Pregunta
¿Cuál es la mejor manera de emitir un http get en VB.net?Quiero obtener el resultado de una petición como http://api.hostip.info/?ip=68.180.206.184
Solución
En VB.NET:
Dim webClient As New System.Net.WebClient
Dim result As String = webClient.DownloadString("http://api.hostip.info/?ip=68.180.206.184")
En C#:
System.Net.WebClient webClient = new System.Net.WebClient();
string result = webClient.DownloadString("http://api.hostip.info/?ip=68.180.206.184");
Otros consejos
Puede utilizar la clase HttpWebRequest para realizar una petición y recuperar una respuesta de una determinada URL.Usted va a utilizar como:
Try
Dim fr As System.Net.HttpWebRequest
Dim targetURI As New Uri("http://whatever.you.want.to.get/file.html")
fr = DirectCast(HttpWebRequest.Create(targetURI), System.Net.HttpWebRequest)
If (fr.GetResponse().ContentLength > 0) Then
Dim str As New System.IO.StreamReader(fr.GetResponse().GetResponseStream())
Response.Write(str.ReadToEnd())
str.Close();
End If
Catch ex As System.Net.WebException
'Error in accessing the resource, handle it
End Try
HttpWebRequest es detallada en: http://msdn.microsoft.com/en-us/library/system.net.httpwebrequest.aspx
Una segunda opción es utilizar la clase WebClient, esto proporciona un fácil de usar interfaz para la descarga de los recursos de la web, pero no es tan flexible como HttpWebRequest:
Sub Main()
'Address of URL
Dim URL As String = http://whatever.com
' Get HTML data
Dim client As WebClient = New WebClient()
Dim data As Stream = client.OpenRead(URL)
Dim reader As StreamReader = New StreamReader(data)
Dim str As String = ""
str = reader.ReadLine()
Do While str.Length > 0
Console.WriteLine(str)
str = reader.ReadLine()
Loop
End Sub
Más info en el webclient se puede encontrar en: http://msdn.microsoft.com/en-us/library/system.net.webclient.aspx
El uso de la WebRequest clase
Esto es para obtener una imagen:
Try
Dim _WebRequest As System.Net.WebRequest = Nothing
_WebRequest = System.Net.WebRequest.Create(http://api.hostip.info/?ip=68.180.206.184)
Catch ex As Exception
Windows.Forms.MessageBox.Show(ex.Message)
Exit Sub
End Try
Try
_NormalImage = Image.FromStream(_WebRequest.GetResponse().GetResponseStream())
Catch ex As Exception
Windows.Forms.MessageBox.Show(ex.Message)
Exit Sub
End Try
La forma más fácil es System.Net.WebClient.DownloadFile
o DownloadString
.
Usted debe tratar de la HttpWebRequest clase.
Intente esto:
WebRequest request = WebRequest.CreateDefault(RequestUrl);
request.Method = "GET";
WebResponse response;
try { response = request.GetResponse(); }
catch (WebException exc) { response = exc.Response; }
if (response == null)
throw new HttpException((int)HttpStatusCode.NotFound, "The requested url could not be found.");
using(StreamReader reader = new StreamReader(response.GetResponseStream())) {
string requestedText = reader.ReadToEnd();
// do what you want with requestedText
}
Lo siento por el C#, sé que usted pidió para VB, pero yo no tenía tiempo para convertir.
Public Function getLoginresponce(ByVal email As String, ByVal password As String) As String
Dim requestUrl As String = "your api"
Dim request As HttpWebRequest = TryCast(WebRequest.Create(requestUrl), HttpWebRequest)
Dim response As HttpWebResponse = TryCast(request.GetResponse(), HttpWebResponse)
Dim dataStream As Stream = response.GetResponseStream()
Dim reader As New StreamReader(dataStream)
Dim responseFromServer As String = reader.ReadToEnd()
Dim result = responseFromServer
reader.Close()
response.Close()
Return result
End Function