Dim UserName As String = e.Form.Controls("UserName").Value
Dim s1,s2 As String
Dim cmd As New SQLCommand
Dim dt As DataTable
\'Dim dr As DataRow
cmd.C
If UserName = "" Then
    Messagebox.show("请选择用户!","提示",MessageBoxButtons.OK,MessageBoxIcon.Information)
    Return
End If
cmd.CommandText = "Select * From {用户表} Where [用户名] = \'" & UserName & "\'"
dt = cmd.ExecuteReader
If dt.DataRows.Count > 0 Then
s1=dt.DataRows(0)("密码")
e.Form.Controls("TextBox2").text=s1
s2=e.form.Controls("TextBox1").text
\'dr = dt.DataRows(0)
If  s1 = s2 Then
\'If e.Form.Controls("PassWord").text = dt.DataRows(0)("密码")  Then
    \'_UserName = UserName
    \'_UserGroup = dt.DataRows(0)("部门")
    e.Form.Close()
Else
\'    Messagebox.show("密码错误!","提示",MessageBoxButtons.OK,MessageBoxIcon.Information)

End If
End If

我把表里的值都取出来了，和我textbox1.text相等，也不执行退出

在：

If  s1 = s2 Then

的前面加一行：

messagebox.show(s1 = s2 )

把

messagebox.show(s1 = s2 )

改为

messagebox.show(s1.Length & "|" &  s2.legnth )

比较二者的长度，你可能会发现原因，通常是因为前后有空格所致。