“System.NullReferenceException”类型的未经处理的异常在 课程设计__教务管理系统.exe 中发生 其他信息: 未将对象引用设置
Private Sub cmdOK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmd_OK.Click
If Username.Text = "" Then
MsgBox("请输入用户名!")
Username.Focus()
Exit Sub
End If
If Password.Text = "" Then
MsgBox("请输入密码!")
Password.Focus()
Exit Sub
End If
Dim icount As Integer
txtSQL = "SELECT * FROM 用户 WHERE 用户名 =‘" & Username.Text & "'"
icount = ExecuteSQL(txtSQL, Errormsg)
If icount = 0 Then
MsgBox("没有此用户,请重新输入用户名!", vbExclamation)
Username.Focus()
Exit Sub
If icount = -1 Then
MsgBox("程序出错!", vbExclamation)
Username.Focus()
Exit Sub
End If
End If
If Trim(Password.Text) = Trim(DBSet.Tables.Item(0).Rows.Item(0).Item("密码").ToString()) Then
username_OK = DBSet.Tables.Item(0).Rows.Item(0).Item("用户名")
frmMain.Show()
Finalize()
Else
MsgBox("密码不正确,请重新输入密码!", vbExclamation)
Password.Focus()
End If
End Sub