Convert a Widestring to an Ascii String?

[Marc]

Hello dear,

I have a string and every second char is a \0. Can I somehow convert it to a
normal string. Or may-be in the underlying code I am doing something wrong,
choose the wrong C# type?

This is my function I am trying to get right:

public static bool GetPrivateProfi leSectionAsCS(s tring appName, string
fileName, out string section)
{
section = null;
if (!System.IO.Fil e.Exists(fileNa me))
return false;
uint MAX_BUFFER = 32767;
IntPtr pReturnedString = Marshal.AllocCo TaskMem((int)MA X_BUFFER);
uint bytesReturned = GetPrivateProfi leSectionW(appN ame, pReturnedString ,
MAX_BUFFER, fileName);
if ((bytesReturned == MAX_BUFFER - 2) || (bytesReturned == 0))
return false;
System.Text.Str ingBuilder returnedString = new
System.Text.Str ingBuilder((int )bytesReturned) ;
//bytesReturned -1 to remove trailing \0
for (int i = 0; i < bytesReturned - 1; i++)
returnedString. Append((char)Ma rshal.ReadByte( new
IntPtr((uint)pR eturnedString + (uint)i)));
Marshal.FreeCoT askMem(pReturne dString);
section = returnedString. ToString();
section.Replace ("\0", ""); // this does not work
return true;
}

And this is how my string section looks like:

"N\0U\0M\0B\0E\ 0R\0=\0f\0t\0A\ 0u\0t\0o\0I\0n\ 0c\0\0\0S\0t\0a \0t\0u\0s\0N\0r \0=\0I\0D\0A\0\ 0\0P\0a\0t\0N\0 a\0m\0e\0=\0N\0 o\0t\0U\0s\0e\0 d\0\0\0D\0a\0t\ 0e\0=\0T\0x\0_\ 0D\0t\0T\0m\0<\ 0r\0e\0g\0e\0x\ 0>\0(\00\0[\01\0-\09\0]\0|\0[\01\02\0]\0[\00\0-\09\0]\0|\03\0[\00\01\0]\0)\0-\0(\00\0[\01\0-\09\0]\0|\01\0[\00\01\02\0]\0)\0-\0(\01\09\0|\02 \00\0)\0[\00\0-\09\0]\0[\00\0-\09\0]\0<\0/\0r\0e\0g\0e\0x \0>\0\0\0T\0i\0 m\0e\0=\0T\0x\0 _\0D\0t\0T\0m\0 <\0r\0e\0g\0e\0 x\0>\0[\00\0-\09\0]\0[\00\0-\09\0]\0:\0[\00\0-\09\0]\0[\00\0-\09\0]\0:\0[\00\0-\09\0]\0[\00\0-\09\0]\0<\0/\0r\0e\0g\0e\0x \0>\0\0\0V\0e\0 l\0d\0n\0a\0a\0 m\0=\0F\0i\0e\0 l\0d\0_\0L\0a\0 b\0e\0l\0+\0F\0 i\0e\0l\0d\0_\0 N\0a\0m\0e\0\0\ 0C\0l\0i\0n\0i\ 0c\0=\0T\0s\0t\ 0l\0\0\0B\0e\0a \0m\0N\0r\0=\0N \0o\0t\0U\0s\0e \0d\0\0\0S\0e\0 g\0m\0N\0r\0=\0 N\0o\0t\0U\0s\0 e\0d\0\0\0T\0e\ 0r\0m\0i\0n\0a\ 0t\0e\0=\0N\0o\ 0t\0U\0s\0e\0d\ 0\0\0D\0i\0a\0p \0h\0P\0r\0e\0s \0c\0=\0N\0o"

[Jon Skeet [C# MVP]]

On Nov 16, 12:34 pm, "Marc" <i...@ingcarlea se.nlwrote:

I have a string and every second char is a \0. Can I somehow convert it to a
normal string. Or may-be in the underlying code I am doing something wrong,
choose the wrong C# type?

I don't know the details of GetPrivateProfi leSectionW, but you may
well be able to get away with creating a byte[] instead of using
AllocCoTaskMem to return an IntPtr. You can then pass that byte[] into
GetPrivateProfi leSectionW and use Encoding.Unicod e afterwards.

Otherwise, use Marshal.Copy to copy the data into a byte[], and then
again you can use Encoding.Unicod e to turn the data into a string.

If these don't work, it's worth asking on the .interop newsgroup.

Jon

[Nicholas Paldino [.NET/C# MVP]]

Or, he could just use a definition of GetPrivateProvi deSection which
would marshal the string correctly. A declaration that uses bytes in the
parameter doesn't do any good.

The declaration should be:

[DllImport("kern el32.dll", CharSet=CharSet .Auto)]
static extern uint GetPrivateProfi leString(
string lpAppName,
string lpKeyName,
string lpDefault,
[In, Out] char[] lpReturnedStrin g,
uint nSize,
string lpFileName);

The use of the char array is to prevent the marshaling layer from not
sending back all of the characters in the string after finding the first
null character.

It makes it a lot easier than allocating the memory and whatnot (which
should have been placed in a try/finally block, in the case of an
exception).
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard. caspershouse.co m
"Jon Skeet [C# MVP]" <sk***@pobox.co mwrote in message
news:b3******** *************** ***********@41g 2000hsh.googleg roups.com...

