Question

vb.net 多线程 窗体 假死

代码如下

代码如下：

Private Sub btnLogin_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLogin.Click
Dim chkl As New Login
Dim th As New Threading.Thread(AddressOf chkl.ChkLogin)
chkl.UserName = UserName.Text.Trim.ToString
chkl.Pwd = Pwd.Text.Trim.ToString
th.Start()
UserName.Enabled = False
Pwd.Enabled = False
btnLogin.Enabled = False
LoginInfo.Text = "系统正在拉取用户数据，请稍后……"
End Sub

Delegate Sub SFM()
Sub ShowfrmMain()
If Me.InvokeRequired Then
Dim dh As New SFM(AddressOf ShowfrmMain)
Me.Invoke(dh)
Else
frmMain.Show()
Me.Close()
End If
End Sub

Class Login
Public UserName As String
Public Pwd As String

Function OpenDB()
Dim Conn As New OleDb.OleDbConnection("Provider=Microsoft.Jet.Oledb.4.0;Data Source=DataBase/DFZJOADB.MDB")
Try
Conn.Open()
Return Conn
Catch ex As Exception
Msg(ex.ToString)
End Try
End Function
Sub ChkLogin()
Dim sql As String = "select * from UserInfo where UserName='" & UserName & "'"
Dim DRL As New OleDbCommand(sql, OpenDB)
Dim ReadLoginData As OleDbDataReader = DRL.ExecuteReader()
ReadLoginData.Read()
If ReadLoginData.HasRows Then
If Pwd = ReadLoginData(2).ToString.Trim Then
System.Threading.Thread.Sleep(3000)
frmLogin.ShowfrmMain()
Else
Msg("您输入的密码错误！")
Exit Sub
End If
Else
Msg("没有该用户数据！")
Exit Sub
End If

End Sub
End Class

但是这样窗体就会假死，拖动不了，怎么解决这个问题呢？

Answer 1

并没有看出什么地方可能导致程序假死,这排版也太乱了.不妨调试一下程序,当出现你说的"假死"后暂停一下程序,看看线程都卡在哪里.
另外,从设计上来看,你这里并不需要多线程操作.

Answer 2

System.Threading.Thread.Sleep(3000)