Giáo trình Visual Basic Tạo ứng dụng cụ thể

BÀI 15 - THIẾT KẾ MỘT ỨNG DỤNG CỤ THỂ
Imports System.Windows
Imports System.Data.OleDb
Public Class Form1
'======các biến mo tả chung
Dim dataSet1 As DataSet = New DataSet
Dim adapter As New OleDbDataAdapter()
Dim str1 As String = "provider=Microsoft.Jet.OLEDB.4.0; data source=" &
Application.StartupPath & "\ho_so.mdb"
Dim connect1 As OleDbConnection = New OleDbConnection(str1)
Dim bien_chon As Integer = 0 '1- nhap; 2- sửa; 3-tra cứu; 4-report
Dim hang, cot As Integer
'======================================
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
MonthCalendar1.Visible = False
GroupBox1.Visible = False
GroupBox2.Visible = False
GroupBox3.Visible = False
'connect1.Open()
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
'nhâp Data
Dim bang As New DataTable
bien_chon = 1 'nhap
GroupBox1.Visible = True
Dim queryString As String = "select * from table1 where ho_ten='$' "
adapter.SelectCommand = New OleDbCommand(queryString, connect1)
adapter.Fill(dataSet1, "table1")

DataGridView1.DataSource = dataSet1.Tables("table1")
DataGridView1.Refresh()
TextBox1.Clear()
TextBox2.Clear()
TextBox3.Clear()
TextBox4.Clear()
TextBox1.Focus()
End Sub
Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As
System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
'nhập mã ID
If Asc(e.KeyChar) = 13 Then
If Len(Trim(TextBox1.Text)) > 0 Then
TextBox2.Focus()
Else
TextBox1.Focus()
End If
End If
End Sub
'--------------------
Private Sub TextBox2_KeyPress(ByVal sender As Object, ByVal e As
System.Windows.Forms.KeyPressEventArgs) Handles TextBox2.KeyPress
If Asc(e.KeyChar) = 13 Then
If Len(Trim(TextBox2.Text)) > 0 Then
TextBox3.Focus()
Else
TextBox2.Focus()
End If
End If
End Sub

'---------------------
Private Sub TextBox3_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles TextBox3.Click
MonthCalendar1.Visible = True
End Sub
'

Private Sub TextBox4_KeyPress(ByVal sender As Object, ByVal e As
System.Windows.Forms.KeyPressEventArgs) Handles TextBox4.KeyPress
Dim row As DataRow
If Asc(e.KeyChar) = 13 Then
'-----------nhap-----
If bien_chon = 1 Then
row = dataSet1.Tables("table1").NewRow
If Len(Trim(TextBox3.Text)) > 0 Then
row("ID") = TextBox1.Text
row("ho_ten") = TextBox2.Text
row("ngay_sinh") = TextBox3.Text
row("thu_nhap") = Val(TextBox4.Text)
dataSet1.Tables("table1").Rows.Add(row)
DataGridView1.DataSource = dataSet1.Tables("table1")
DataGridView1.Refresh()
TextBox1.Clear()
TextBox2.Clear()
TextBox3.Clear()
TextBox4.Clear()
TextBox1.Focus()
End If
End If
'-----------sua ---------------------

If bien_chon = 2 Then
row = dataSet1.Tables("table1").NewRow
If Len(Trim(TextBox3.Text)) > 0 Then
DataGridView1.Rows(hang).Cells(0).Value = TextBox1.Text
DataGridView1.Rows(hang).Cells(1).Value = TextBox2.Text
DataGridView1.Rows(hang).Cells(3).Value = TextBox3.Text
DataGridView1.Rows(hang).Cells(2).Value = TextBox4.Text
row = dataSet1.Tables("table1").Rows(hang)
row("ID") = TextBox1.Text
row("ho_ten") = TextBox2.Text
row("ngay_sinh") = TextBox3.Text
row("thu_nhap") = Val(TextBox4.Text)
DataGridView1.Refresh()
TextBox1.Clear()
TextBox2.Clear()
TextBox3.Clear()
TextBox4.Clear()
TextBox1.Focus()
End If
End If
End If
End Sub
'-------------------------
Private Sub MonthCalendar1_DateSelected(ByVal sender As Object, ByVal e
As System.Windows.Forms.DateRangeEventArgs) Handles
MonthCalendar1.DateSelected
Dim date1 As Date
Dim dongngay As String = ""
date1 = e.Start
dongngay = Convert.ToString(date1.Day) + "/" +

Convert.ToString(date1.Month) + "/" + Convert.ToString(date1.Year)
TextBox3.Text = dongngay
MonthCalendar1.Visible = False
TextBox4.Focus()
End Sub
'--------------------
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button2.Click
'sửa data
bien_chon = 2 'sửa
'-----------------------
If GroupBox2.Visible = False Then
GroupBox2.Visible = True
End If
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button3.Click
'ghi lại data
Dim builder As OleDbCommandBuilder = New
OleDbCommandBuilder(adapter)
adapter.Update(dataSet1, "table1")
MsgBox("ghi xong")
DataGridView1.ClearSelection()
End Sub
Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button4.Click
'thôi nhập sửa
'-----------------xóa sach DataGridView1------------
Dim queryString As String = "select * from table1 where ho_ten='$' "
adapter.SelectCommand = New OleDbCommand(queryString, connect1)

adapter.Fill(dataSet1, "table1")
DataGridView1.DataSource = dataSet1.Tables("table1")
GroupBox1.Visible = False
GroupBox2.Visible = False
End Sub
Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button5.Click
'OK sửa
Dim queryString1 As String = ""
Dim menh_de_chon As String = "select * from table1 where "
Dim dong_dkien As String = ""
Dim str1 As String
If queryString1.Length = 0 Then
str1 = Trim(TextBox5.Text) 'mã số
If str1.Length > 0 Then
dong_dkien = "ID like " + "'" & str1 & "'"
queryString1 = menh_de_chon + " " + dong_dkien
End If
End If
'------------họ tên
If queryString1.Length = 0 Then