用戶登錄驗證程序——VB.NET

用戶登錄驗證程序，提供一個Login UI使用ADO.NET把數據保存到DB中

Introduction

實現用戶登錄功能，UI使用WinForm提供LoginForm,然后建一個User表保存用戶信息（UserName, PassWrd, UserActive, Comment），使用Linq對User表進行查詢。

plainText = CryptographyUtils.Decrypt(CryptographyUtils.CreateSymmAlgoRC2(),cipherText, "JK_huangJK_huang", 128CryptographyUtils.CreateSymmAlgoRC2(),cipherText, "JK_huangJK_huang", 128);

Backgroud

使用Visual studio2008,sql server 2005開發

The Definition of User Table

 SET ANSI_NULLS ON

GO

SET QUOTED_IDENTIFIER ON

GO

CREATE TABLE [dbo].[t_UserInfo](

    [UserName] [nvarchar](20) NOT NULL,

    [PassWrd] [nvarchar](20) NOT NULL,

    [UserActive] [bit] NOT NULL,

    [Comment] [nvarchar](50) NULL,

 CONSTRAINT [PK_t_UserInfo] PRIMARY KEY CLUSTERED 

(

    [UserName] ASC

)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]

) ON [PRIMARY]

Validing the user and Passing Data to Database

上傳數據方法，當CheckReg.Checked = True是創建新用戶，False時檢驗當前用戶是否有效

    Private Sub OK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OK.Click
        Dim loginDS As New TestInfoDataSet.t_UserInfoDataTable
        Dim loginDA As New TestInfoDataSetTableAdapters.t_UserInfoTableAdapter

        If CheckReg.Checked = True Then
            Try
                loginDA.Insert(comUser.Text.ToString(), txtPW.Text.ToString(), True, "")
            Catch ex As Exception
                MessageBox.Show("The UserName already exist", "Information", MessageBoxButtons.OK, MessageBoxIcon.Information)
                comUser.Focus()
                comUser.Text = ""
            Finally
                Me.ClearForm()
            End Try
        Else
            Try
                loginDA.FillByUserData(loginDS, comUser.ToString(), txtPW.ToString())
                Check_Details()
            Catch ex As Exception
                MsgBox("Invalid User Name", MsgBoxStyle.Critical, "Error")
            End Try
        End If

End Sub

使用Linq查詢用戶是否存在User表中

    Private Sub Check_Details()
        Dim PWord As String = Me.txtPW.Text.ToString.Trim

        Dim CheckDA As New TestInfoDataSetTableAdapters.t_UserInfoTableAdapter
        Dim query = From check In CheckDA.GetData _
                    Select check.UserName, check.PassWrd, check.UserActive _
                    Where UserName = UName AndAlso PassWrd = PWord _
                                AndAlso UserActive = True
        If query.Count() = 1 Then
            MessageBox.Show("confirmed", "Information", MessageBoxButtons.OK, MessageBoxIcon.Information)
            Me.ClearForm()
        Else
            MessageBox.Show("Password Is Incorrect or no longer Valid", "Incorrect Password", MessageBoxButtons.OK, MessageBoxIcon.Information)
            txtPW.Focus()
            txtPW.Text = ""

        End If

End Sub

Data Valide

進行輸入操作時是全角輸入就要轉換為半角輸入，這里使用兩種方法進行全角到半角的轉換

1.處理輸入后的數據2.只輸入半角字符

 Private Function ToDBC(ByVal tmpStr As String) As String
        Dim i As Integer = 0

        Dim c() As Char = tmpStr.ToCharArray()
        Dim length As Integer = c.Length - 1

        For i = 0 To length
            If c(i) = "　" Then
                c(i) = CChar(" ")
            ElseIf AscW(c(i)) > 65280 And AscW(c(i)) < 65375 Then
                c(i) = ChrW(AscW(c(i)) - 65248)
            End If
        Next
        Return CStr(c)
    End Function
End Class

2.關閉輸入法

Me.comUser.ImeMode = Forms.ImeMode.Close ‘直接關閉全角輸入

用戶登錄UI

https://files.cnblogs.com/rush/登錄檢驗程序.rar

The experience of project

Visual Basic 不會在 Char 類型和數值類型之間直接轉換。可以使用 Asc 或 AscW 函數將 Char 值轉換為表示其碼位的 Integer。可以使用 Chr 或 ChrW 函數將 Integer 值轉換為具有該碼位的 Char。

本文基于署名 2.5 中國大陸許可協議發布，歡迎轉載，演繹或用于商業目的，但是必須保留本文的署名 JK_Rush （包含鏈接），具體操作方式可參考此處。如您有任何疑問或者授權方面的協商，請給我留言。

posted @ 2010-11-07 18:34 JK_Rush 閱讀(6637) 評論(1) 收藏舉報

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