C# Signature:
[DllImport("userenv.dll", SetLastError=true)]
static extern bool CreateEnvironmentBlock( out IntPtr lpEnvironment, IntPtr hToken, bool bInherit );
VB Signature:
<DllImport("userenv.dll")> _
Public Shared Function CreateEnvironmentBlock(ByRef lpEnvironment As IntPtr, ByVal hToken As IntPtr, ByVal bInherit As Boolean) As Boolean
End Function
User-Defined Types:
None.
Alternative Managed API:
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Notes:
None.
Tips & Tricks:
Please add some!
Sample Code:
[DllImport("userenv.dll", SetLastError = true)]
internal static extern bool CreateEnvironmentBlock(ref IntPtr lpEnvironment, IntPtr hToken, bool bInherit);
/// <summary>
/// Create an environment
/// </summary>
/// <param name="token">The security token</param>
/// <param name="inherit">Inherit the environment from the calling process</param>
/// <returns>a dictionary that represents the environ</returns>
internal static Dictionary<string,string> CreateEnvironmentBlock(SecurityToken token, bool inherit) {
IntPtr env = IntPtr.Zero;
if (!CreateEnvironmentBlock(ref env, token, inherit)) {
int lastError = Marshal.GetLastWin32Error();
throw new System.ComponentModel.Win32Exception(lastError, "CreateEnvironmentBlock Error " + lastError);
}
Dictionary<String, String> userEnvironment = new Dictionary<string, string>();
try {
StringBuilder testData = new StringBuilder("");
unsafe {
short* start = (short*)env.ToPointer();
bool done = false;
short* current = start;
while (!done) {
if ((testData.Length > 0) && (*current == 0) && (current != start)) {
String data = testData.ToString();
int index = data.IndexOf('=');
if (index == -1) {
userEnvironment.Add(data, "");
} else if (index == (data.Length - 1)) {
userEnvironment.Add(data.Substring(0, index), "");
} else {
userEnvironment.Add(data.Substring(0, index), data.Substring(index + 1));
}
testData.Length = 0;
}
if ((*current == 0) && (current != start) && (*(current - 1) == 0)) {
done = true;
}
if (*current != 0) {
testData.Append((char)*current);
}
current++;
}
}
} finally {
DestroyEnvironmentBlock(env);
}
return userEnvironment;
}
/// <summary>
/// Create a byte array that represents the environment for
/// the different CreateProcess calls
/// </summary>
/// <param name="env">The input environment</param>
/// <returns>A byte array</returns>
private byte[] CreateEnvironment(Dictionary<string, string> env) {
MemoryStream ms = new MemoryStream();
StreamWriter w = new StreamWriter(ms, Encoding.Unicode);
w.Flush();
ms.Position = 0; //Skip any byte order marks to identify the encoding
Char nullChar = (char)0;
foreach (string k in env.Keys) {
w.Write("{0}={1}", k, env[k]);
w.Write(nullChar);
}
w.Write(nullChar);
w.Write(nullChar);
w.Flush();
ms.Flush();
byte[] data = ms.ToArray();
return data;
}
