Public Class StudentChangeTaskForm

    Private Sub StudentChangeTaskForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim strUser As String = LoginForm.TextUser.Text
        Dim strSQL As String = "select stask from student where suser='" + strUser + "'"
        TextOldTask.Text = DBOperation.Search(strSQL).Rows(0)("stask")
    End Sub

    Private Sub ButtonOK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ButtonOK.Click
        If TextNewTask.Text.Trim = "" Then
            MsgBox("請正確輸入新課題的名稱！", MsgBoxStyle.Exclamation, "錯誤")
            Exit Sub
        End If

        Dim response As Integer = MsgBox("確定選擇《" + TextNewTask.Text.Trim + "》作為新課題？", vbOKCancel + vbQuestion, "確認")
        If response = 2 Then
            Exit Sub
        End If

        Dim strUser As String = LoginForm.TextUser.Text
        Dim strSQL As String = "select s.sid, s.sname, t.tid from student s, teacher t where s.tid=t.tid and s.suser='" + strUser + "'"
        Dim UserTable As DataTable = DBOperation.Search(strSQL)
        Dim strSendid As String = UserTable.Rows(0)("sid")
        Dim strReceiveid As String = UserTable.Rows(0)("tid")
        Dim strName As String = UserTable.Rows(0)("sname")

        Dim strLid As String
        Dim nid As Integer
        strSQL = "select lid from leaveWord"
        UserTable = DBOperation.Search(strSQL)

        If UserTable.Rows.Count = 0 Then
            strLid = "l001"
        Else
            strLid = UserTable.Rows(UserTable.Rows.Count - 1)("lid")
            nid = Val(strLid.Substring(1)) + 1
            If nid < 10 Then
                strLid = "l00" + nid.ToString
            ElseIf nid < 100 Then
                strLid = "l0" + nid.ToString
            Else
                strLid = "l" + nid.ToString
            End If
        End If

        Dim strContent As String = "學生：" + strName + "希望將原課題《" + TextOldTask.Text + "》改成《" + TextNewTask.Text.Trim + "》，請指示！（按下下方同意或拒絕按鈕）"
        Dim contentByte() As Byte = System.Text.Encoding.Default.GetBytes(strContent)
        strSQL = "insert into leaveWord values('" + strLid + "', '" + strSendid + "', '" + strReceiveid + "', '" + Now().ToString + "', '2', @lcontent)"
        Dim strRow As String = "lcontent"

        If DBOperation.Insert(strSQL, strRow, contentByte) Then
            MsgBox("申請成功！請耐心等待老師的答復！", MsgBoxStyle.OkOnly, "改題申請")
        Else
            MsgBox("申請失敗！請重試！", MsgBoxStyle.Exclamation, "改題申請")
        End If
        TextNewTask.Text = ""
    End Sub

    Private Sub ButtonCancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ButtonCancel.Click
        Me.Close()
    End Sub
End Class