VB.NET如何對輸入的數(shù)據(jù)進行合法性檢驗,過濾不合法的數(shù)據(jù)代碼

合法性校驗有很多方法，要視情況而定，比如說可以用正則表達式，如果是數(shù)字，除了正則表達式，也可以用諸如TryParse這種方法。

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vb.net 點擊一個叫button1的按鈕 用COM1發(fā)送（接收） 假設八位數(shù)據(jù)位，有奇偶校驗位

這是我的簡單串口代碼：

Dim a As Integer

Dim b As Variant

Private Sub u_Click()

Text1.Text = "請先設置波特率與COM口?。?！"

End Sub

Private Sub Cbo1_Click()

On Error GoTo blak '打開串口發(fā)生錯誤，提示信息

If MSComm1.PortOpen = True And a = 1 Then

MSComm1.PortOpen = False '必須先關閉端口，再對端口進行設置

MSComm1.CommPort = cbo1.ListIndex + 1 '端口號從0開始，必須加1

Else '有必要

MSComm1.CommPort = cbo1.ListIndex + 1

End If '注釋的必須有，為第二次切換做準備，否則第二次換COM口會出問題

Exit Sub

blak:

MsgBox "串口不存在或被占用!", vbOKOnly, "提示信息" '必須是這種格式

End Sub

Private Sub Cbo2_Click() '單擊事件，不是change事件

MSComm1.Settings = 1200 * 2 ^ cbo2.ListIndex "n,8,1" '設置端口的波特率，連接符前后必須空一格

End Sub

Private Sub cmd1_Click()

a = a + 1

If a = 1 Then

cmd1.Caption = "關閉串口"

cbo1.Enabled = False

MSComm1.PortOpen = True '打開串口

ElseIf a = 2 Then

cmd1.Caption = "打開串口"

cbo1.Enabled = True

MSComm1.PortOpen = False '關閉串口

a = 0

End If

End Sub

Private Sub cmd2_Click()

Text1.Text = "" '清空接收區(qū)

Text2.SetFocus

End Sub

Private Sub cmd3_Click()

Text2.Text = "" '清空發(fā)送區(qū)

Text2.SetFocus

End Sub

Private Sub cmd4_Click()

Dim d As Integer

Dim e(0) As Byte 'outbyte 輸出字符

d = Val(Text2.Text)

e(0) = CByte(d)

MSComm1.OutBufferCount = 0 '清除發(fā)送緩沖區(qū)

MSComm1.Output = e '此命令執(zhí)行一次發(fā)送8字節(jié)

End Sub

Private Sub Form_Load()

cbo1.ListIndex = 0

cbo2.ListIndex = 0

MSComm1.OutBufferCount = 0

MSComm1.InBufferCount = 0

End Sub

Private Sub MSComm1_OnComm()

Select Case MSComm1.CommEvent '返回最近的通信過程

Case comEvReceive '接受的數(shù)據(jù)

c: b = MSComm1.Input

If Option1.Value = True Then

Text3.Text = Text1.Text Hex(b(0)) '首次不行，因為有字符

Text1.Text = Text3.Text " " '轉(zhuǎn)換一下

ElseIf Option2.Value = True Then

Text1.Text = Text1.Text b ""

End If

If MSComm1.InBufferCount 0 Then 'mscomm1.InBufferCount是緩沖區(qū)的數(shù)據(jù)數(shù)

GoTo c

End If

End Select

End Sub

Private Sub Option1_Click()

MSComm1.InputMode = comInputModeBinary '接收方式，十六進制

End Sub

Private Sub Option2_Click()

MSComm1.InputMode = comInputModeText '接收方式，字符格式

End Sub

Private Sub Text1_Change()

Text1.SelStart = Len(Text1.Text)

End Sub

VB.NET登陸界面。要驗證登錄用戶名和密碼是否正確。登陸后有管理員和普通用戶權限判斷。管理員只能登錄一

將用戶名，密碼，用戶類型存在數(shù)據(jù)庫中，登陸時比較輸入的值是否與數(shù)據(jù)庫相同即可。

VB.Net 怎么驗證 SQL2008 數(shù)據(jù)庫的ID與密碼

基礎類庫：

Imports Microsoft.VisualBasic

'執(zhí)行Access語句的封裝類。

Public Class AccessExecClass

Private conn As Data.OleDb.OleDbConnection

Private cmd As Data.OleDb.OleDbCommand

'創(chuàng)建類對象，并連接到數(shù)據(jù)庫。

Sub New()

If openAccess Then

Else

msgbox("open Access Fail.")

End If

End Sub

'創(chuàng)建類對象，并連接到數(shù)據(jù)庫。 '輸入帶目錄名稱的數(shù)據(jù)庫文件名稱：dbFileName，例如：“\DB數(shù)據(jù)庫\企業(yè)數(shù)據(jù)庫.aspx”

Sub New(ByVal dbFileName As String)

If OpenAccess(dbFileName) Then

Else

MsgBox("open Access Fail.")

