即使窗口存在,FindWindow在MASM32程序中返回零

Question

我正在尝试用汇编编写程序,我需要的第一件事就是特定进程主窗口的句柄.我一直试图用FindWindow来获取它,但到目前为止没有运气; FindWindow显然保持零返回.任何人都可以指出我在这里缺少什么？谢谢.

.486
.model flat, stdcall
option casemap :none
include \masm32\include\user32.inc
include \masm32\include\kernel32.inc
includelib \masm32\lib\user32.lib
includelib \masm32\lib\kernel32.lib

.data
    NtpTitle    db  "Untitled - Notepad",0
    MsgNoNtp    db  "Notepad not found.",0
    MsgNtp      db  "Found Notepad.",0
    NullString  db  0
    hWndNtp     dd  0

.code
start:
    invoke FindWindow, offset NullString, offset NtpTitle
    mov hWndNtp, eax
    jz noNotepad
    invoke MessageBox, 0, offset MsgNtp, 0, 40h
    invoke ExitProcess, 0

noNotepad:
    invoke MessageBox, 0, offset MsgNoNtp, 0, 10h
    invoke ExitProcess, 1

end start

Answer 1

您应该设置lpClassName为NULL,而不是空字符串的地址.

invoke FindWindow, 0, offset NtpTitle

你没有测试的回报值FindWindow; mov不会修改标志.

test eax,eax
jz noNotepad