private string GetTextFromCommonDialog(IntPtr hWnd, uint msg)
{
string str = null;
IntPtr buffer = Marshal.AllocCoTaskMem(2 * InteropUtil.NumberOfFileChars);
try
{
InteropUtil.SendMessageIntPtr(hWnd, msg, new IntPtr(InteropUtil.NumberOfFileChars), buffer);
var chars = new char[InteropUtil.NumberOfFileChars];
Marshal.Copy(buffer, chars, 0, chars.Length);
int firstZeroTerm = ((IList)chars).IndexOf('\0');
if (firstZeroTerm >= 0 && firstZeroTerm <= chars.Length - 1)
{
str = new string(chars, 0, firstZeroTerm);
}
}
finally
{
Marshal.FreeCoTaskMem(buffer);
}
return(str);
}