急急急??！十萬火急！！求VB.NET高手?。。?/h2>

描述不夠清楚，也沒有圖。你的界面是什么界面，是窗體還是其他的什么。

創(chuàng)新互聯(lián)公司專注于企業(yè)營銷型網(wǎng)站建設(shè)、網(wǎng)站重做改版、應(yīng)縣網(wǎng)站定制設(shè)計、自適應(yīng)品牌網(wǎng)站建設(shè)、H5場景定制、商城建設(shè)、集團(tuán)公司官網(wǎng)建設(shè)、外貿(mào)營銷網(wǎng)站建設(shè)、高端網(wǎng)站制作、響應(yīng)式網(wǎng)頁設(shè)計等建站業(yè)務(wù)，價格優(yōu)惠性價比高，為應(yīng)縣等各大城市提供網(wǎng)站開發(fā)制作服務(wù)。

如果是窗體，他會讓你導(dǎo)入圖片，作為資源存在工程里面。

如果不是，你先要把背景圖片放到資源里再調(diào)用。

又或者你的界面圖片被別的控件擋住了，你需要將別的控件的backcolor屬性改為transparent。

總之你想問什么問題，你得描述清楚。

請問這道VB.net怎么編程

1、作驗證，可用正則表達(dá)式、vb.net的自帶函數(shù)（相對簡單）

2、可采用排序方式

3、循環(huán)加限制條件

4 write

VB.net round問題

這應(yīng)該是由浮點(diǎn)數(shù)的誤差所造成的，你把kk設(shè)為雙精度浮點(diǎn)數(shù)，那么結(jié)果就是1.34

但是浮點(diǎn)數(shù)誤差與精度是無關(guān)的，雙精度也同樣存在，繼續(xù)測試你就會發(fā)現(xiàn)有趣的現(xiàn)象：

下面假定s為單精度浮點(diǎn)數(shù)變量，d為雙精度浮點(diǎn)數(shù)變量，則：

s = 1.345 Round(s, 2) = 1.35 （錯）

d = 1.345 Round(d, 2) = 1.34 （對）

s = 2.345 Round(s, 2) = 2.35 （錯）

d = 2.345 Round(d, 2) = 2.35 （錯）

s = 3.345 Round(s, 2) = 3.35 （錯）

d = 3.345 Round(d, 2) = 3.34 （對）

s = 4.345 Round(s, 2) = 4.34 （對）

d = 4.345 Round(d, 2) = 4.34 （對）

可以發(fā)現(xiàn)這錯誤的發(fā)生是毫無規(guī)律的，有時候真能讓人發(fā)瘋！

VB.net過程的調(diào)用

Sub過程實現(xiàn)：

Sub FactsSub(ByVal intN As Integer, ByRef result As Long)

Dim i As Integer

Dim lngResult As Long

lngResult = 1

For i = 1 To intN

lngResult *= i

Next

result = lngResult

End Sub

Private Sub btnSub_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSub.Click

Dim i As Integer

Dim sum As Long = 0

Dim result As Long

For i = 1 To 10

FactsSub(i, result)

sum += result

Next

MsgBox("過程實現(xiàn) 1! + 2! + 3! + … + 10! = " sum)

End Sub

Function函數(shù)實現(xiàn):

Function FactsFunction(ByVal intN As Integer) As Long

Dim i As Integer

Dim lngResult As Long

lngResult = 1

For i = 1 To intN

lngResult *= i

Next

Return lngResult

End Function

Private Sub btnFunction_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnFunction.Click

Dim i As Integer

Dim sum As Long = 0

For i = 1 To 10

sum += FactsFunction(i)

Next

MsgBox("函數(shù)實現(xiàn) 1! + 2! + 3! + … + 10! = " sum)

End Sub

VB.NET中的一個方法

用replace函數(shù)

Replace(expression, find, replacewith)

Replace函數(shù)語法有如下幾部分：

expression 字符串表達(dá)式，包含要替換的子字符串。

find 要搜索到的子字符串。

replacewith 用來替換的子字符串。

以你的要求:

str=Replace(A,"A","a")

如果你要做一個學(xué)生姓名對應(yīng)一個學(xué)生學(xué)號，你輸了姓名，學(xué)號自動就顯示出來了.

最好通過數(shù)據(jù)庫實現(xiàn).

select studentid from student where studentname=輸入姓名

用VB.NET編的計算器程序！

Public Class SimpleCalculator

Inherits System.Windows.Forms.Form

#Region " Windows 窗體設(shè)計器生成的代碼 "

Public Sub New()

MyBase.New()

'該調(diào)用是 Windows 窗體設(shè)計器所必需的。

InitializeComponent()

'在 InitializeComponent() 調(diào)用之后添加任何初始化

End Sub

'窗體重寫處置以清理組件列表。

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 窗體設(shè)計器所必需的

Private components As System.ComponentModel.IContainer

'注意：以下過程是 Windows 窗體設(shè)計器所必需的

'可以使用 Windows 窗體設(shè)計器修改此過程。

'不要使用代碼編輯器修改它。

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 = "結(jié)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 = "計算"

'

'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 = "簡單計算器"

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 '按鈕類型的變量

btn = sender '把產(chǎn)生該事件的按鈕對象賦值給btn

TextBox1.Text = TextBox1.Text + btn.Text '把該按鈕的Text屬性值連接到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屬性后連接一個空格、本按鈕的Text屬性值和一個空格

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

'發(fā)生錯誤轉(zhuǎn)移到標(biāo)號“ErrorPro”指定的行去執(zhí)行錯誤處理程序

On Error GoTo ErrorPro

Dim r As Decimal '保存計算結(jié)果的變量

Dim t As String = TextBox1.Text '用于保存文本框中的算術(shù)表達(dá)式

Dim space As Integer = t.IndexOf(" ") '搜索空格位置,如果沒有空格，返回值為0

'字符串的取子符方法，第二個參數(shù)小于0，則將產(chǎn)生錯誤號為5的異常，即過程參數(shù)不正確

Dim s1 As String = t.Substring(0, space) '通過取子串方法獲得第一個運(yùn)算數(shù)

Dim op As String = t.Substring(space + 1, 1) '通過取子串方法獲得運(yùn)算符

Dim s2 As String = t.Substring(space + 3) '通過取子串方法獲得第二個運(yùn)算數(shù)

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("輸入的運(yùn)算符有誤！")

Exit Sub

End Select

TextBox1.Text = CStr(r) '顯示結(jié)果

Exit Sub '退出過程

ErrorPro: '錯誤處理程序塊

Select Case Err.Number

Case 6 '除數(shù)為零時，或運(yùn)算溢出時的錯誤號

MsgBox("算術(shù)運(yùn)算溢出！", , "溢出提示")

TextBox1.Focus()

Exit Sub

Case 5 ' Substring過程的參數(shù)不符合要求的錯誤號

MsgBox("必須輸入運(yùn)算符和第二個運(yùn)算數(shù)！", , "運(yùn)算數(shù)少")

Exit Sub

Case Else

'其它情況顯示錯誤號和錯誤原因

MsgBox("錯誤號為" Err.Number Chr(10) Chr(13) "錯誤原因：" Err.Description)

Exit Sub

End Select

End Sub

End Class

當(dāng)前標(biāo)題：vb.net求導(dǎo)數(shù) vb求導(dǎo)函數(shù)
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