MySQL + VB.NET - TabControlと複数のDataGridviews

Question

私は自分のDataGridViewに問題があります。実際には8つのタブを持つTabControlを持つフォームがあり、各タブにはDataGridViewコントロールがあります。フォームの読み込み時に問題が発生します.3つのDataGridViewだけが3つの特定のものではなく、3つのコードが最初に配置されます。私はそれらを手動で設定し、mysqlクエリを実行して、DataTableを充填してから、データソースをDataTableと等しくします。

アイデア？

Imports MySql.Data.MySqlClient 
Imports System.Data 

Public Class frmMantenimiento 
    Dim conn As MySqlConnection 
    Dim myCommand As New MySqlCommand 
    Dim myAdapter As New MySqlDataAdapter 
    Dim dataEmp As New DataTable 
    Dim dataNomi As New DataTable 
    Dim dataPres As New DataTable 
    Dim dataGast As New DataTable 
    Dim dataAmon As New DataTable 
    Dim dataHora As New DataTable 
    Dim SQL As String 

    Public Sub FillEmps() 
     conn = New MySqlConnection("Data Source=localhost; user id=root; password=; database=arj;") 

     myCommand.Connection = conn 
     SQL = "SELECT IDEmpleado as ID, Nombre, Cargo FROM Empleados" 

     Try 
      conn.Open() 

      Try 
       myCommand.Connection = conn 
       myCommand.CommandText = SQL 

       myAdapter.SelectCommand = myCommand 
       myAdapter.Fill(dataEmp) 

       dgvConsEmp.DataSource = dataEmp 

       dgvConsEmp.Columns(0).Width = 30 
       dgvConsEmp.Columns(1).Width = 200 
       dgvConsEmp.Columns(2).Width = 200 

      Catch myerror As MySqlException 
       MsgBox("Ocurrió un error leyendo la base de datos: " & myerror.Message) 
      End Try 
     Catch myerror As MySqlException 
      MessageBox.Show("Ocurrió un error conectando a la base de datos: " & myerror.Message) 
     Finally 
      If conn.State <> ConnectionState.Closed Then conn.Close() 
     End Try 
    End Sub 

    Public Sub FillNom() 
     conn = New MySqlConnection("Data Source=localhost; user id=root; password=; database=arj;") 

     myCommand.Connection = conn 
     SQL = String.Empty 
     SQL = "SELECT IDNomina as ID, Fecha, MontoBruto as 'Monto Bruto', MontoNeto as 'Monto Neto', CantidadEmpleados as Empleados FROM Nomina" 

     Try 
      conn.Open() 

      Try 
       myCommand.Connection = conn 
       myCommand.CommandText = SQL 

       myAdapter.SelectCommand = myCommand 
       myAdapter.Fill(dataNomi) 

       dgvConsNomi.DataSource = dataNomi 

       dgvConsNomi.Columns(0).Width = 30 

      Catch myerror As MySqlException 
       MsgBox("Ocurrió un error leyendo la base de datos: " & myerror.Message) 
      End Try 
     Catch myerror As MySqlException 
      MessageBox.Show("Ocurrió un error conectando a la base de datos: " & myerror.Message) 
     Finally 
      If conn.State <> ConnectionState.Closed Then conn.Close() 
     End Try 
    End Sub 

    Public Sub FillPres() 
     conn = New MySqlConnection("Data Source=localhost; user id=root; password=; database=arj;") 

     myCommand.Connection = conn 
     SQL = String.Empty 
     SQL = "SELECT IDPrestamo as ID, IDEmpleado as 'ID Empleado', MontoInicial as Monto, Fecha, MontoDescuento as Descuento, FormaDescuento as Recurrencia, Status FROM Prestamos" 

     Try 
      conn.Open() 

      Try 
       myCommand.Connection = conn 
       myCommand.CommandText = SQL 

       myAdapter.SelectCommand = myCommand 
       myAdapter.Fill(dataPres) 

       dgvConsPres.DataSource = dataPres 

       dgvConsPres.Columns(0).Width = 30 

      Catch myerror As MySqlException 
       MsgBox("Ocurrió un error leyendo la base de datos: " & myerror.Message) 
      End Try 
     Catch myerror As MySqlException 
      MessageBox.Show("Ocurrió un error conectando a la base de datos: " & myerror.Message) 
     Finally 
      If conn.State <> ConnectionState.Closed Then conn.Close() 
     End Try 
    End Sub 