On Nov 16, 12:34 pm, "Marc" <i...@ingcarlea se.nlwrote:

>I have a string and every second char is a \0. Can I somehow convert it
to a
normal string. Or may-be in the underlying code I am doing something
wrong,
choose the wrong C# type?

I don't know the details of GetPrivateProfi leSectionW, but you may
well be able to get away with creating a byte[] instead of using
AllocCoTaskMem to return an IntPtr. You can then pass that byte[] into
GetPrivateProfi leSectionW and use Encoding.Unicod e afterwards.

Otherwise, use Marshal.Copy to copy the data into a byte[], and then
again you can use Encoding.Unicod e to turn the data into a string.

If these don't work, it's worth asking on the .interop newsgroup.

Jon

[Marc]

"Nicholas Paldino [.NET/C# MVP]" <mv*@spam.guard .caspershouse.c omwrote

Or, he could just use a definition of GetPrivateProvi deSection which
would marshal the string correctly. A declaration that uses bytes in the
parameter doesn't do any good.

The declaration should be:

[DllImport("kern el32.dll", CharSet=CharSet .Auto)]
static extern uint GetPrivateProfi leString(

I am using GetPrivateProfi leSECTION not GetPrivateProfi leSTRING

But I guess the defintion should be:

[DllImport("kern el32.dll", CharSet=CharSet .Auto)]
static extern uint GetPrivateProfi leSection(
string lpAppName,
[In, Out] char[] lpReturnedStrin g,
uint nSize,
string lpFileName);

And this I am using in my program:

[DllImport("kern el32.dll", CharSet = CharSet.Auto)]
static extern uint GetPrivateProfi leSectionW(stri ng lpAppName, IntPtr
lpReturnedStrin g, uint nSize, string lpFileName);

public static bool GetPrivateProfi leSectionAsCS(s tring appName, string
fileName, out string section)
{

So there is a difference, but do not ask me now what is correct.

And there is also this little problem. The section is not one null
terminated string but several. This is in MSDN

"The format of the returned keys and values is one or more null-terminated
strings, followed by a final null character. Each string has the following
form: key=string"

I've already used GetPrivateProfi leSTRING, that one was easy. Ok, I will
look into it and thanks for suggestions.

[Nicholas Paldino [.NET/C# MVP]]

Marc,

Regardless, if you use the character array, then you can parse the
character array, looking for the null characters, and splitting the strings
apart that way.
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard. caspershouse.co m

"Marc" <in**@ingcarlea se.nlwrote in message
news:%2******** ********@TK2MSF TNGP02.phx.gbl. ..

>
"Nicholas Paldino [.NET/C# MVP]" <mv*@spam.guard .caspershouse.c omwrote

> Or, he could just use a definition of GetPrivateProvi deSection which
would marshal the string correctly. A declaration that uses bytes in the
parameter doesn't do any good.

The declaration should be:

[DllImport("kern el32.dll", CharSet=CharSet .Auto)]
static extern uint GetPrivateProfi leString(

I am using GetPrivateProfi leSECTION not GetPrivateProfi leSTRING

But I guess the defintion should be:

[DllImport("kern el32.dll", CharSet=CharSet .Auto)]
static extern uint GetPrivateProfi leSection(
string lpAppName,
[In, Out] char[] lpReturnedStrin g,
uint nSize,
string lpFileName);

And this I am using in my program:

[DllImport("kern el32.dll", CharSet = CharSet.Auto)]
static extern uint GetPrivateProfi leSectionW(stri ng lpAppName, IntPtr
lpReturnedStrin g, uint nSize, string lpFileName);

public static bool GetPrivateProfi leSectionAsCS(s tring appName, string
fileName, out string section)
{

So there is a difference, but do not ask me now what is correct.

And there is also this little problem. The section is not one null
terminated string but several. This is in MSDN

"The format of the returned keys and values is one or more null-terminated
strings, followed by a final null character. Each string has the following
form: key=string"

I've already used GetPrivateProfi leSTRING, that one was easy. Ok, I will
look into it and thanks for suggestions.

[Marc]

"Nicholas Paldino [.NET/C# MVP]" <mv*@spam.guard .caspershouse.c om>

Marc,

Regardless, if you use the character array, then you can parse the
character array, looking for the null characters, and splitting the
strings apart that way.

Hey thanks, this works:

[DllImport("kern el32.dll", CharSet = CharSet.Auto)]
static extern uint GetPrivateProfi leSection(strin g lpAppName, [In, Out]
char[] lpReturnedStrin g, uint nSize, string lpFileName);
//
public static bool GetPrivateProfi leSectionAsComm aText(string appName,
string fileName, out string section)
{
section = "";
uint MAX_BUFFER = 327670;
char[] sectionchar = new char[MAX_BUFFER];
if (!System.IO.Fil e.Exists(fileNa me))
return false;
uint bytesReturned = GetPrivateProfi leSection(appNa me, sectionchar,
MAX_BUFFER, fileName);
if ((bytesReturned == MAX_BUFFER - 2) || (bytesReturned == 0))
return false;
for (int i = 0; i < bytesReturned; i++)
{
if (sectionchar[i] != (char)0)
section += sectionchar[i];
else
{
if (i != bytesReturned - 1) section += ',';
}
}
return true;
}

>