VC如何调用汇编子程序？
编写两个汇编语言子程序，分别返回系统的当前日期和时间，编写一个C语言程序，调用这两个汇编语言子程序，显示系统的当前日期和时间。
程序运行时显示的信息格式为：
Current date is 10-30-2001. Current time is 10:23:26.12
我的实现如下，为什么不能编译，我已经在VC工程那link了obj文件：
#include <stdio.h>
#include <iostream.h>
extern "C " int get();
int main()
{
get();
return 0;
}
汇编子程序：（单独执行能够成功）
;========================================== ；get.asm
;A little assembly app that shows the current date and time.
;It can be done a lot easier, but this way you will
;see how to do some basic memory manipulation, and how to use 'variables '.
;==========================================
.model small
.stack
;===========================
;Data segment starts here
;===========================
.data
date_str DB "Current date is: yyyy-mm-dd ", 0Ah, 0Dh, "$ "
time_str DB "Current time is: hh.mm.ss:xx ", 0Ah, 0Dh, "$ "
min_size DW ?
padd_chr DB ?
;===========================
;Code segment starts here
;===========================
.code
PUBLIC _get
;main
_get PROC
MOV AX, SEG @data ;First we get the data segment address
MOV DS, AX ;and store it into ds
MOV [min_size], 02h ;Results should always be at least two digits
MOV [padd_chr], '0 ' ;Use '0 ' as padding-character
MOV AH, 2Ah ;Then we call int 21h,2Ah, which will give
INT 21h ;us the current date
LEA DI, date_str ;Then we load the address of the date_str string
ADD DI, 17 ;and set si to point at the first y in yyyy-...
MOV AX, CX ;Next we mov cx to ax and
CALL todec ;call todec
INC DI ;We skip the '- ' character...
XOR AX, AX ;Then we empty ax
MOV AL, DH ;And set the low-byte of ax to dh
CALL todec
INC DI ;Skip character in string...
XOR AX, AX ;Empty ax
MOV AL, DL ;Set low-byte to dl
CALL todec ;Convert it to base10
LEA DI, time_str ;Now we load the time_str string
ADD DI, 17 ;And set the correct pointer offset
MOV AH, 2Ch ;And then we call int 21h,2Ch
INT 21h ;which will give us the current time
XOR AX, AX ;Empty ax
MOV AL, CH ;Set low-byte to ch
CALL todec ;Convert it to base10
INC DI ;Skip character
MOV AL, CL ;Set low-byte to cl
CALL todec ;Convert to base10
INC DI ;Skip character
MOV AL, DH ;Set low-byte to dh
CALL todec ;Convert to base10
INC DI ;Skip character
MOV AL, DL ;Set low-byte to dl
CALL todec ;Convert to base10
MOV DX, OFFSET date_str ;Now load offset of the date_str string into dx
CALL print ;And print the (modified) string
MOV DX, OFFSET time_str ;Load offset of the time_str string into dx
CALL print ;And print the (modified) string
MOV AX, 4C00h ;Do a clean exit(error code=00)
INT 21h
;===================================================================
;todec - converts the contents of ax into base10 ascii character(s)
; of length bx
; min_size defines minimum length of result, and padd_char
; defines the padding character.
;The result(s) are stored at ds:di
;===================================================================
todec PROC
PUSH AX ;Save all registers
PUSH BX
PUSH CX
PUSH DX
XOR CX,CX ;Empty the POP counter
MOV BX,10 ;Base divisor
decloop:
XOR DX,DX ;Set the high 16-bits to 0
DIV BX ;Preform division(dx=remainder, ax=quotient)
INC CX ;Increase the counter
PUSH DX ;and save the remainder
CMP AX,0 ;If the quotient != 0
JNZ decloop ;then get one more number
MOV BX, [min_size] ;Load min_size value into bx
MOV DL, [padd_chr] ;Load padd_chr value into dl
padd_result:
CMP CX, BX ;Is cx > = min_size?
JGE poploop ;If so, proceed
MOV BYTE PTR DS:[DI], DL ;Else padd with padd_chr
INC DI ;and increase string pointer
DEC BX ;decrease bx
JMP padd_result ;and test for more padding
poploop:
POP DX ;Get the number of the stack
ADD DL, '0 ' ;and add '0 ' to it
MOV BYTE PTR DS:[DI], DL ;Modify the string at ds:di
INC DI ;Increase the string pointer
DEC CX ;Decrease the loop counter
JNZ poploop
POP DX ;Restore all registers
POP CX
POP BX
POP AX
RET ;And return from call
todec ENDP
;===========================================================
;print - prints the string pointed to by dx using int 21h,09
;===========================================================
print PROC
PUSH AX ;Save ax
PUSH DS ;and ds onto the stack
MOV AX, @data ;Then get the address of the data segment
MOV DS, AX ;and store it into ds
MOV AX, 0900h
INT 21h ;and then print the message pointed to by dx
POP DS ;Retrieve ds
POP AX ;and ax from stack
RET
print ENDP
_get ENDP
END
[解决办法]
0 v8086和win32是不同地
1 建议做成win32的dll形式。
[解决办法]
dll是一种方法.
另外一种办法是写成C的函数.
void get(){
__asm{
...
}
}
