IWinHttpRequest::Option property

Article
01/07/2021

The Option property sets or retrieves a Microsoft Windows HTTP Services (WinHTTP) option value.

This property is read/write.

Syntax

HRESULT put_Option(
  [in]          WinHttpRequestOption Option,
  [in]          VARIANT              Value
);

HRESULT get_Option(
  [in]          WinHttpRequestOption Option,
  [out, retval] VARIANT              *Value
);


vtOption = WinHttpRequest.Option
WinHttpRequest.Option = vtOption

Property value

A Variant value that contains the option value.

The Option parameter specifies the WinHttpRequestOption to set or retrieve.

Error codes

The return value is S_OK on success or an error value otherwise.

Remarks

Note

For Windows XP and Windows 2000, see the Run-Time Requirements section of the WinHTTP Start Page.

Examples

The following example shows how to set and view the user agent string option and view various other options.

#include <windows.h>
#include <stdio.h>
#include <objbase.h>

#include "httprequest.h"

#pragma comment(lib, "ole32.lib")
#pragma comment(lib, "oleaut32.lib")

// IID for IWinHttpRequest.
const IID IID_IWinHttpRequest =
{
    0x06f29373,
    0x5c5a,
    0x4b54,
    {0xb0, 0x25, 0x6e, 0xf1, 0xbf, 0x8a, 0xbf, 0x0e}
};

int main()
{
    // Variable for return value
    HRESULT    hr;

    // Initialize COM
    hr = CoInitialize( NULL );

    IWinHttpRequest *  pIWinHttpRequest = NULL;

    BSTR            bstrResponse = NULL;
    VARIANT         varFalse;
    VARIANT         varEmpty;
    VARIANT         varUserAgent;

    CLSID           clsid;

    VariantInit(&varFalse);
    V_VT(&varFalse)   = VT_BOOL;
    V_BOOL(&varFalse) = VARIANT_FALSE;

    VariantInit(&varEmpty);
    V_VT(&varEmpty) = VT_ERROR;

    varUserAgent.vt = VT_BSTR;
    varUserAgent.bstrVal = NULL;

    hr = CLSIDFromProgID(L"WinHttp.WinHttpRequest.5.1", &clsid);

    if (SUCCEEDED(hr))
    {
        hr = CoCreateInstance(clsid,
                              NULL,
                              CLSCTX_INPROC_SERVER,
                              IID_IWinHttpRequest,
                              (void **)&pIWinHttpRequest);
    }
    if (SUCCEEDED(hr))
    {
        // Open WinHttpRequest.
        BSTR bstrMethod  = SysAllocString(L"GET");
        BSTR bstrUrl = SysAllocString(L"https://microsoft.com");
        hr = pIWinHttpRequest->Open(bstrMethod,
                                    bstrUrl,
                                    varFalse);
        SysFreeString(bstrMethod);
        SysFreeString(bstrUrl);
    }
    if (SUCCEEDED(hr))
    {
        // Specify the user agent.
        varUserAgent.vt = VT_BSTR;
        varUserAgent.bstrVal =
                   SysAllocString(
                           L"A WinHttpRequest Example Program");

        //varUserAgent is L"A WinHttpRequest Example Program");
        hr = pIWinHttpRequest->put_Option(
                                 WinHttpRequestOption_UserAgentString,
                                 varUserAgent);
    }
    if (SUCCEEDED(hr))
    {    // Send Request.
        hr = pIWinHttpRequest->Send(varEmpty);
    }
    if (SUCCEEDED(hr))
    {
        // Get user agent string.
        hr = pIWinHttpRequest->get_Option(
                                 WinHttpRequestOption_UserAgentString,
                                 &varUserAgent);
        // Print response to console.
        wprintf(L"%s\n\n", varUserAgent.bstrVal);

        // Get URL.
        hr = pIWinHttpRequest->get_Option(WinHttpRequestOption_URL,
                                          &varUserAgent);
        // Print response to console.
        wprintf(L"%s\n\n", varUserAgent.bstrVal);

        // Get URL Code Page.
        hr = pIWinHttpRequest->get_Option(
                                     WinHttpRequestOption_URLCodePage,
                                     &varUserAgent);
        // Print response to console.
        wprintf(L"%u\n\n", varUserAgent.lVal);

        // Convert percent symbols to escape sequences.
        hr = pIWinHttpRequest->get_Option(
                              WinHttpRequestOption_EscapePercentInURL,
                              &varUserAgent);
        // Print response to console.
        wprintf(L"%s\n", varUserAgent.boolVal?L"True":L"False");
    }

    // Release memory.
    if (pIWinHttpRequest)
        pIWinHttpRequest->Release();
    if (bstrResponse)
        SysFreeString(bstrResponse);
    if (varUserAgent.bstrVal)
        SysFreeString(varUserAgent.bstrVal);

    CoUninitialize();
    return 0;
}

The following scripting example shows how to set and view options.

// Define the constants used by the option property.
WinHttpRequestOption_UserAgentString = 0;    // Name of the user agent
WinHttpRequestOption_URL = 1;                // Current URL
WinHttpRequestOption_URLCodePage = 2;        // Code page
WinHttpRequestOption_EscapePercentInURL = 3; // Convert percents 
                                             // in the URL

// Instantiate a WinHttpRequest object.
var WinHttpReq = new ActiveXObject("WinHttp.WinHttpRequest.5.1");

// Initialize an HTTP request.  
WinHttpReq.Open("GET", "https://www.microsoft.com", false);

// Send the HTTP request.
WinHttpReq.Send(); 

// Display the WinHTTP option values.
WScript.Echo( 'User agent:      '+
             WinHttpReq.Option(WinHttpRequestOption_UserAgentString));
WScript.Echo( 'URL:             '+
             WinHttpReq.Option(WinHttpRequestOption_URL));
WScript.Echo( 'Code page:       '+
             WinHttpReq.Option(WinHttpRequestOption_URLCodePage));
WScript.Echo( 'Escape percents: '+
          WinHttpReq.Option(WinHttpRequestOption_EscapePercentInURL));

Requirements

Requirement	Value
Minimum supported client	Windows XP, Windows 2000 Professional with SP3 [desktop apps only]
Minimum supported server	Windows Server 2003, Windows 2000 Server with SP3 [desktop apps only]
Redistributable	WinHTTP 5.0 and Internet Explorer 5.01 or later on Windows XP and Windows 2000.
IDL	HttpRequest.idl
Library	Winhttp.lib
DLL	Winhttp.dll

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