vb.net 如何写代码让SQL SERVER数据库自动计算

只要是提到“System.Data.OracleClient的”

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连接字符串的例子：

用户ID =用户;数据源=服务器/数据库名;密码=通过; - 其他与sqlserver的是相似的，但这种改变的OracleConnection

的SqlDataAdapter的SqlConnection想改变OracleDataAdapter

的SqlCommand想改变的OracleCommand

用VB.NET编的计算器程序！

Public Class SimpleCalculator

Inherits System.Windows.Forms.Form

#Region " Windows 窗体设计器生成的代码 "

Public Sub New()

MyBase.New()

'该调用是 Windows 窗体设计器所必需的。

InitializeComponent()

'在 InitializeComponent() 调用之后添加任何初始化

End Sub

'窗体重写处置以清理组件列表。

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

'Windows 窗体设计器所必需的

Private components As System.ComponentModel.IContainer

'注意：以下过程是 Windows 窗体设计器所必需的

'可以使用 Windows 窗体设计器修改此过程。

'不要使用代码编辑器修改它。

Friend WithEvents Label1 As System.Windows.Forms.Label

Friend WithEvents TextBox1 As System.Windows.Forms.TextBox

Friend WithEvents Button1 As System.Windows.Forms.Button

Friend WithEvents Button2 As System.Windows.Forms.Button

Friend WithEvents Button3 As System.Windows.Forms.Button

Friend WithEvents Button4 As System.Windows.Forms.Button

Friend WithEvents Button5 As System.Windows.Forms.Button

Friend WithEvents Button6 As System.Windows.Forms.Button

Friend WithEvents Button7 As System.Windows.Forms.Button

Friend WithEvents Button8 As System.Windows.Forms.Button

Friend WithEvents Button9 As System.Windows.Forms.Button

Friend WithEvents Button10 As System.Windows.Forms.Button

Friend WithEvents Button11 As System.Windows.Forms.Button

Friend WithEvents Button12 As System.Windows.Forms.Button

Friend WithEvents Button13 As System.Windows.Forms.Button

Friend WithEvents Button14 As System.Windows.Forms.Button

Friend WithEvents Button15 As System.Windows.Forms.Button

Friend WithEvents Button16 As System.Windows.Forms.Button

System.Diagnostics.DebuggerStepThrough() Private Sub InitializeComponent()

Me.Label1 = New System.Windows.Forms.Label

Me.TextBox1 = New System.Windows.Forms.TextBox

Me.Button1 = New System.Windows.Forms.Button

Me.Button2 = New System.Windows.Forms.Button

Me.Button3 = New System.Windows.Forms.Button

Me.Button4 = New System.Windows.Forms.Button

Me.Button5 = New System.Windows.Forms.Button

Me.Button6 = New System.Windows.Forms.Button

Me.Button7 = New System.Windows.Forms.Button

Me.Button8 = New System.Windows.Forms.Button

Me.Button9 = New System.Windows.Forms.Button

Me.Button10 = New System.Windows.Forms.Button

Me.Button11 = New System.Windows.Forms.Button

Me.Button12 = New System.Windows.Forms.Button

Me.Button13 = New System.Windows.Forms.Button

Me.Button14 = New System.Windows.Forms.Button

Me.Button15 = New System.Windows.Forms.Button

Me.Button16 = New System.Windows.Forms.Button

Me.SuspendLayout()

'

'Label1

'

Me.Label1.Location = New System.Drawing.Point(16, 16)

Me.Label1.Name = "Label1"

Me.Label1.Size = New System.Drawing.Size(48, 16)

Me.Label1.TabIndex = 0

Me.Label1.Text = "结果："

'

'TextBox1

'

Me.TextBox1.Location = New System.Drawing.Point(64, 8)

Me.TextBox1.Name = "TextBox1"

Me.TextBox1.Size = New System.Drawing.Size(120, 21)

Me.TextBox1.TabIndex = 1

Me.TextBox1.Text = ""

'

'Button1

'

Me.Button1.Location = New System.Drawing.Point(200, 8)

Me.Button1.Name = "Button1"

Me.Button1.Size = New System.Drawing.Size(56, 24)

Me.Button1.TabIndex = 2

Me.Button1.Text = "清空"

'

'Button2

'

Me.Button2.Location = New System.Drawing.Point(48, 56)

Me.Button2.Name = "Button2"

Me.Button2.Size = New System.Drawing.Size(24, 24)

Me.Button2.TabIndex = 3

Me.Button2.Text = "1"

'

'Button3

'

Me.Button3.Location = New System.Drawing.Point(88, 56)

Me.Button3.Name = "Button3"

Me.Button3.Size = New System.Drawing.Size(24, 24)

Me.Button3.TabIndex = 4

Me.Button3.Text = "2"

'

'Button4

'

Me.Button4.Location = New System.Drawing.Point(136, 56)

Me.Button4.Name = "Button4"

