private static INTERNET_PER_CONN_OPTION QueryOption(INTERNET_PER_CONN_OptionEnum optionValue)
{
INTERNET_PER_CONN_OPTION[] options = new INTERNET_PER_CONN_OPTION[1];
options[0].dwOption = (int)optionValue;
ExecuteAction(options, (optionList, size) =>
{
bool result = InternetQueryOption(IntPtr.Zero, INTERNET_OPTION.INTERNET_OPTION_PER_CONNECTION_OPTION, ref optionList, ref size);
if (result)
{
IntPtr current = optionList.pOptions;
for (int i = 0; i < options.Length; i++)
{
options[i] = (INTERNET_PER_CONN_OPTION)Marshal.PtrToStructure(current, typeof(INTERNET_PER_CONN_OPTION));
current = (IntPtr)((int)current + Marshal.SizeOf(options[i]));
}
}
return result;
});
INTERNET_PER_CONN_OPTION option = options[0];
return option;
}
public static void SetProxy(bool isProxyUsed, string proxyServer)
{
INTERNET_PER_CONN_OPTION[] options = new INTERNET_PER_CONN_OPTION[2];
options[0] = new INTERNET_PER_CONN_OPTION();
options[0].dwOption = (int)INTERNET_PER_CONN_OptionEnum.INTERNET_PER_CONN_FLAGS;
options[0].Value.dwValue = isProxyUsed ? (int)INTERNET_OPTION_PER_CONN_FLAGS.PROXY_TYPE_PROXY : (int)INTERNET_OPTION_PER_CONN_FLAGS.PROXY_TYPE_DIRECT;
options[1] = new INTERNET_PER_CONN_OPTION();
options[1].dwOption = (int)INTERNET_PER_CONN_OptionEnum.INTERNET_PER_CONN_PROXY_SERVER;
options[1].Value.pszValue = Marshal.StringToHGlobalAnsi(proxyServer);
ExecuteAction(options, (optionList, size) =>
{
IntPtr intPtrStruct = Marshal.AllocCoTaskMem(size);
Marshal.StructureToPtr(optionList, intPtrStruct, true);
try
{
return InternetSetOption(IntPtr.Zero, INTERNET_OPTION.INTERNET_OPTION_PER_CONNECTION_OPTION, intPtrStruct, size);
}
finally
{
Marshal.FreeCoTaskMem(intPtrStruct);
}
});
InternetSetOption(IntPtr.Zero, INTERNET_OPTION.INTERNET_OPTION_SETTINGS_CHANGED, IntPtr.Zero, 0);
InternetSetOption(IntPtr.Zero, INTERNET_OPTION.INTERNET_OPTION_REFRESH, IntPtr.Zero, 0);
}
private static void ExecuteAction(INTERNET_PER_CONN_OPTION[] options, Func<INTERNET_PER_CONN_OPTION_LIST, int, bool> action)
{
IntPtr buffer = Marshal.AllocCoTaskMem(options.Sum(item => Marshal.SizeOf(item)));
IntPtr current = buffer;
for (int i = 0; i < options.Length; i++)
{
Marshal.StructureToPtr(options[i], current, false);
current = (IntPtr)((int)current + Marshal.SizeOf(options[i]));
}
INTERNET_PER_CONN_OPTION_LIST optionList = new INTERNET_PER_CONN_OPTION_LIST();
optionList.pOptions = buffer;
optionList.Size = Marshal.SizeOf(optionList);
optionList.Connection = IntPtr.Zero;
optionList.OptionCount = options.Length;
optionList.OptionError = 0;
int size = Marshal.SizeOf(optionList);
try
{
if (!action(optionList, size))
{
throw new ApplicationException("WinInet: action failed!");
}
}
finally
{
Marshal.FreeCoTaskMem(buffer);
}
}