vb.net取子串 vbnet字符串截取-成都快上网建站

vb.net取子串 vbnet字符串截取

用VB.NET编的计算器程序!

Public Class SimpleCalculator

10年积累的成都网站建设、成都网站设计经验,可以快速应对客户对网站的新想法和需求。提供各种问题对应的解决方案。让选择我们的客户得到更好、更有力的网络服务。我虽然不认识你,你也不认识我。但先网站策划后付款的网站建设流程,更有芙蓉免费网站建设让你可以放心的选择与我们合作。

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

Visual Basic.Net Left函数问题

减去字符串,很简单

Dim ss1 As String

ss1 = ss1.Replace(ss2, "")

ss1.Replace(ss2, "") 的意思就是,把ss1字符串中的ss2都替换成空字符,得到的结果仍然赋给ss1

至于你那个left,VB.net似乎没有这个函数了,你写那个Left,实际是窗体的位置属性,连编译都无法编译,要取子字符串,用

ss1 = ss1.Substring(0, 1)

参数0表示从第几个字符开始,1表示取多少个字符

vb.net 判断输入内容的固定位置是不是指定值

使用VB提供的取子串函数Mid(S,k,n);

函数Mid(S,k,n)的功能,从指定的字符串表达式S的第k位开始取连续的n个字符。

例如:S = "1234567890",Mid(S,1,3) ,返回"123"

例如:S = "1234567890",Mid(S,3,7) ,返回"3456789"

等等;

结合VB的IF语句,就可以实现你的要求;

If Mid("1234567890",1,3) = "123" Then

MsgBox("正确")

Else

MsgBox("错误")

End If

vb.net截取字符串的问题

可以如下截取056

Private Sub Command1_Click()

a = "123.45056"

Me.Caption = Mid(a, InStr(a, "056"), 3)

End Sub


分享标题:vb.net取子串 vbnet字符串截取
URL分享:http://kswjz.com/article/hphoss.html
扫二维码与项目经理沟通

我们在微信上24小时期待你的声音

解答本文疑问/技术咨询/运营咨询/技术建议/互联网交流