转：API在VB中应用之技巧集锦（ExcelHome 鱼之乐）-->tmtony转移

zhuyiwen

API函数在VB中得到了充分的运用，同时也让无数VB爱好者沉溺于其中。以下是笔者几年来收集整理的几十个API函数在VB中应用的实例，现在写出来与大伙分享，希望能对大伙有所帮助。


1、如何让窗体总在最前面？

' API函数声明

Declare Function SetWindowPos Lib "user32" ( ByVal hwnd As Long, ByVal hWndInsertAfter As Long, ByVal x As Long, ByVal y As Long, ByVal cx As Long, ByVal cy As Long, ByVal wFlags As Long) As Long

' 常量声明

Private Const SWP_NOSIZE = &H1
Private Const SWP_NOMOVE = &H2
Private Const HWND_TOPMOST = -1
Private Const HWND_NOTOPMOST = -2

' 在某个form里写：

SetWindowPos me.hWnd,WND_TOPMOST,0,0,0,0, SWP_NOMOVE    ' 或下面
SetWindowPos me.hWnd,WND_TOPMOST,0,0,0,0, SWP_NOSIZE

2、使用API函数sendmessage，获得光标所在行和列。

Sub getcaretpos(byval TextHwnd&,LineNo&,ColNo&)
　  ' TextHwnd为TextBox的hWnd属性值
    ' LineNo为所在行数
    ' ColNo为列数
　　dim i&,j&,k&                              ' 获取起始位置到光标所在位置字节数
    i=SendMessage(TextHwnd,&HB0&,0,0)
    j=i/2^16                                  ' 确定所在行
    LineNo=SendMessage(TextHwnd,&HC9&,j,0)+1  ' 确定所在列
　　k=SendMessage(TextHwnd,&HBB&,-1,0)
　　ColNo=j-k+1
End sub

3、如何以某种颜色填充某区域？

' API函数声明

Private Declare Sub FloodFill Lib "gdi32" _ (ByVal hDC As Long, ByVal X As Long, ByVal Y As _ Long, ByVal crColor As Long

' 设(fillx,filly)为此区域内任一点
' Color为某种颜色
FloodFill Picture1.hDC, fillx, filly,Color

4、如何关闭计算机？

' API函数声明

Declare Function ExitWindows Lib "User" (ByVal dwReturnCode As Long, ByVal wReserved As Integer) As Integer

' 执行

Dim DUMMY
DUMMY=ExitWindows(0，0)

5、如何获取Windows目录和System目录？

' 复制以下代码到一模块中

Public Declare Function GetWindowsDirectory Lib "kernel32" Alias "GetWindowsDirectoryA" (ByVal lpBuffer As String, ByVal nSize As Long) As Long
Public Declare Function GetSystemDirectory Lib "kernel32" Alias "GetSystemDirectoryA" (ByVal lpBuffer As String, ByVal nSize As Long) As Long

' 在程序中调用

   Dim WindowsDirectory As String, SystemDirectory As String, x As Long

   WindowsDirectory = Space(255)
   SystemDirectory = Space(255)
   x = GetWindowsDirectory(WindowsDirectory, 255)
   x = GetSystemDirectory(SystemDirectory, 255)
   MsgBox "Windows的安装目录是:" + WindowsDirectory+",系统目录是:" + SystemDirectory

6、如何建立简单的超级连接？

' API函数声明

Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecute A" (ByVal hWnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd A s Long) As Long

' 打开某个网址

ShellExecute 0, "open", "http://tyvb.126.com", vbNullString, vbNullString, 3

' 给某个信箱发电子邮件

ShellExecute hwnd, "open", "mailto:sst95@21cn.com", vbNullString, vbNullString, 0

7、如何得知TextBox中文字所有的行数？

' API函数声明

Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Public Const EM_GETLINECOUNT = &HBA

' 在程序中调用

LineCnt = SendMessage(ctl.hwnd, EM_GETLINECOUNT, 0, 0)
' LineCnt即为此TextBox的行数。

8、如何设置ListBox的水平卷动轴的宽度？

' API函数声明

Const LB_SETHORIZONTALEXTENT = &H194
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

' 调用

Call SendMessage(List1.hwnd, LB_SETHORIZONTALEXTENT, 400, ByVal 0&)
' 注意400是以象素为单位，你可以根据情况自行设定。

9、如何交换鼠标按键？

' API函数声明

Declare Function SwapMouseButton& Lib "user32" _ (ByVal bSwap as long)

' 要交换鼠标按键，将bSwap参数设置为True。要恢复正常设置，将bSwap设置为False。 然后调用函数就可以交换和恢复鼠标按键了。

10、如何让窗体的标题条闪烁以引起用户注意？

' 在窗体中放一个Timer控件Timer1,设置其Inteval=200
' API函数声明

Private Declare Function FlashWindow Lib "user32" (ByVal hwnd As Long, ByVal bInvert As Long) As Long

ganrong

好文章,绝对好文章,不知在ACCESS下试过能否?

tmtony

非常不错，大多是比较实用的例子，我把它放到精品推荐里去

xir

很好的参考资料，谢谢！

lieyan

如何与串口通讯？

木头人的木

学习了