如何在结构x8086的数组中添加成员

Question

I'm still having trouble with structures in assembly and I'm stuck with adding members inside an array of structure. I'm able to add members now, but instead of just adding one in an array of structure, it overwrites all the members that I've added earlier. So all the members of the array will be similar to the last one that I added.

Here's the data initialization

menu db 10, '------MENU------', 10, '1. Add Student', 10, '2. Delete Student', 10, '3. Delete All', 10, '4. Search Student', 10, '5. Display All', 10, '6. Exit', 10 
menulen equ $-menu
fnamep db 'Enter firstname: '
fnameplen equ $-fnamep
lnamep db 'Enter lastname: '
lnameplen equ $-lnamep
agep db 'Enter age: '
ageplen equ $-agep
unitsp db 'Enter units enrolled: '
unitsplen equ $-unitsp
fullp db 'Sorry, the record is already full.', 10
fullplen equ $-fullp
record db '----Student Record----', 10
recordlen equ $-record
space db ' '
spacelen equ $-space
newline db '', 10
newlinelen equ $-newline
printfname db 'First name: '
printfnamelen equ $-printfname
printlname db 'Last name: '
printlnamelen equ $-printlname
printage db 'Age: '
printagelen equ $-printage
printunits db 'Number of units enrolled: '
printunitslen equ $-printunits
student equ 94
firstname equ 0
firstnamelen equ 40
lastname equ 42
lastnamelen equ 82
age equ 86
units equ 90
array_size equ 5

choice resb 1
x resb array_size*student
size resb 1
temp resb 1

Here's the adding to the structure part.

    cmp byte[size], 5
    jge full

    mov eax, 4
    mov ebx, 1
    mov ecx, fnamep
    mov edx, fnameplen
    int 80h

    mov eax, 3
    mov ebx, 0
    imul ecx,esi,size                  
    lea ecx,[ecx+esi+x+student+firstname]
    mov edx, 20
    int 80h

    mov eax, 4
    mov ebx, 1
    mov ecx, lnamep
    mov edx, lnameplen
    int 80h

    mov eax, 3
    mov ebx, 0
    imul ecx,esi,size                  
    lea ecx,[ecx+esi+x+student+lastname]
    mov edx, 20
    int 80h

    mov eax, 4
    mov ebx, 1
    mov ecx, agep
    mov edx, ageplen
    int 80h


    mov eax, 3
    mov ebx, 0
    imul ecx,esi,size                    
    lea ecx,[ecx+esi+x+student+age]
    mov edx, 3
    int 80h


    mov eax, 4
    mov ebx, 1
    mov ecx, unitsp
    mov edx, unitsplen
    int 80h


    mov eax, 3
    mov ebx, 0
    imul ecx,esi,size                   
    lea ecx,[ecx+esi+x+student+units]
    mov edx, 3
    int 80h


    add byte[size], 1
    jmp menustart

And here's the displaying all part

    mov eax, 4
    mov ebx, 1
    mov ecx, record
    mov edx, recordlen
    int 80h

    mov al, byte[size]
    mov [temp], al

    mov eax, 4
    mov ebx, 1
    mov ecx, newline
    mov edx, newlinelen
    int 80h
    displayloop:
        cmp byte[temp], 0
        je menustart

        mov eax, 4
        mov ebx, 1
        mov ecx, printfname
        mov edx, printfnamelen
        int 80h

        mov eax, 4
        mov ebx, 1
        imul ecx,esi,temp   
        lea ecx, [ecx+x+student+firstname]
        mov edx, 20
        int 80h

        mov eax, 4
        mov ebx, 1
        mov ecx, printlname
        mov edx, printlnamelen
        int 80h

        mov eax, 4
        mov ebx, 1
        imul ecx,esi,temp   
        lea ecx, [ecx+x+student+lastname]
        mov edx, 20
        int 80h

        mov eax, 4
        mov ebx, 1
        mov ecx, printage
        mov edx, printagelen
        int 80h


        mov eax, 4
        mov ebx, 1
        imul ecx,esi,temp    
        lea ecx, [ecx+x+student+age]
        mov edx, 3
        int 80h

        mov eax, 4
        mov ebx, 1
        mov ecx, printunits
        mov edx, printunitslen
        int 80h


        mov eax, 4
        mov ebx, 1
        imul ecx,esi,temp   
        lea ecx, [ecx+x+student+units]
        mov edx, 3
        int 80h

        mov eax, 4
        mov ebx, 1
        mov ecx, newline
        mov edx, newlinelen
        int 80h

        dec byte[temp]
        jmp displayloop

Answer 1

These instructions need to change in your code

imul ecx,esi,size
imul ecx,esi,temp  

You are multiplying with the address of these variables in stead of their values! Ideally you would use the following :

imul ecx,esi,[size]
imul ecx,esi,[temp]  

But these operands are not possible!!!
I suggest using a construct like :

mov ecx,esi
imul ecx,[size]

mov ecx,esi
imul ecx,[temp]

Also change the size of both variables to DWORD in stead of BYTE. IMUL requires it.