Me.Button4.Size = New System.Drawing.Size(24, 24)

Me.Button4.TabIndex = 5

Me.Button4.Text = "3"

'

'Button5

'

Me.Button5.Location = New System.Drawing.Point(48, 88)

Me.Button5.Name = "Button5"

Me.Button5.Size = New System.Drawing.Size(24, 24)

Me.Button5.TabIndex = 6

Me.Button5.Text = "4"

'

'Button6

'

Me.Button6.Location = New System.Drawing.Point(88, 88)

Me.Button6.Name = "Button6"

Me.Button6.Size = New System.Drawing.Size(24, 24)

Me.Button6.TabIndex = 7

Me.Button6.Text = "5"

'

'Button7

'

Me.Button7.Location = New System.Drawing.Point(136, 88)

Me.Button7.Name = "Button7"

Me.Button7.Size = New System.Drawing.Size(24, 24)

Me.Button7.TabIndex = 8

Me.Button7.Text = "6"

'

'Button8

'

Me.Button8.Location = New System.Drawing.Point(48, 120)

Me.Button8.Name = "Button8"

Me.Button8.Size = New System.Drawing.Size(24, 24)

Me.Button8.TabIndex = 9

Me.Button8.Text = "7"

'

'Button9

'

Me.Button9.Location = New System.Drawing.Point(88, 120)

Me.Button9.Name = "Button9"

Me.Button9.Size = New System.Drawing.Size(24, 24)

Me.Button9.TabIndex = 10

Me.Button9.Text = "8"

'

'Button10

'

Me.Button10.Location = New System.Drawing.Point(136, 120)

Me.Button10.Name = "Button10"

Me.Button10.Size = New System.Drawing.Size(24, 24)

Me.Button10.TabIndex = 11

Me.Button10.Text = "9"

'

'Button11

'

Me.Button11.Location = New System.Drawing.Point(48, 152)

Me.Button11.Name = "Button11"

Me.Button11.Size = New System.Drawing.Size(24, 24)

Me.Button11.TabIndex = 12

Me.Button11.Text = "0"

'

'Button12

'

Me.Button12.Location = New System.Drawing.Point(176, 56)

Me.Button12.Name = "Button12"

Me.Button12.Size = New System.Drawing.Size(24, 24)

Me.Button12.TabIndex = 13

Me.Button12.Text = "+"

'

'Button13

'

Me.Button13.Location = New System.Drawing.Point(176, 88)

Me.Button13.Name = "Button13"

Me.Button13.Size = New System.Drawing.Size(24, 24)

Me.Button13.TabIndex = 14

Me.Button13.Text = "-"

'

'Button14

'

Me.Button14.Location = New System.Drawing.Point(176, 120)

Me.Button14.Name = "Button14"

Me.Button14.Size = New System.Drawing.Size(24, 24)

Me.Button14.TabIndex = 15

Me.Button14.Text = "*"

'

'Button15

'

Me.Button15.Location = New System.Drawing.Point(176, 152)

Me.Button15.Name = "Button15"

Me.Button15.Size = New System.Drawing.Size(24, 24)

Me.Button15.TabIndex = 16

Me.Button15.Text = "/"

'

'Button16

'

Me.Button16.Location = New System.Drawing.Point(88, 152)

Me.Button16.Name = "Button16"

Me.Button16.Size = New System.Drawing.Size(72, 24)

Me.Button16.TabIndex = 17

Me.Button16.Text = "计算"

'

'SimpleCalculator

'

Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)

Me.ClientSize = New System.Drawing.Size(264, 190)

Me.Controls.Add(Me.Button16)

Me.Controls.Add(Me.Button15)

Me.Controls.Add(Me.Button14)

Me.Controls.Add(Me.Button13)

Me.Controls.Add(Me.Button12)

Me.Controls.Add(Me.Button11)

Me.Controls.Add(Me.Button10)

Me.Controls.Add(Me.Button9)

Me.Controls.Add(Me.Button8)

Me.Controls.Add(Me.Button7)

Me.Controls.Add(Me.Button6)

Me.Controls.Add(Me.Button5)

Me.Controls.Add(Me.Button4)

Me.Controls.Add(Me.Button3)

Me.Controls.Add(Me.Button2)

Me.Controls.Add(Me.Button1)

Me.Controls.Add(Me.TextBox1)

Me.Controls.Add(Me.Label1)

Me.Name = "SimpleCalculator"

Me.Text = "简单计算器"

Me.ResumeLayout(False)

End Sub

#End Region

Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)

End Sub

Private Sub TextBox1_TabStopChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)

