()
{
List <COIN> coinValues = new List <COIN>();
using (var db = new CoinWatchEntities())
{
var query = from coin in db.COINs
select coin;
foreach (var valCoin in query)
{
coinValues.Add(valCoin);
}
}
return(coinValues);
}
/// <summary>
/// this method retrieves the prices for the coins in the database
/// </summary>
/// <returns></returns>
public static async Task CallWebAPIAsync()
{
List <COIN> coinList = GetCoins();
int[] coinIds = new int[coinList.Count];
string cListString = null;
for (int i = 0; i < coinList.Count; i++)
{
// this appends the names of the coins to the string to be passed to the api call
cListString += coinList[i].COIN_NAME + ",";
// creates an array of CoinIds
coinIds[i] = coinList[i].COIN_ID;
}
// removes the last comma from the api string
String withoutLast = cListString.Substring(0, (cListString.Length - 1));
using (var client = new HttpClient())
{
// this is the address for web api call
client.BaseAddress = new Uri("https://min-api.cryptocompare.com/");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
//GET Method
// the api call
HttpResponseMessage response = await client.GetAsync("data/pricemulti?fsyms=" + withoutLast + "&tsyms=EUR");
// if there was a response and wa successfull
if (response.IsSuccessStatusCode)
{
// the string response
string s = await response.Content.ReadAsStringAsync();
// list for the coin prices
List <decimal> prices = new List <decimal>();
// regex to match the prices from the json string response
foreach (Match m in Regex.Matches(s, @"[0-9]+\.[0-9]+"))
{
// adding the prices to the list
prices.Add(Convert.ToDecimal(m.Value));
}
// loop through all the prices
for (int i = 0; i < prices.Count; i++)
{
// create a coin value object
COIN_VALUE coinValue = new COIN_VALUE()
{
COIN_ID = coinIds[i],
DATETIME = DateTime.Now,
COIN_VALUE1 = prices[i]
};
// save the new value to the database
using (var db = new CoinWatchEntities())
{
db.COIN_VALUE.Add(coinValue);
db.SaveChanges();
}
}
}
else
{
Console.WriteLine("Internal server Error");
}
}
}
