the c code:
char buffer[] = { 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16 };
char* data = buffer 4;
data = (data - buffer 3) / 4 * 4 buffer;
int result = data[0];
I convert it to vb.net
Dim buffer() As Byte = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}
Dim data() As Byte = buffer.Skip(4).ToArray()
Dim len = (buffer.Length - data.Length 3) \ 4 * 4
data = buffer.Skip(len).ToArray
Dim result As Integer = data(0)
Calculation results are inconsistent. in c result is 5, vb.net is 8.How can I convert it correctly?
CodePudding user response：
I'm not really sure what you are trying to achieve but, on the c code you are initializing a variable buffer as an array of CHAR, that means you'll convert 1 into char 1, 2 into char 2 etc... if you debug with a breakpoint you'll see that 1 will be converted into '\x1', 7 in '\a' for example... then you inizialize data as a pointer, and it points to the 5th element of buffer. Then you do something not really clear to me but it doesn't change the value of data. Then you retrieve the value of data as an int, and it's gonna be 5.
In vb.net you can't convert from char to integer and vice versa. So you can't really convert your c code.
Also, in the vb.net code, you inizialize buffer as an array of 16 elements, then you initialize data as an array of 12 elements, that starts from 5 (not a pointer this time). Then you inizialize len, which is gonna be 7, cause you have 16 - 12 3 = 7, and then you divide and multiply 7 by 4, which is gonna give you 7. Then you tell data to be again an array of bytes, but this time instead of skipping the first 4 elements of buffer, skip the first 7 (len) elements... Of course you'll get 8 as result.
If you can, please explain what you are trying to do here:
char* data = buffer 4;
data = (data - buffer 3) / 4 * 4 buffer;
Because it's not very clear to me and certain operations are not possible in vb.net
CodePudding user response：
This is the original code
void GetDialogEx(char *buf, CStrID id)
{ struct DialogBoxHeaderEx { DWORD SignEx; DWORD Version; DWORD ExStyle; DWORD Style; WORD DlgItems; WORD x; WORD y; WORD cx; WORD cy; WCHAR menuName[1]; } Header = (DialogBoxHeaderEx)buf;
if(Header->ExStyle) Print("EXSTYLE 0x%.8X\n", Header->ExStyle);
WCHAR *ClassName,*szCaption;
char *ItemData;
if(Header->menuName[0] == 0xFFFF)
{
Print("MENU %d\n",Header->menuName[1]);
ClassName = Header->menuName 2;
}
else if(Header->menuName[0])
{
Puts("MENU \"");
ClassName = (WCHAR*)WPuts(Header->menuName);
Puts("\"\n");
}
else ClassName = Header->menuName 1;
if(*ClassName == 0xFFFF)
{
Print("CLASS %d\n",ClassName[1]);
szCaption = ClassName 2;
}
else if(*ClassName)
{
Puts("CLASS \"");
szCaption = (WCHAR*)WPuts(ClassName);
Puts("\"\n");
}
else szCaption = ClassName 1;
if(*szCaption)
{
Puts("CAPTION \"");
ItemData = (char*)WPuts(szCaption);
Puts("\"\n");
}
else ItemData = (char*)(szCaption 1);
if(Header->Style & DS_SETFONT)
{
struct DialogFontEx
{
WORD wPointSize;
WORD Weight;
BYTE Italic;
BYTE CharSet;
WCHAR FontName[1];
} *Font = (DialogFontEx*)ItemData;
Print("FONT %d, \"", Font->wPointSize);
ItemData = (char*)WPuts(Font->FontName);
Print("\", %d, %d, %d\n", Font->Weight, Font->Italic, Font->CharSet);
}
Puts("BEGIN\n");
for(int i=0; i<Header->DlgItems; i )
{
ItemData = (ItemData - buf 3) /4*4 buf;
ItemData = GetDialogItem(ItemData, true);
}
Puts("END\n");
}
and my converted code:
#Region "ControlList"
Dim ctlData As Object
If isDialogEx Then
ctlData = New ControlDataEx()
Else
ctlData = New ControlData()
End If
Dim bItemData() As Byte = bFontData.Skip(2).ToArray()
'bItemData = (bItemData.Length - bytesIn.Length 3) / 4 * 4 bItemData
For i As Integer = 0 To DlgBoxHeader.DlgItems - 1
len = (bytesIn.Length - bItemData.Length 3) \ 4
bItemData = bytesIn.Skip(len * 4).ToArray
size = Marshal.SizeOf(ctlData)
buff = Marshal.AllocHGlobal(size)
Marshal.Copy(bItemData.Take(size).ToArray(), 0, buff, size)
If isDialogEx Then
ctlData = CType(Marshal.PtrToStructure(buff, GetType(ControlDataEx)), ControlDataEx)
Else
ctlData = CType(Marshal.PtrToStructure(buff, GetType(ControlData)), ControlData)
End If
Marshal.FreeHGlobal(buff)
'Debug.Print("Constol ID:" ctlData.id.ToString)
'Dim Style = If(isDialogEx, ctlData.Style, ctlData.ExStyle)
'Dim styleValue = Style And &HF
'Debug.Print("style:0x" CInt(ctlData.style).ToString("x8") " exstyle:0x" CInt(ctlData.exstyle).ToString("x8") " style value:" styleValue.ToString)
Dim bClassID() As Byte = bItemData.Skip(size 2).ToArray()
If bClassID(0) = &HFF And bClassID(1) = &HFF Then '控件类型
bClassID = bClassID.Skip(2).ToArray()
End If
If bClassID(0) = &H80 And bClassID(1) = 0 Then
Debug.Print("Button")
ElseIf bClassID(0) = &H81 And bClassID(1) = 0 Then
Debug.Print("EditText")
ElseIf bClassID(0) = &H82 And bClassID(1) = 0 Then
Debug.Print("Static")
ElseIf bClassID(0) = &H83 And bClassID(1) = 0 Then
Debug.Print("ListBox")
ElseIf bClassID(0) = &H84 And bClassID(1) = 0 Then
Debug.Print("ScrollBar")
ElseIf bClassID(0) = &H85 And bClassID(1) = 0 Then
Debug.Print("ComboBox")
ElseIf bClassID(0) <> 0 Then
len = GetUnicodeString(bClassID, outString)
Debug.Print(outString)
bClassID = bClassID.Skip(len).ToArray()
End If
bClassID = bClassID.Skip(2).ToArray()
If bClassID(0) = &HFF And bClassID(1) = &HFF Then
bClassID = bClassID.Skip(2).ToArray()
len = GetUnicodeString(bClassID, outString)
result.Add(text ctlData.id.ToString() ":" outString)
Debug.Print(text ctlData.id.ToString() ":" outString)
bClassID = bClassID.Skip(len).ToArray()
Else
len = GetUnicodeString(bClassID, outString)
result.Add(text ctlData.id.ToString() ":" outString)
Debug.Print(text ctlData.id.ToString() ":" outString)
bClassID = bClassID.Skip(len).ToArray()
End If
bClassID = bClassID.Skip(2).ToArray
Debug.Print(vbNewLine)
If isDialogEx Then bItemData = bClassID.Skip(2).ToArray
Next i
Catch ex As Exception
End Try
#End Region