End Sub

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

Dim btn As Button '按钮类型的变量

btn = sender '把产生该事件的按钮对象赋值给btn

TextBox1.Text = TextBox1.Text + btn.Text '把该按钮的Text属性值连接到TextBox1中

End Sub

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click

Dim btn As Button

btn = sender

TextBox1.Text += btn.Text

End Sub

Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click

Dim btn As Button

btn = sender

TextBox1.Text += btn.Text

End Sub

Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click

Dim btn As Button

btn = sender

TextBox1.Text += btn.Text

End Sub

Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button6.Click

Dim btn As Button

btn = sender

TextBox1.Text += btn.Text

End Sub

Private Sub Button7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button7.Click

Dim btn As Button

btn = sender

TextBox1.Text += btn.Text

End Sub

Private Sub Button8_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button8.Click

Dim btn As Button

btn = sender

TextBox1.Text += btn.Text

End Sub

Private Sub Button9_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button9.Click

Dim btn As Button

btn = sender

TextBox1.Text += btn.Text

End Sub

Private Sub Button10_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button10.Click

Dim btn As Button

btn = sender

TextBox1.Text += btn.Text

End Sub

Private Sub Button11_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button11.Click

Dim btn As Button

btn = sender

TextBox1.Text += btn.Text

End Sub

Private Sub Button12_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button12.Click

Dim btn As Button

btn = sender

'在文本框的Text属性后连接一个空格、本按钮的Text属性值和一个空格

TextBox1.Text = TextBox1.Text + " " + btn.Text + " "

End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

TextBox1.Text = "" '清空文本框

End Sub

Private Sub Button13_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button13.Click

Dim btn As Button

btn = sender

TextBox1.Text = TextBox1.Text + " " + btn.Text + " "

End Sub

Private Sub Button14_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button14.Click

Dim btn As Button

btn = sender

TextBox1.Text = TextBox1.Text + " " + btn.Text + " "

End Sub

Private Sub Button15_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button15.Click

Dim btn As Button

btn = sender

TextBox1.Text = TextBox1.Text + " " + btn.Text + " "

End Sub

Private Sub Button16_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button16.Click

'发生错误转移到标号“ErrorPro”指定的行去执行错误处理程序

On Error GoTo ErrorPro

Dim r As Decimal '保存计算结果的变量

Dim t As String = TextBox1.Text '用于保存文本框中的算术表达式

Dim space As Integer = t.IndexOf(" ") '搜索空格位置,如果没有空格，返回值为0

'字符串的取子符方法，第二个参数小于0，则将产生错误号为5的异常，即过程参数不正确

Dim s1 As String = t.Substring(0, space) '通过取子串方法获得第一个运算数

Dim op As String = t.Substring(space + 1, 1) '通过取子串方法获得运算符

Dim s2 As String = t.Substring(space + 3) '通过取子串方法获得第二个运算数

Dim arg1, arg2 As Integer

arg1 = Val(s1) : arg2 = Val(s2)

Select Case op

Case "+" : r = arg1 + arg2

Case "-" : r = arg1 - arg2

Case "*" : r = arg1 * arg2

Case "/" : r = arg1 / arg2

Case Else

MsgBox("输入的运算符有误！")

Exit Sub

End Select

TextBox1.Text = CStr(r) '显示结果

Exit Sub '退出过程

ErrorPro: '错误处理程序块

Select Case Err.Number

Case 6 '除数为零时，或运算溢出时的错误号

MsgBox("算术运算溢出！", , "溢出提示")

TextBox1.Focus()

Exit Sub

Case 5 ' Substring过程的参数不符合要求的错误号

MsgBox("必须输入运算符和第二个运算数！", , "运算数少")

Exit Sub

Case Else

'其它情况显示错误号和错误原因

MsgBox("错误号为" Err.Number Chr(10) Chr(13) "错误原因：" Err.Description)

Exit Sub

End Select

End Sub

End Class

我在用VB.net做一个计算程序，遇到一个问题。一个数15563，需要取出万位和千位（1500）

dim a as integer

a=15563

万位=a\10000

千位=a\1000 mod 10

百位=a\100 mod 10

if a mod 105 then 百位+=1

vb.net中如何解决公式计算的精确度问题

仅仅是普通表达式的话，定义数据类型，比如从单精度改为双精度，如果想保留小数点位数，用formatnumber来处理。如果是某个算法的精度，就要复杂一些，要定义一个误差，在算法迭代过程中，用while语句判断计算结果的残差是否小于定义的误差值，至于残差如何计算，与你的算法有关

vb.net 用循环计算数组中各元素之和

软糖来回答吧，VB.net用循环是这样的

Dim k = New Integer(9) {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

Dim 和 As Integer

For i = 0 To k.Count - 1

和 += k(i)

Next

计算数组中各元素之和更简单的方法是

使用扩展方法Sum或者Lambda表达式，以下两种均可

Dim 和1 = k.Sum()

Dim 和2 = k.Aggregate(Function(m, n) m + n)

vb.net 1.1中如何提高循环计算速度

运用多线程技术把一个任务分配到几个线程上让它们同时处理,这样会比单线程快很多,不过多线程技术不是一两话能说清的,你可以查一下相关的资料.

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