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绝对值是“|”,可以直接显示,同理对数可用log(x)代替,根号和其他不支持显示。
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如果要显示数学式子,只能画吧。
计算时可用“^”求幂或求根,“/”表示除法和分数线,还有math类。
首先vb.net里大漠插件的findstr命令是不能用的,因为vb.net自身的问题。intx和inty值只会返回0,0. 我们要用findstrE这个命令 pos = findstr。。。。。。
然后用split function给出x和y值
第一个问题 qq聊天室 必须能 用vb都可以做
第二个问题 vb.net插入数学公式 可以把这些公式封装到一个类中,调用就是了
mports System.Drawing
Imports System.ComponentModel
Imports System.Windows.Forms
Imports System.Data.OleDb
Imports System.Data
Public Class Form1
Inherits Form
Private components As System.ComponentModel.Container = Nothing
Private WithEvents lastrec As Button
Private WithEvents nextrec As Button
Private WithEvents previousrec As Button
Private WithEvents firstrec As Button
Private t_books As TextBox
Private t_nl As TextBox
Private t_xb As TextBox
Private t_xm As TextBox
Private t_id As TextBox
Private l_books As Label
Private l_nl As Label
Private l_xb As Label
Private l_xm As Label
Private l_id As Label
Private label1 As Label
Private myDataSet As DataSet
Private WithEvents button1 As Button
Private WithEvents button2 As Button
Private WithEvents button3 As Button
Private WithEvents button4 As Button
Private myBind As BindingManagerBase
Public Sub New ( )
MyBase.New ( )
GetConnected ( )
InitializeComponent ( )
End Sub
'清除在程序中使用过的资源
Protected Overloads Overrides Sub Dispose (ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Dispose ( )
End If
End If
MyBase.Dispose ( disposing )
End Sub
Public Sub GetConnected ( )
'创建一个数据连接
Dim strCon As String = " Provider = Microsoft.Jet.OLEDB.4.0 ;
Data Source = db.mdb "
Dim myConn As OleDbConnection = New OleDbConnection ( )
myConn.ConnectionString = strCon
Dim strCom As String = " SELECT * FROM person "
'创建一个 DataSet
myDataSet = New DataSet ( )
myConn.Open ( )
'通过OleDbDataAdapter对象得到一个数据集
Dim myCommand As OleDbDataAdapter = New OleDbDataAdapter
( strCom , myConn )
'把Dataset绑定books数据表
myCommand.Fill ( myDataSet , "person" )
'关闭此数据连接
myConn.Close ( )
End Sub
'插入数据记录操作代码
Private Sub button2_Click (ByVal sender As Object , _
ByVal e As System.EventArgs) Handles button2.Click
'判断所有字段是否添完,添完则执行,反之弹出提示
If ( t_id.Text "" And t_xm.Text ""
And t_xb.Text "" And t_nl.Text ""
And t_books.Text "" ) Then
Dim myConn1 As String = " Provider = Microsoft.Jet.OLEDB.4.0 ;
Data Source = db.mdb"
Dim myConn As OleDbConnection = New OleDbConnection ( myConn1 )
myConn.Open ( )
Dim strInsert As String = " INSERT INTO person ( id , xm , xb , nl
, zip ) VALUES ( " _
t_id.Text + " , '" _
t_xm.Text + "' , '" _
t_xb.Text + "' , " _
t_nl.Text + " , " _
t_books.Text + ")"
Dim inst As OleDbCommand = New OleDbCommand ( strInsert , myConn )
inst.ExecuteNonQuery ( )
myConn.Close ( )
myDataSet.Tables ( "person" ).Rows ( myBind.Position ).BeginEdit ( )
myDataSet.Tables ( "person" ).Rows ( myBind.Position ).EndEdit ( )
myDataSet.Tables ( "person" ).AcceptChanges ( )
Else
MessageBox.Show ( "必须填满所有字段值!" , "错误!" )
End If
End Sub
你这个是操作多个窗口还是操作单个窗口
单个窗口的话,没必要创建多个对象,1个就够了。
如果特殊情况下需要创建多个大漠插件的对象,承载对象的变量可设置成数组型,或者可更换成模块去创建多个对象
我以前用过:如图,这个模块可以实现,需要的话精益论坛上有 搜索下
代码的写法如下:
1、先创建个全局变量的对象数组
2、如下
-1.52341E-13
科学计数法,10的-13次方表示此数已经接近于0了,应该是single类型的精度导致的,你把精度设置适当应该就可以了。