I created my first project in ASP.net. I created the ASP.Net Web Application project and selected Empty. I have created many pages in it, also have some pages which fetch data from my SQL server database. Now I am required to fetch data from Web API, how can I do this? I looked up videos and other help documents, and I see many results showing how to get data for web forms applications, or MVC or web API, but not what I am looking for. Can someone please guide me on how to accomplish this?
1 Answers
If the Web API that you are calling does not need any key then following is the sample that accesses yahoo finance API that returns JSON and the data is then put into data table. I have not shown here some JSON classes just for the simplicity. These are getting used when i parse the JSON output from API. If you need an example for API with key, you will have to add it as one of the attribute in the URL. Let me know if you need example with API key as well.
public DataTable GetQuote(string symbol)
{
DataTable resultDataTable = null;
try
{
string webservice_url = "";
WebResponse wr;
Stream receiveStream = null;
StreamReader reader = null;
//DataRow r;
//https://query1.finance.yahoo.com/v7/finance/chart/HDFC.BO?range=1m&interval=1m&indicators=quote×tamp=true
webservice_url = string.Format(StockManager.urlGlobalQuote, symbol);
Uri url = new Uri(webservice_url);
var webRequest = WebRequest.Create(url);
webRequest.Method = "GET";
webRequest.ContentType = "application/json";
wr = webRequest.GetResponseAsync().Result;
receiveStream = wr.GetResponseStream();
reader = new StreamReader(receiveStream);
resultDataTable = getQuoteTableFromJSON(reader.ReadToEnd(), symbol);
reader.Close();
if (receiveStream != null)
receiveStream.Close();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
if (resultDataTable != null)
{
resultDataTable.Clear();
resultDataTable.Dispose();
}
resultDataTable = null;
}
return resultDataTable;
}
public DataTable getQuoteTableFromJSON(string record, string symbol)
{
DataTable resultDataTable = null;
if (record.ToUpper().Contains("NOT FOUND"))
{
return null;
}
DateTime myDate;
double close;
double high;
double low;
double open;
int volume;
double change;
double changepercent;
double prevclose;
//double adjusetedClose = 0.00;
//string formatedDate;
var errors = new List<string>();
try
{
Root myDeserializedClass = JsonConvert.DeserializeObject<Root>(record, new JsonSerializerSettings
{
NullValueHandling = NullValueHandling.Ignore,
DefaultValueHandling = DefaultValueHandling.Populate,
Error = delegate (object sender, Newtonsoft.Json.Serialization.ErrorEventArgs args)
{
errors.Add(args.ErrorContext.Error.Message);
args.ErrorContext.Handled = true;
//args.ErrorContext.Handled = false;
}
//Converters = { new IsoDateTimeConverter() }
});
Chart myChart = myDeserializedClass.chart;
Result myResult = myChart.result[0];
Meta myMeta = myResult.meta;
Indicators myIndicators = myResult.indicators;
//this will be typically only 1 row and quote will have list of close, high, low, open, volume
Quote myQuote = myIndicators.quote[0];
//this will be typically only 1 row and adjClose will have list of adjClose
//Adjclose myAdjClose = null;
//if (bIsDaily)
//{
// myAdjClose = myIndicators.adjclose[0];
//}
if (myResult.timestamp != null)
{
resultDataTable = new DataTable();
resultDataTable.Columns.Add("Symbol", typeof(string));
resultDataTable.Columns.Add("Open", typeof(decimal));
resultDataTable.Columns.Add("High", typeof(decimal));
resultDataTable.Columns.Add("Low", typeof(decimal));
resultDataTable.Columns.Add("Price", typeof(decimal));
resultDataTable.Columns.Add("Volume", typeof(int));
resultDataTable.Columns.Add("latestDay", typeof(DateTime));
resultDataTable.Columns.Add("previousClose", typeof(decimal));
resultDataTable.Columns.Add("change", typeof(decimal));
resultDataTable.Columns.Add("changePercent", typeof(decimal));
for (int i = 0; i < myResult.timestamp.Count; i++)
{
if ((myQuote.close[i] == null) && (myQuote.high[i] == null) && (myQuote.low[i] == null) && (myQuote.open[i] == null)
&& (myQuote.volume[i] == null))
{
continue;
}
//myDate = new DateTime(1970, 1, 1, 0, 0, 0, 0).AddSeconds(myResult.timestamp[i]).ToLocalTime();
myDate = convertUnixEpochToLocalDateTime(myResult.timestamp[i], myMeta.timezone);
//myDate = new DateTime(1970, 1, 1, 0, 0, 0, 0).AddSeconds(myResult.timestamp[i]);
//string formatedDate = myDate.ToString("dd-MM-yyyy");
//formatedDate = myDate.ToString("yyyy-dd-MM");
//myDate = System.Convert.ToDateTime(myResult.timestamp[i]);
//if all are null do not enter this row
if (myQuote.close[i] == null)
{
close = 0.00;
}
else
{
//close = (double)myQuote.close[i];
close = System.Convert.ToDouble(string.Format("{0:0.00}", myQuote.close[i]));
}
if (myQuote.high[i] == null)
{
high = 0.00;
}
else
{
//high = (double)myQuote.high[i];
high = System.Convert.ToDouble(string.Format("{0:0.00}", myQuote.high[i]));
}
if (myQuote.low[i] == null)
{
low = 0.00;
}
else
{
//low = (double)myQuote.low[i];
low = System.Convert.ToDouble(string.Format("{0:0.00}", myQuote.low[i]));
}
if (myQuote.open[i] == null)
{
open = 0.00;
}
else
{
//open = (double)myQuote.open[i];
open = System.Convert.ToDouble(string.Format("{0:0.00}", myQuote.open[i]));
}
if (myQuote.volume[i] == null)
{
volume = 0;
}
else
{
volume = (int)myQuote.volume[i];
}
prevclose = System.Convert.ToDouble(string.Format("{0:0.00}", myMeta.chartPreviousClose));
change = close - prevclose;
changepercent = (change / prevclose) * 100;
change = System.Convert.ToDouble(string.Format("{0:0.00}", change));
changepercent = System.Convert.ToDouble(string.Format("{0:0.00}", changepercent));
resultDataTable.Rows.Add(new object[] {
symbol,
Math.Round(open, 4),
Math.Round(high, 4),
Math.Round(low, 4),
Math.Round(close, 4),
volume,
myDate,
Math.Round(prevclose, 4),
Math.Round(change, 4),
Math.Round(changepercent, 4)
//adjusetedClose
});
}
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
if (resultDataTable != null)
{
resultDataTable.Clear();
resultDataTable.Dispose();
}
resultDataTable = null;
}
return resultDataTable;
}Related