End If

End Sub

Function OpenAccess() As Boolean

OpenAccess = False

'檢驗用戶的帳號密碼是否正確

Dim provider As String '= ConfigurationManager.ConnectionStrings("ConnectionString").ProviderName

provider = "Provider=Microsoft.Jet.OLEDB.4.0"

Dim database As String

database = "Data Source=" System.Web.HttpContext.Current.Server.MapPath("\數(shù)據(jù)庫.aspx") ";Persist Security Info=true"

conn = New Data.OleDb.OleDbConnection(provider ";" database)

conn.Open()

OpenAccess = True

End Function

Function OpenAccess(ByVal dbFileName As String) As Boolean

OpenAccess = False

'檢驗用戶的帳號密碼是否正確

Dim provider As String '= ConfigurationManager.ConnectionStrings("ConnectionString").ProviderName

provider = "Provider=Microsoft.Jet.OLEDB.4.0"

Dim database As String

database = "Data Source=" System.Web.HttpContext.Current.Server.MapPath(dbFileName) ";Persist Security Info=true"

conn = New Data.OleDb.OleDbConnection(provider ";" database)

conn.Open()

OpenAccess = True

End Function

'關閉數(shù)據(jù)庫。

Sub CloseAccess()

cmd = Nothing

conn.Close()

End Sub

'執(zhí)行一條Access語句，執(zhí)行成功就返回True。

Function ExecAccessString(ByVal AccessStr As String) As Boolean

cmd = New Data.OleDb.OleDbCommand(AccessStr, conn)

cmd.ExecuteNonQuery()

'Dim aa As Data.OleDb.OleDbDataReader = cmd.ExecuteReader

ExecAccessString = True

End Function

'返回讀取到的數(shù)據(jù)，注意是用地址傳遞方式返回

Sub ExecAccessString(ByVal AccessStr As String, ByRef AccessReader As Data.OleDb.OleDbDataReader)

cmd = New Data.OleDb.OleDbCommand(AccessStr, conn)

cmd.ExecuteNonQuery()

AccessReader = cmd.ExecuteReader

End Sub

End Class

登陸代碼：

Protected Sub LinkButton1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles LinkButton1.Click

Dim wl As New WebLog '用戶登錄記錄開始，僅對購買了Log 功能的用戶，才開放此功能，否則不會實際記錄Log

Dim sql As String

Dim aDB As New AccessExecClass

Dim mypw As String

Label1.Visible = False

Label2.Visible = False

Label3.Visible = False

Label4.Visible = False

'沒有輸入時,不能進行登陸

If TextBox1.Text = "" Then

Label1.Visible = True

Return

End If

If TextBox2.Text = "" Then

Label2.Visible = True

Return

End If

If TextBox3.Text = "" Then

Label3.Visible = True

Return

End If

If TextBox3.Text = TextBox4.Text Then

Else

Label3.Visible = True

Return

End If

Dim iRnd As Integer = Rnd(10) * 100

TextBox3.Text = ""

TextBox4.Text = iRnd.ToString

'Dim iRnd As Integer = Rnd(10) * 100

'注意:此處需要加入防止注入分析,包含'的肯定是特別語句,講拒絕.

If TextBox1.Text.IndexOf("'") 0 Or TextBox2.Text.IndexOf("'") 0 Then

TextBox1.Text = "不能輸入非法字符,將強制清空"

TextBox2.Text = ""

Else

Dim pw As New MD5EnCode(13, 19) ' '2次加密

sql = "select 權限組號,ID , 密碼 from 編輯人數(shù)據(jù) where 編輯姓名='" + TextBox1.Text + "'"

Dim aa As Data.OleDb.OleDbDataReader '= cmd.ExecuteReader

aDB.ExecAccessString(sql, aa)

If aa.Read() Then

'密碼正確()

'sql = aa(2)'需要特別注意：只能單向解密，不能直接轉(zhuǎn)換

mypw = pw.simDeCode(pw.simDeCode(aa(2)))

If TextBox2.Text = mypw Then

Session("LOGIN_Name") = TextBox1.Text '設置登錄后的用戶名稱

Session("Login_Group") = aa(0) 'cmd.ExecuteScalar '設置登錄后的權限級別

Session("Login_ID") = aa(1) 'cmd.ToString

'cmd = Nothing

'conn.Close()

Call wl.NewLog("登錄", "管理員成功登錄")

Response.Redirect("../WebManages/Default.ASPX")

Else

'密碼錯誤()

sql = sql.Replace("'", "【單引號】")

sql = sql.Replace(",", "【逗號】")

Call wl.NewLog("登錄", "管理員失敗的登錄", TextBox1.Text, sql.Replace("""", "【雙引號】"), "")

Label4.Visible = True

End If

Else

'密碼錯誤()

sql = sql.Replace("'", "【單引號】")

sql = sql.Replace(",", "【逗號】")

Call wl.NewLog("登錄", "管理員失敗的登錄", TextBox1.Text, sql.Replace("""", "【雙引號】"), "")

Label4.Visible = True

End If

End If

End Sub

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