关于vb.netthrow的信息( 二 )


//线程钩子监听鼠标消息设为7,全局钩子监听鼠标消息设为14 。
//
//lpfn 钩子子程的地址指针 。如果dwThreadId参数为0 或是一个由别的进程创建的线程的标识,lpfn必须指向DLL中的钩子子程 。除此以外 , lpfn可
//以指向当前进程的一段钩子子程代码 。钩子函数的入口地址,当钩子钩到任何消息后便调用这个函数 。
//
//hInstance应用程序实例的句柄 。标识包含lpfn所指的子程的DLL 。如果threadId 标识当前进程创建的一个线程,而且子程代码位于当前
//进程 , hInstance必须为NULL 。可以很简单的设定其为本应用程序的实例句柄 。
//
//threadedId 与安装的钩子子程相关联的线程的标识符 。如果为0 , 钩子子程与所有的线程关联,即为全局钩子 。
//************************************
// 如果设置钩子失败
if(hKeyboardHook == 0 )
{
HookStop();
throw new Exception("SetWindowsHookEx failed.");
}
}
}
// 卸载钩子
public void HookStop()
{
bool retKeyboard = true;
if(hKeyboardHook != 0)
{
retKeyboard = UnhookWindowsHookEx(hKeyboardHook);
hKeyboardHook = 0;
}
if (!( retKeyboard))
throw new Exception("UnhookWindowsHookEx failed.");
}
初学vb.net,打开数据库的时候,运行到connStr.Open()程序好像死掉了,这是怎么回事?connStr.ConnectionString = "Data Source=localhost;Initial Catalog=test1;user id=sa;password=123456"
一般是你这里的设置写的不对导致找不到数据服务器 导致一直处于连接中的状态,需要等待超时 才会有反应
vb.net 怎么知道按下了多个按键用APIGetKeyboardState  , 判断所有vb.netthrow的键里哪些被按下vb.netthrow了 。
下面的是判断键盘灯的状态
Public Class NativeMethods
Private Shared keyState() As Byte
DllImport("user32.dll") _
Private Shared Function GetKeyboardState(ByVal keyState() As Byte) As Boolean
End Function
Private Shared Sub Update()
keyState = New Byte(256) {}
Dim result As Boolean = GetKeyboardState(keyState)
' Check for error:
If result = False Then
Debug.WriteLine("GetKeyBoardState error: "Marshal.GetLastWin32Error)
Throw New Exception("GetKeyBoardState error: "Marshal.GetLastWin32Error)
End If
End Sub
Public Enum LightState
Off
[On]
End Enum
' Example - the keyboard lights...
Public Shared ReadOnly Property CapsLockState() As LightState
Get
Update()
Dim isOn As Boolean = (keyState(Keys.CapsLock) = 1)
Return IIf(isOn, LightState.On, LightState.Off)
End Get
End Property
Public Shared ReadOnly Property NumLockState() As LightState
Get
Update()
Dim isOn As Boolean = (keyState(Keys.NumLock) = 1)
Return IIf(isOn, LightState.On, LightState.Off)
End Get
End Property
Public Shared ReadOnly Property ScrollLockState() As LightState
Get
Update()
Dim isOn As Boolean = (keyState(Keys.Scroll) = 1)
Return IIf(isOn, LightState.On, LightState.Off)
End Get
End Property
End Class
vb.net中向数据库写入数据后如何更新??(急,在线等)Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Dim shkcode1 As String
Dim shimei1 As String
Dim inymd1 As String
Dim sqlstr As String
' Dim dr As DataRow
shkcode1 = DataGridView1.Rows(4).Cells(0).Value
shimei1 = DataGridView1.Rows(4).Cells(1).Value
inymd1 = DataGridView1.Rows(4).Cells(2).Value
sqlstr = " insert into EA_M1施设职员(shkcode,shimei,inymd) values ('"shkcode1"','"shimei1"','"inymd1"')"
Dim connection As New OracleConnection("连接字符串")

推荐阅读