如何修复Masm32：错误LNK2001：未解析的外部符号

我正在创建一个应用程序来测试api函数IsCharLowerA，然后使用MessageBoxA输出res。我正在使用masm32。

link /SUBSYSTEM:WINDOWS kod.obj
microsoft (R) Incremental Linker Version 5.12.8078
Copyright (C) microsoft Corp 1992-1998. All rights reserved.

kod.obj : warning LNK4033: converting object format from OMF to COFF
kod.obj : error LNK2001: unresolved external symbol __ExitProcess@4
kod.obj : error LNK2001: unresolved external symbol __MessageBoxA@16
kod.obj : error LNK2001: unresolved external symbol __imp__printf
kod.obj : error LNK2001: unresolved external symbol __imp__scanf
kod.obj : error LNK2001: unresolved external symbol _IsCharLowerA@4
LINK : error LNK2001: unresolved external symbol _WinmainCRTStartup

ml kod.asm
microsoft (R) Macro Assembler Version 6.14.8444
Copyright (C) microsoft Corp 1981-1997.  All rights reserved.

 Assembling: kod.asm
microsoft (R) Incremental Linker Version 5.12.8078
Copyright (C) microsoft Corp 1992-1998. All rights reserved.

/z2
"kod.obj"
"kod.exe"
NUL
LINK : warning LNK4044: unrecognized option "z2"; ignored
kod.obj : warning LNK4033: converting object format from OMF to COFF
LINK : fatal error LNK1181: cannot open input file "kod.exe"

我尝试使用microsoft masm32（在Visual Studio中编译代码），但是当应用程序启动时，仅要求输入一个字符然后关闭。由于出现“源不可用”错误，我无法尝试调试。

某些代码：

.586 
.model flat,stdcall 
option casemap: none 

include C:\masm32\include\windows.inc 
include C:\masm32\include\kernel32.inc 
include C:\masm32\include\user32.inc 
include C:\masm32\include\msvcrt.inc

includelib C:\masm32\lib\msvcrt.lib
includelib C:\masm32\lib\kernel32.lib
includelib C:\masm32\lib\user32.lib 

.data
msg db 'Enter char: ',0
messagebox_title db ' Лабораторна робота № 5 ',0
result_0 db ' NOT LOWERCASE ',0
result_1 db ' LOWERCASE ',0
scan_modifier db '%c',0    

.data?
scan_res dd ?

.code
start:  
    push ebp
    mov ebp,esp

    invoke crt_printf,OFFSET msg

    invoke crt_scanf,OFFSET scan_modifier,scan_res

    push scan_res
    call IsCharLowerA

    push 0
    push offset messagebox_title        

    cmp eax,0
    jne notNULL
    push offset result_0
    jmp next
notNULL:
    push offset result_1
next:
    push 0                           
    call MessageBoxA          

    push 0                        
    call ExitProcess   

    pop ebp
end start

更新＃1 ：（已更改MessageBoxA-> MessageBoxA @ 16等）

代码：

.586 
.model flat,stdcall 
option casemap: none 

include C:\masm32\include\windows.inc 
include C:\masm32\include\kernel32.inc 
include C:\masm32\include\user32.inc 
include C:\masm32\include\msvcrt.inc

includelib C:\masm32\lib\msvcrt.lib
includelib C:\masm32\lib\kernel32.lib
includelib C:\masm32\lib\user32.lib 

extrn MessageBoxA@16 : PROC
extrn ExitProcess@4 : PROC

.data
msg db 'Enter char: ',0
    jne notNULL
    push offset result_0
    jmp next
notNULL:
    push offset result_1
next:
    push 0                           
    call MessageBoxA@16          

    push 0                        
    call ExitProcess@4   

    pop ebp
end start

Res：

link /SUBSYSTEM:WINDOWS kod.obj
microsoft (R) Incremental Linker Version 5.12.8078
Copyright (C) microsoft Corp 1992-1998. All rights reserved.

kod.obj : warning LNK4033: converting object format from OMF to COFF
kod.obj : error LNK2001: unresolved external symbol _MessageBoxA@16
kod.obj : error LNK2001: unresolved external symbol __imp__printf
kod.obj : error LNK2001: unresolved external symbol _ExitProcess@4
kod.obj : error LNK2001: unresolved external symbol __imp__scanf
kod.obj : error LNK2001: unresolved external symbol _IsCharLowerA@4
LINK : error LNK2001: unresolved external symbol _WinmainCRTStartup
kod.exe : fatal error LNK1120: 6 unresolved externals

我有一个代码error LNK2001: unresolved external symbol _MessageBox（上传的＃2“最终工作代码”）也无法成功链接

问题是：

1）对于scanf需要OFFSET scan_res，因为不需要值。
2）不能同时使用Windows和控制台子系统进行编译。这就是为什么我只使用printfs的原因。
3）库msvcrt不够。
4）从OMF转换为COFF可以忽略。

工作代码：

.586 
.model flat,stdcall 
option casemap: none 

include C:\masm32\include\windows.inc 
include C:\masm32\include\user32.inc 
include C:\masm32\include\msvcrt.inc

includelib C:\masm32\lib\msvcrt.lib
includelib C:\masm32\lib\user32.lib 

.data
msg db 'Enter char: ',0
result_0 db ' NOT LOWERCASE ',0
result_1 db ' LOWERCASE ',0
scan_modifier db '%c',0    

.data?
scan_res dd ?

.code
start:  
    mov ebp,esp

    invoke crt_printf,OFFSET msg

    invoke crt_scanf,OFFSET scan_modifier,OFFSET scan_res

    push scan_res
    call IsCharLowerA    

    cmp eax,0
    jne notNULL
    invoke crt_printf,OFFSET result_0
    jmp next
notNULL:
    invoke crt_printf,OFFSET result_1
next:                                                         
    ret
end start

如何修复Masm32：错误LNK2001：未解析的外部符号

aniu8258 回答：如何修复Masm32：错误LNK2001：未解析的外部符号

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