(VB.NET) Simple REST Example

Demonstrates a very simple RESTful API call to get a stock time series daily (quotes) from Alpha Vantage.

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim rest As New Chilkat.Rest

' Connect to the REST server.
Dim bTls As Boolean = True
Dim port As Integer = 443
Dim bAutoReconnect As Boolean = True
Dim success As Boolean = rest.Connect("www.alphavantage.co",port,bTls,bAutoReconnect)
If (success <> True) Then
    Debug.WriteLine(rest.LastErrorText)
    Exit Sub
End If


' Get a stock quote:
' Sending GET request to https://www.alphavantage.co/query?function=TIME_SERIES_DAILY&symbol=MSFT&apikey=my_api_key
success = rest.AddQueryParam("function","TIME_SERIES_DAILY")
success = rest.AddQueryParam("symbol","AAPL")
success = rest.AddQueryParam("apikey","my_api_key")
Dim responseJson As String = rest.FullRequestNoBody("GET","/query")
If (rest.LastMethodSuccess <> True) Then
    Debug.WriteLine(rest.LastErrorText)
    Exit Sub
End If


Debug.WriteLine(responseJson)

' Sample response:
' {
'     "Meta Data": {
'         "1. Information": "Daily Prices (open, high, low, close) and Volumes",
'         "2. Symbol": "AAPL",
'         "3. Last Refreshed": "2019-12-06",
'         "4. Output Size": "Compact",
'         "5. Time Zone": "US/Eastern"
'     },
'     "Time Series (Daily)": {
'         "2019-12-06": {
'             "1. open": "267.4800",
'             "2. high": "271.0000",
'             "3. low": "267.3000",
'             "4. close": "270.7100",
'             "5. volume": "25447644"
'         },
'         "2019-12-05": {
'             "1. open": "263.7900",
'             "2. high": "265.8900",
'             "3. low": "262.7300",
'             "4. close": "265.5800",
'             "5. volume": "18661343"
'         },
'         "2019-12-04": {
'             "1. open": "261.0700",
'             "2. high": "263.3100",
'             "3. low": "260.6800",
'             "4. close": "261.7400",
'             "5. volume": "16810388"
'         },
' ...
'         "2019-07-18": {
'             "1. open": "204.0000",
'             "2. high": "205.8800",
'             "3. low": "203.7000",
'             "4. close": "205.6600",
'             "5. volume": "18582161"
'         }
'     }
' }