Funda i-INTERNET_OPTION_PROXY ku-WinINet nge-buffer ye-C# enosayizi

I-INTERNET_PROXY_INFO iqukethe uhlobo lokufinyelela lwe-DWORD kanye nama-pointer amabili womucu. Umbuzo womdabu udinga futhi isikhala se-buffer esanele sedatha yayo ye-proxy; i-Marshal.SizeOf yesakhiwo esincane esilawulwayo akusiyo i-buffer yomphumela ephelele yobude obushintshayo.

Umsizi wokuhambisana we-desktop ungasebenzisa indawo yokungena ye-ANSI futhi akope imicu ngaphambi kokukhulula leyo buffer yombuzo:

static class WinInetProxy
{
    [System.Runtime.InteropServices.StructLayout(
        System.Runtime.InteropServices.LayoutKind.Sequential)]
    struct ProxyInfo
    {
        public uint AccessType;
        public IntPtr Proxy;
        public IntPtr Bypass;
    }

    [System.Runtime.InteropServices.DllImport(
        "wininet.dll", EntryPoint = "InternetQueryOptionA",
        SetLastError = true)]
    [return: System.Runtime.InteropServices.MarshalAs(
        System.Runtime.InteropServices.UnmanagedType.Bool)]
    static extern bool Query(
        IntPtr handle, uint option, IntPtr buffer, ref uint size);

    public static (uint Type, string Proxy, string Bypass) Read()
    {
        uint size = 0;
        Query(IntPtr.Zero, 38, IntPtr.Zero, ref size);
        int error = System.Runtime.InteropServices.Marshal.GetLastWin32Error();
        if (error != 122 || size == 0)
            throw new System.ComponentModel.Win32Exception(error);

        IntPtr buffer = System.Runtime.InteropServices.Marshal
            .AllocHGlobal(checked((int)size));
        try
        {
            if (!Query(IntPtr.Zero, 38, buffer, ref size))
                throw new System.ComponentModel.Win32Exception(
                    System.Runtime.InteropServices.Marshal.GetLastWin32Error());
            var value = System.Runtime.InteropServices.Marshal
                .PtrToStructure<ProxyInfo>(buffer);
            return (value.AccessType,
                System.Runtime.InteropServices.Marshal.PtrToStringAnsi(value.Proxy) ?? "",
                System.Runtime.InteropServices.Marshal.PtrToStringAnsi(value.Bypass) ?? "");
        }
        finally
        {
            System.Runtime.InteropServices.Marshal.FreeHGlobal(buffer);
        }
    }
}

38 yi-INTERNET_OPTION_PROXY; 122 yi-ERROR_INSUFFICIENT_BUFFER. Ukushaya kokuqala kuthola inani lamabhayithi adingekayo, futhi okwesibili kugcwalisa leso sabelo. Uma umphumela ukhula phakathi kokushaya, kubikwa ukwehluleka kwesibili esikhundleni sokufunda i-buffer encane kakhulu.

Gcina i-AccessType njenge-uint. Kuqhubekeko lwe-64-bit ihlala iyi-DWORD ye-32-bit, kuyilapho izinkambu ze-pointer zikhula ngokuhambisana nesakhiwo senqubo. Ukuhlelwa okulandelanayo okuvamile kunikeza ukuqondanisa okufanele.

Lesi sibonelo sikhuluma nge-buffer yomphumela yokukhetha 38. Ungasebenzisi iphethini yobunikazi bayo ngobumpumputhe ku-INTERNET_OPTION_PER_CONNECTION_OPTION, okukhethwa kwayo kwemichu okubuyiswayo kudinga ukuhlanjululwa okuhlukile okubhaliwe.

Umphumela uchaza ukulungiselelwa kwe-WinINet ebangeni lesibambi esikhethiwe. Akusona isinqumo se-PAC sanoma iyiphi i-URL noma umbiko womzila wangempela weso sonke isiphequluli. Uma umucu we-proxy obuyiswayo uyi-balazwe eliqondene ne-protocol, gcina leso sakhiwo esikhundleni sokusithatha njengendawo eyodwa yokuphela. I-WinINet iyi-API ye-desktop; izinhlelo zokusebenza zensizakalo zidinga ukuhlelwa kwazo kwe-WinHTTP okusekelwayo.