مثال بسيط للعمليات الأساسية على قواعد البيانات في VB.NET - مطلوب تقييمكم

السلام عليكم ورحمه الله وبركاته ،

هذا احد الامثلة لدي قمت بعملها بنفسي ، ووضعت اليوم عليه بعض التطويرات البسيطة والمطلوب ان تقوموا بتقييم هذا المثال وطريقة كتابة الاكواد واستخدام كائنات ADO.NET فيه .

المثال يشتمل على :

1. عمليات الاضافة والتعديل والحذف
   
2. التنقل بين السجلات
   
3. استخدام DataGrid لعرض السجلات والتنقل بينها
   
4. عرض موقع السجل المعروض حاليا من اجمالي السجلات المستدعاه
   

:lol: :lol:

هنا نسخه من كود المثال كاملا :

Imports System.Data.OleDb
Public Class frmSample
	Dim Cn As New OleDbConnection("Provider=Microsoft.Jet.OleDb.4.0;Data Source=" & Application.StartupPath & "\db.mdb")
	Dim Da As New OleDbDataAdapter("SELECT * FROM Table1", Cn)
	Dim Ds As New DataSet
	Dim RowP As Integer = 0
	Dim bAdd As Boolean

	Private Sub Connect()
		If Not Cn.State = ConnectionState.Open Then Cn.Open()
	End Sub
	Private Sub ViewRecord(ByVal RowN As Integer)
		If Not Ds.Tables("Table1").Rows.Count < 0 Then
			txtID.Text = Ds.Tables("Table1").Rows(RowN).Item("ID")
			txtName.Text = Ds.Tables("Table1").Rows(RowN).Item("Name")
			txtAge.Text = Ds.Tables("Table1").Rows(RowN).Item("Age")

		End If
	End Sub
	Private Sub ViewPos()
		If Not Ds.Tables("Table1").Rows.Count <= 0 Then
			txtPos.Text = RowP + 1 & " From " & Ds.Tables("Table1").Rows.Count
		Else
			txtPos.Text = "There are now records in the Table ."
		End If
	End Sub
	Private Sub Enable(ByVal Enable As Boolean)
		With Me
			.txtID.ReadOnly = True
			.txtName.ReadOnly = Enable
			.txtAge.ReadOnly = Enable

			.btnMoveFrst.Enabled = Enable
			.btnMoveLast.Enabled = Enable
			.btnMoveNext.Enabled = Enable
			.btnMovePrev.Enabled = Enable

			.DataGridView1.Enabled = Enable
			.txtLog.Enabled = Enable
			.txtPos.Enabled = Enable

			.btnAddNew.Enabled = Enable
			.btnEdit.Enabled = Enable
			.btnDel.Enabled = Enable

			.btnSave.Enabled = Not Enable
			.btnCancel.Enabled = Not Enable

			If bAdd = True Then
				.btnSave.Enabled = Not Enable
				.btnCancel.Enabled = Not Enable
			End If
			If Ds.Tables("Table1").Rows.Count = 0 Then
				.btnEdit.Enabled = False
				.btnDel.Enabled = False
			End If
			Enable = Nothing
		End With
	End Sub

	Private Sub frmSample_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
		Connect()
		Da.Fill(Ds, "Table1")
		ViewRecord(0)
		ViewPos()
		Enable(True)

		DataGridView1.DataSource = Ds.Tables("Table1")
	End Sub

	Private Sub btnMoveFrst_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnMoveFrst.Click
		txtLog.Text = ""
		If Not Ds.Tables("Table1").Rows.Count = 0 Then
			ViewRecord(0)
			RowP = 0
		Else
			txtLog.Text = "There are no records to move to."
		End If
		ViewPos()

	End Sub

	Private Sub btnMovePrev_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnMovePrev.Click
		txtLog.Text = ""
		If Not Ds.Tables("Table1").Rows.Count = 0 Then

			Dim RowF As Integer
			RowF = RowP - 1
			If RowF < 0 Then
				txtLog.Text = "There are no records to move to."
			Else
				RowP = RowF
				ViewRecord(RowP)
			End If
		End If
		ViewPos()
	End Sub

	Private Sub btnMoveNext_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnMoveNext.Click
		txtLog.Text = ""
		If Not Ds.Tables("Table1").Rows.Count = 0 Then

			Dim RowF As Integer
			RowF = RowP + 1
			If RowF > Ds.Tables("Table1").Rows.Count - 1 Then
				txtLog.Text = "There are no records to move to."
			Else
				RowP = RowF
				ViewRecord(RowP)
			End If
		End If
		ViewPos()
	End Sub

	Private Sub btnMoveLast_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnMoveLast.Click
		txtLog.Text = ""
		If Not Ds.Tables("Table1").Rows.Count = 0 Then

			RowP = Ds.Tables("Table1").Rows.Count - 1
			ViewRecord(RowP)
		End If
		ViewPos()
	End Sub

	Private Sub btnAddNew_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAddNew.Click

		txtID.Text = ""
		txtName.Text = ""
		txtAge.Text = ""
		bAdd = True

		Enable(False)

	End Sub

	Private Sub btnEdit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnEdit.Click
		Enable(False)
		bAdd = False

	End Sub

	Private Sub btnCancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCancel.Click
		Enable(True)
		ViewRecord(RowP)
	End Sub

	Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
		Dim cmdB As New OleDbCommandBuilder(Da)

		If bAdd = True Then
			Dim addRow As DataRow

			addRow = Ds.Tables("Table1").NewRow
			addRow.Item("Name") = Trim(txtName.Text)
			addRow.Item("Age") = Trim(txtAge.Text)
			Ds.Tables("Table1").Rows.Add(addRow)
			Da.Update(Ds, "Table1")
			MsgBox("تمت عملية حفظ السجل الجديد المضاف")
		Else
			With Ds.Tables("Table1").Rows(RowP)
				.Item("Name") = Trim(txtName.Text)
				.Item("Age") = Trim(txtAge.Text)
			End With
			Da.Update(Ds, "Table1")
			MsgBox("تمت عملية حفظ تعديلات السجل الحالي " & RowP)
		End If
		Enable(True)
		ViewRecord(RowP)

	End Sub

	Private Sub btnDel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDel.Click
		Try
			If MsgBox("Are you shure ?", MsgBoxStyle.YesNo) = MsgBoxResult.Yes Then
				Ds.Tables("Table1").Rows(RowP).Delete()
				MsgBox("The Record " & RowP & " was deleted successfully")
				RowP -= 1
				ViewRecord(RowP)
			End If
		Catch ex As OleDbException
			MsgBox(ex.Message)
		End Try

	End Sub

	Private Sub DataGridView1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles DataGridView1.Click
		Dim rPos As Integer
		rPos = DataGridView1.CurrentRow.Index
		Try
			ViewRecord(rPos)
			ViewPos()
		Catch ex As Exception
			MsgBox(ex.Message)

		End Try

	End Sub

End Class

وكما قلت ارجو ابداء الرأي ، ماهي نقاط الضعف ان وجدت وما هي نقاط القوة ان وجدت ؟ وكيف يمكني التغلب على اي نقطة ضعف قد توجد وكيف يمكن تطوير اي جزء موجود فعليا من الكود ؟

أرجو ان لا تبخلو علي بالردود النافعة ودعوا عنكم ردود الشكر : رائع ، احسنت فهذه لا تغني ولا تسمن من جوع :rolleyes:

وبإنتظاركم : النبهاني :wacko:

DataBaseSample.rar