    Public Sub FillGast() 
     conn = New MySqlConnection("Data Source=localhost; user id=root; password=; database=arj;") 

     myCommand.Connection = conn 
     SQL = String.Empty 
     SQL = "SELECT IDGasto as ID, IDEmpleado as 'ID Empleado', Monto, Fecha, Concepto, IDUsuario as Creador FROM GastosEmpleados" 

     Try 
      conn.Open() 

      Try 
       myCommand.Connection = conn 
       myCommand.CommandText = SQL 

       myAdapter.SelectCommand = myCommand 
       myAdapter.Fill(dataGast) 

       Me.dgvConsGast.DataSource = dataGast 

       Me.dgvConsGast.Columns(0).Width = 30 

      Catch myerror As MySqlException 
       MsgBox("Ocurrió un error leyendo la base de datos: " & myerror.Message) 
      End Try 
     Catch myerror As MySqlException 
      MessageBox.Show("Ocurrió un error conectando a la base de datos: " & myerror.Message) 
     Finally 
      If conn.State <> ConnectionState.Closed Then conn.Close() 
     End Try 
    End Sub 

    Public Sub FillAmon() 
     conn = New MySqlConnection("Data Source=localhost; user id=root; password=; database=arj;") 

     myCommand.Connection = conn 
     SQL = "SELECT IDAmonestacion as ID, TipoAmonestacion as Tipo, Descripcion, IDUsuario as Creador FROM Amonestaciones" 

     Try 
      conn.Open() 

      Try 
       myCommand.Connection = conn 
       myCommand.CommandText = SQL 

       myAdapter.SelectCommand = myCommand 
       myAdapter.Fill(dataAmon) 

       dgvConsAmon.DataSource = dataAmon 

       dgvConsAmon.Columns(0).Width = 30 

      Catch myerror As MySqlException 
       MsgBox("Ocurrió un error leyendo la base de datos: " & myerror.Message) 
      End Try 
     Catch myerror As MySqlException 
      MessageBox.Show("Ocurrió un error conectando a la base de datos: " & myerror.Message) 
     Finally 
      If conn.State <> ConnectionState.Closed Then conn.Close() 
     End Try 
    End Sub 

    Public Sub FillHora() 
     conn = New MySqlConnection("Data Source=localhost; user id=root; password=; database=arj;") 

     myCommand.Connection = conn 
     SQL = "SELECT IDControlHorario as ID, IDEmpleado as 'ID Empleado', Fecha, Hora FROM ControlHorario" 

     Try 
      conn.Open() 

      Try 
       myCommand.Connection = conn 
       myCommand.CommandText = SQL 

       myAdapter.SelectCommand = myCommand 
       myAdapter.Fill(dataHora) 

       dgvConsHora.DataSource = dataHora 

       dgvConsHora.Columns(0).Width = 30 

      Catch myerror As MySqlException 
       MsgBox("Ocurrió un error leyendo la base de datos: " & myerror.Message) 
      End Try 
     Catch myerror As MySqlException 
      MessageBox.Show("Ocurrió un error conectando a la base de datos: " & myerror.Message) 
     Finally 
      If conn.State <> ConnectionState.Closed Then conn.Close() 
     End Try 
    End Sub 


    Private Sub frmMantenimiento_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
     FillEmps() 
     FillNom() 
     FillPres() 
     FillGast() 
     FillAmon() 
     FillHora() 
    End Sub 

Answer 1

リファクタリングできるコードの複製がたくさんあります。しかし、根本的な原因は、それぞれFillX()メソッドでmyCommandとmyAdapterの変数を再初期化していないということです。ですから、conn,myCommand、myAdapter、SQLという変数を、それぞれFillX()メソッドのローカル変数にすることから始めます。

次にDRY（Do not Repeat Yourself）の原則を適用し、重複したコードを削除するコードをリファクタリングします。