Giáo trình Visual Basic Tạo ứng dụng cụ thể

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

'

System.Windows.Forms.KeyPressEventArgs) Handles TextBox4.KeyPress Dim row As DataRow

If Asc(e.KeyChar) = 13 Then

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

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

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

str1 = Trim(TextBox6.Text) 'họ tên

If str1.Length > 0 Then

dong_dkien = "ho_ten like " + "'%" & str1 & "%'"

queryString1 = menh_de_chon + " " + dong_dkien

End If

End If

' -ngày sinh

If queryString1.Length = 0 Then

str1 = Trim(TextBox7.Text) 'họ tên

If str1.Length > 0 Then

dong_dkien = "ngay_sinh like " + "'" & str1 & "'"

queryString1 = menh_de_chon + " " + dong_dkien

End If

End If

' -thu

If (queryString1.Length = 0) Then

str1 = Trim(TextBox8.Text) '

If (CheckBox1.Checked = True And str1.Length > 0 And IsNumeric(str1)) Then

dong_dkien = "thu_nhap >=" & Val(str1)

queryString1 = menh_de_chon + " " + dong_dkien

End If

End If

If queryString1.Length = 0 Then

str1 = Trim(TextBox9.Text)

If (CheckBox2.Checked = True And str1.Length > 0 And IsNumeric(str1)) Then

dong_dkien = "thu_nhap <=" & Val(str1)

queryString1 = menh_de_chon + " " + dong_dkien

End If

End If

If (queryString1.Length = 0) Then

MsgBox(" cần có tiêu chuẩn tìm")

End If

adapter.SelectCommand = New OleDbCommand(queryString1, connect1)

dataSet1 = New DataSet

adapter.Fill(dataSet1, "table1")

If dataSet1.Tables("table1").Rows.Count > 0 Then

If GroupBox1.Visible = False Then

GroupBox1.Visible = True

End If

DataGridView1.DataSource = dataSet1.Tables("table1")

TextBox1.Clear()

TextBox2.Clear()

TextBox3.Clear()

TextBox4.Clear()

Else

'DataGridView1.DataSource = bang

MsgBox(" không tìm thấy")

End If

End Sub

Private Sub DataGridView1_CellMouseClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellMouseEventArgs) Handles DataGridView1.CellMouseClick

If bien_chon = 2 Then 'sua

cot = e.ColumnIndex

hang = e.RowIndex

TextBox1.Text = DataGridView1.Rows(hang).Cells(0).Value 'ID

TextBox2.Text = DataGridView1.Rows(hang).Cells(1).Value 'ho_ten TextBox3.Text = DataGridView1.Rows(hang).Cells(3).Value

TextBox4.Text = DataGridView1.Rows(hang).Cells(2).Value

End If

End Sub

Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button6.Click

bien_chon = 3

If GroupBox3.Visible = False Then

GroupBox3.Visible = True

End If

End Sub

Private Sub Button8_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button8.Click

'tra cứu thông tin

Dim queryString1 As String = ""

' -tính tổng thu nhập

If queryString1.Length = 0 Then

If CheckBox3.Checked = True Then

queryString1 = "SELECT SUM(thu_nhap) as tong_thu_nhap FROM table1"

tra_cuu_thong_tin(str1, queryString1)

Exit Sub

End If

End If

' -tính thu nhạp trung

If queryString1.Length = 0 Then

If CheckBox4.Checked = True Then

table1"

tra_cuu_thong_tin(str1, queryString1)

Exit Sub

End If

End If

' -tổng số cán

If queryString1.Length = 0 Then

If CheckBox5.Checked = True Then

queryString1 = "SELECT COUNT(*) as so_can_bo FROM table1"

tra_cuu_thong_tin(str1, queryString1)

Exit Sub

End If

End If

End Sub

Private Sub tra_cuu_thong_tin(ByVal connect_String As String, ByVal dong_query As String)

Dim adp As New OleDbDataAdapter(dong_query, connect_String)

Dim bang As New DataTable

Try

adp.Fill(bang)

DataGridView2.DataSource = bang

Catch ex As Exception

MsgBox(ex.Message)

End Try

End Sub

Private Sub Button9_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button9.Click

GroupBox3.Visible = False

End Sub

Private Sub Button10_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button10.Click

TextBox5.Clear()

TextBox6.Clear()

TextBox7.Clear()

TextBox8.Clear()

TextBox9.Clear()

' -xóa sach

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")

If GroupBox1.Visible = True Then

GroupBox1.Visible = False

End If

GroupBox2.Visible = False

End Sub

Private Sub Button11_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button11.Click

'kết thúc chương trình

End

End Sub

End Class

CÁC LƯU Ý

- Biến môi trường Application.StartupPath

- Tạo query qua hội thoại

- Cách sửa dữ liệu từ DataGridView

- Cách tạo hội thoại tiện lợi logic

- Tạo biến chọn bien_chon kiểm soát người sử dụng bấm gì

- Sử dụng GroupBox phân chia nhóm công việc để không bị rối

- Tham khảo thêm cách sort, find trên DataSet và DataGridview