Get currency exchange rates using exchange rate API in ASP.Net

Hi nauna,

Check this example. Now please take its reference and correct your code.

HTML

<asp:TextBox runat="server" ID="txtRate" AutoPostBack="true" OnTextChanged="TextChanged" /><br />
<asp:Label ID="lblValue" runat="server" />

Code

C#

protected void TextChanged(object sender, EventArgs e)
{
    string json = (new System.Net.WebClient()).DownloadString("https://api.exchangeratesapi.io/latest");
    System.Web.Script.Serialization.JavaScriptSerializer js = new System.Web.Script.Serialization.JavaScriptSerializer();
    KeyValuePair<string, object> rates = js.Deserialize<Dictionary<string, object>>(json)
                                        .Where(x => x.Key == "rates").FirstOrDefault();
    KeyValuePair<string, object> keyValue = (rates.Value as Dictionary<string, object>)
                                            .Where(x => x.Key == txtRate.Text).FirstOrDefault();
    if (keyValue.Value != null)
    {
        lblValue.Text = keyValue.Value.ToString();
    }
}

VB.Net

Protected Sub TextChanged(ByVal sender As Object, ByVal e As EventArgs)
    Dim json As String = (New System.Net.WebClient()).DownloadString("https://api.exchangeratesapi.io/latest")
    Dim js As Script.Serialization.JavaScriptSerializer = New Script.Serialization.JavaScriptSerializer()
    Dim rates As KeyValuePair(Of String, Object) = js.Deserialize(Of Dictionary(Of String, Object))(json) _
                                                   .Where(Function(x) x.Key = "rates").FirstOrDefault()
    Dim keyValue As KeyValuePair(Of String, Object) = TryCast(rates.Value, Dictionary(Of String, Object)) _
                                                      .Where(Function(x) x.Key = txtRate.Text).FirstOrDefault()
    If keyValue.Value IsNot Nothing Then
        lblValue.Text = keyValue.Value.ToString()
    End If
End Sub

Screenshot