Write text to Win32 Resources - vb.net

Question

I am trying to write text to Win32 resources, but I have failed with it.
Here it is after writing the text:
And here is how it should look like:
Here's my code:
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
WriteResourceStr(Target.Text, "hello")
End Sub
#Region "Second"
<DllImport("kernel32.dll", SetLastError:=True, CharSet:=CharSet.Unicode)> _
Private Shared Function UpdateResource(ByVal hUpdate As IntPtr, ByVal lpType As String, ByVal lpName As String, ByVal wLanguage As UShort, ByVal lpData As IntPtr, ByVal cbData As UInteger) As Boolean
End Function
<DllImport("kernel32.dll", SetLastError:=True, CharSet:=CharSet.Unicode)> _
Private Shared Function BeginUpdateResource(ByVal pFileName As String, <MarshalAs(UnmanagedType.Bool)> ByVal bDeleteExistingResources As Boolean) As IntPtr
End Function
<DllImport("kernel32.dll", SetLastError:=True, CharSet:=CharSet.Unicode)> _
Private Shared Function EndUpdateResource(ByVal hUpdate As IntPtr, ByVal fDiscard As Boolean) As Boolean
End Function
Public Function WriteResourceStr(ByVal filename As String, ByVal bytes As String) As Boolean
Try
Dim handle As IntPtr = BeginUpdateResource(filename, False)
Dim file1 As String = bytes
Dim fileptr As IntPtr = ToPtr(file1)
Dim res As Boolean = UpdateResource(handle, "RCData", "CONFIG", 1, fileptr, System.Convert.ToUInt16(file1.Length))
EndUpdateResource(handle, False)
Catch ex As Exception
Return False
End Try
Return True
End Function
Private Function ToPtr(ByVal data As Object) As IntPtr
Dim h As GCHandle = GCHandle.Alloc(data, GCHandleType.Pinned)
Dim ptr As IntPtr
Try
ptr = h.AddrOfPinnedObject()
Finally
h.Free()
End Try
Return ptr
End Function
#End Region
So seems like it doesn't write ANSI, but in Unicode. How to change that?
Hopefully somebody replies.

Answer 1

The simplest way to get this is to just overload UpdateResource and let Windows make the Unicode to ANSI conversion for you:
<DllImport("kernel32.dll", SetLastError:=True, CharSet:=CharSet.Ansi)> _
Private Shared Function UpdateResource(ByVal hUpdate As IntPtr, _
ByVal lpType As String, ByVal lpName As String, ByVal wLanguage As UShort,
ByVal lpData As String, ByVal cbData As Integer) As Boolean
End Function
Note the changed lpData type and the changed CharSet. The call now simply becomes:
Dim handle As IntPtr = BeginUpdateResource(filename, False)
If handle = IntPtr.Zero Then Throw New Win32Exception
Dim res As Boolean = UpdateResource(handle, "RCData", "CONFIG", 1, _
bytes, bytes.Length)
If Not EndUpdateResource(handle, False) Then Throw New Win32Exception
I'll have to restate the nonsensical nature of the call. RCData is a numbered resource type and not a string. Using a language ID of 1 makes little sense, that's Arabic so you wouldn't expect a Latin string in the resource. Whatever app reads this resource is unlikely to find it back.
Doing this correctly would require an overload that declares lpType as IntPtr so you can pass CType(10, IntPtr) for the RT_RCData resource type. The ToPtr() function is extremely evil, it returns a dangling pointer that will cause random data corruption. Just let the pinvoke marshaller generate the pointer by declaring the lpData argument as Byte(). You'd then use Encoding.GetBytes() to use the proper ANSI conversion. Thus:
<DllImport("kernel32.dll", SetLastError:=True, CharSet:=CharSet.Unicode)> _
Private Shared Function UpdateResource(ByVal hUpdate As IntPtr, _
ByVal lpType As IntPtr, ByVal lpName As String, ByVal wLanguage As UShort,
ByVal lpData As Byte(), ByVal cbData As Integer) As Boolean
End Function
With an additional overload required if lpName is a numbered instead of a named resource, use IntPtr.