小第做毕业设计遇到问题,特向各位请教!谢谢
想做一个登陆的在ComboBox1控件里显示用户名
请大家指导．小弟急，，，，
登陆窗体代码
Dim User As String
Dim Code As String
Dim sqlstr As String
Private Sub login_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'DataSet1.Clear()
'SqlDataAdapter1.Fill(DataSet1, "Admin_Table")
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
If MsgBox("您真的不登陆母婴用品商店管理系统吗？", _
MsgBoxStyle.YesNo + MsgBoxStyle.Question, "退出登录系统") _
= MsgBoxResult.Yes Then
Application.Exit()
Else
Exit Sub
End If
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
'对用户名和密码进行判断，进而对本项目操作时进行限制，即对功能的限制，
User = Me.ComboBox1.Text.Trim
Code = Me.TextBox1.Text.Trim
sqlstr = "SELECT * FROM Admin_Table WHERE UserName= " & _
"'" & User & "' AND Password='" & Code & "'"
Dim objDataRow As DataRow
Try
objDataRow = GetDataFromDB(sqlstr).Tables(0).Rows(0)
Catch
MsgBox("密码和账号不符，请重试，并检查该账号是否存在。", _
MsgBoxStyle.Information + MsgBoxStyle.OKOnly, "系统登录失败")
Me.TextBox1.Text = ""
Exit Sub
End Try
Dim MainForm As New Form2
MainForm.ShowDialog()
Me.Close()
End Sub
Module.VB文件
++++++++++++++
Imports System.Data
Imports System.DBNull
Imports System.Data.SqlClient
Module Module1
'用户登陆名
Dim User As String
Public objDataSet As DataSet1
'定义一个数据集对象
Public objDataAdpter As SqlDataAdapter
'定义一个数据适配器对象
Public objSqlConnection As SqlConnection = New _
SqlConnection("data source=PJM\PJMSQL;initial catalog=MYDatabase;user id=sa;password=123")
'定义一个数据连接对象，并初始化
'定义一个当前的绑定管理对象
Public UserSqlstr As String = "SELECT ID,UserName,AdminYS FROM Admin_Table"
Public Function GetDataFromDB(ByVal sqlstr As String) As DataSet
objDataSet = New DataSet1
objDataSet.Clear()
'实例化一个数据集对象
Try
objSqlConnection.Open()
'打开数据库连接
objDataAdpter = New SqlDataAdapter(sqlstr, objSqlConnection)
'将数据库的数据映射到数据适配器
objDataAdpter.Fill(objDataSet)
'填充数据集的数据
objSqlConnection.Close()
'关闭数据连接，这一点很重要
Catch
MsgBox("错误号：" & Err.Number & "错误描述：" & Err.Description)
End Try
Return objDataSet
objDataSet = Nothing
End Function
Public Function UpdateData(ByVal sqlstr As String) As Boolean
Dim objCommand As SqlCommand = New SqlCommand
Try
objSqlConnection.Open()
objCommand.Connection = objSqlConnection
objCommand.CommandText = sqlstr
objCommand.CommandType = CommandType.Text
objCommand.ExecuteNonQuery()
objSqlConnection.Close()
Catch
MsgBox("错误号：" & Err.Number & "错误描述：" & Err.Description)
Return False
End Try
Return True
End Function
End Module
[解决办法]
把检索出来的DataSet
分别赋给ComboBox1的valueMeber和TextMeber
试试。
[解决办法]
("您真的不登陆母婴用品商店管理系统吗？", _
这句话有创意
[解决办法]
Dim table As New DataTable table.Columns.Add("ID", GetType(Integer)) table.Columns.Add("UserName") table.Rows.Add(New Object() {0, "老王"}) table.Rows.Add(New Object() {1, "小李"}) table.AcceptChanges() With Me.ComboBox1 .DataSource = table .DisplayMember = "UserName" .ValueMember = "ID" End With
[解决办法]