Cbsize as long '
时间: 2023-11-12 07:05:34 浏览: 28
"CbSize as Long" 是一种定义 Win32 API 结构体的语句。在 Win32 API 中,许多结构体都包含一个名为 "cbSize" 的字段,用于指定结构体本身的大小。这个字段通常是一个整数类型,如 Long、DWORD 等。
在使用 Win32 API 函数时,需要将结构体的大小传递给函数,以便函数能够正确地识别和处理结构体。通常会在定义结构体时添加一个 "cbSize" 字段,并将其赋值为结构体的大小。例如:
```
Private Type MYSTRUCT
cbSize As Long
dwValue As Long
szString As String * 256
End Type
Private Sub Example()
Dim myStruct As MYSTRUCT
myStruct.cbSize = Len(myStruct)
myStruct.dwValue = 123
myStruct.szString = "Hello, world!"
' call some Win32 API function with myStruct
End Sub
```
这里定义了一个名为 "MYSTRUCT" 的结构体,它包含了一个 Long 类型的 "cbSize" 字段,一个 Long 类型的 "dwValue" 字段和一个长度为 256 的字符串。在使用结构体时,需要将 "cbSize" 字段赋值为结构体的大小,以便 Win32 API 函数能够正确地处理它。
相关问题
vb6.0实现系统托盘 源代码
在VB6.0中,要实现系统托盘的功能,可以使用Shell_NotifyIcon API来操作系统托盘。以下是一个基本的示例代码:
首先,在窗体的General Declarations部分添加如下代码:
Private Const NIM_ADD As Long = &H0
Private Const NIM_DELETE As Long = &H2
Private Const NIF_MESSAGE As Long = &H1
Private Const NIF_ICON As Long = &H2
Private Const NIF_TIP As Long = &H4
Private Const WM_MOUSEMOVE As Long = &H200
Private Const WM_LBUTTONUP As Long = &H202
Private Type NOTIFYICONDATA
cbSize As Long
hwnd As Long
uID As Long
uFlags As Long
uCallbackMessage As Long
hIcon As Long
szTip As String * 64
End Type
Private Declare Function Shell_NotifyIcon Lib "shell32.dll" Alias "Shell_NotifyIconA" (ByVal dwMessage As Long, pnid As NOTIFYICONDATA) As Boolean
Private Declare Function LoadIcon Lib "user32" Alias "LoadIconA" (ByVal hInstance As Long, ByVal lpIconName As Long) As Long
接下来,在窗体的Load事件中添加如下代码:
Private Sub Form_Load()
Dim nid As NOTIFYICONDATA
nid.cbSize = Len(nid)
nid.hwnd = Me.hwnd
nid.uID = vbNull
nid.uFlags = NIF_ICON Or NIF_TIP Or NIF_MESSAGE
nid.uCallbackMessage = WM_MOUSEMOVE
nid.hIcon = LoadIcon(0, ByVal IDI_APPLICATION)
nid.szTip = "系统托盘"
Shell_NotifyIcon NIM_ADD, nid
End Sub
然后,在窗体的QueryUnload事件中添加如下代码,实现点击关闭按钮时隐藏窗体到系统托盘:
Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
If UnloadMode = vbFormControlMenu Then
Cancel = 1
Me.Hide
End If
End Sub
最后,在窗体的MouseDown事件中添加如下代码,实现双击系统托盘图标显示窗体:
Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
If Button = vbLeftButton Then
Me.Show
Me.WindowState = vbNormal
End If
End Sub
通过以上代码,我们就可以实现在VB6.0中添加系统托盘的功能了。当程序运行时,窗体会自动隐藏到系统托盘图标中,双击图标即可显示窗体。
vb6.0多行文本的滚动条背景颜色怎么改变
在VB6.0中,多行文本的滚动条背景颜色可以使用API函数来改变。可以使用SendMessage函数发送消息给多行文本控件,以改变滚动条的背景颜色。
以下是示例代码:
```vb
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Private Const EM_GETSCROLLBAR = &HB4
Private Const SB_CTL = &H2
Private Const SIF_ALL = &H17
Private Type SCROLLINFO
cbSize As Long
fMask As Long
nMin As Long
nMax As Long
nPage As Long
nPos As Long
nTrackPos As Long
End Type
Private Sub ChangeScrollBarBackColor(txtBox As TextBox)
Dim scrollInfo As SCROLLINFO
scrollInfo.cbSize = Len(scrollInfo)
scrollInfo.fMask = SIF_ALL
'获取垂直滚动条句柄
Dim vScrollBarHwnd As Long
vScrollBarHwnd = SendMessage(txtBox.hWnd, EM_GETSCROLLBAR, SB_CTL, ByVal 0&)
'获取水平滚动条句柄
Dim hScrollBarHwnd As Long
hScrollBarHwnd = SendMessage(txtBox.hWnd, EM_GETSCROLLBAR, SB_CTL + 1, ByVal 0&)
'设置垂直滚动条背景颜色
SetScrollInfo vScrollBarHwnd, SIF_ALL, scrollInfo, True
SendMessage vScrollBarHwnd, &HB, 0, ByVal GetSysColor(COLOR_BTNFACE)
'设置水平滚动条背景颜色
SetScrollInfo hScrollBarHwnd, SIF_ALL, scrollInfo, True
SendMessage hScrollBarHwnd, &HB, 0, ByVal GetSysColor(COLOR_BTNFACE)
End Sub
Private Sub Form_Load()
ChangeScrollBarBackColor Text1
End Sub
```
在上面的代码中,我们定义了一个名为`ChangeScrollBarBackColor`的子过程,它接受一个多行文本控件作为参数。该子过程使用API函数获取垂直和水平滚动条的句柄,并使用SendMessage函数将背景颜色设置为系统按钮的背景颜色。
在Form_Load事件中,我们调用`ChangeScrollBarBackColor`子过程,并将多行文本控件`Text1`作为参数传递给它。
注意:使用API函数可能会导致不兼容的问题。因此,建议在使用之前备份您的代码。
相关推荐
![rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![doc](https://img-home.csdnimg.cn/images/20210720083327.png)
![rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![exe](https://img-home.csdnimg.cn/images/20210720083343.png)
![text/plain](https://img-home.csdnimg.cn/images/20210720083646.png)
![text/plain](https://img-home.csdnimg.cn/images/20210720083646.png)
![pdf](https://img-home.csdnimg.cn/images/20210720083512.png)
![pdf](https://img-home.csdnimg.cn/images/20210720083512.png)
![egg](https://img-home.csdnimg.cn/images/20210720083646.png)
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)