Windows Form ตอนที่ 3 : DataGridView Display Master-Detail (LINQ, Entity Framework)

    public partial class frmMain : Form
    {
        public frmMain()
        {
            InitializeComponent();
        }

        private void frmMain_Load(object sender, EventArgs e)
        {
            BindData();
        }

        private void BindData()
        {
            // Create new entities Object
            using (var db = new myDatabaseEntities())
            {

                // Get data from CUSTOMER
                var ds = (from c in db.CUSTOMER
                          select new
                          {
                              c.CUSTOMER_ID,
                              c.NAME,
                              c.EMAIL,
                              c.COUNTRY_CODE,
                              c.BUDGET,
                              c.USED
                          }).ToList();

                // Assign to DataGridView
                if (ds.Count > 0)
                {
                    this.myDataGridView.AutoGenerateColumns = false;
                    this.myDataGridView.AllowUserToAddRows = false;
                    this.myDataGridView.SelectionMode = DataGridViewSelectionMode.FullRowSelect;
                    this.myDataGridView.DataSource = ds;
                }

                // Summary Budget Column
                decimal iSumBudget = 0;
                foreach (DataGridViewRow row in this.myDataGridView.Rows)
                {
                    iSumBudget = iSumBudget + Convert.ToDecimal(row.Cells["BUDGET"].Value);
                }
                this.lblTotalBudget.Text = String.Format("Total Budget : {0}", iSumBudget.ToString("#,###.00"));

                // Summary Used Column
                decimal iSumUsed = 0;
                foreach (DataGridViewRow row in this.myDataGridView.Rows)
                {
                    iSumUsed = iSumUsed + Convert.ToDecimal(row.Cells["USED"].Value);
                }
                this.lblTotalUsed.Text = String.Format("Total Used : {0}", iSumUsed.ToString("#,###.00"));

            }
        }

        private void myDataGridView_CellClick(object sender, DataGridViewCellEventArgs e)
        {
            string strCustomerID = this.myDataGridView.Rows[e.RowIndex].Cells["CUSTOMER_ID"].Value.ToString();

            var form = new frmDetail();
            form._strCustomerID = strCustomerID; 
            form.ShowDialog();
        }

    }

    public partial class frmDetail : Form
    {
        public frmDetail()
        {
            InitializeComponent();
        }

        public string _strCustomerID { get; set; }

        private void frmDetail_Load(object sender, EventArgs e)
        {
            using (var db = new myDatabaseEntities())
            {
                // Get data from CUSTOMER
                var ds = (from c in db.CUSTOMER
                          where c.CUSTOMER_ID == _strCustomerID
                          select new
                          {
                              c.CUSTOMER_ID,
                              c.NAME,
                              c.EMAIL,
                              c.COUNTRY_CODE,
                              c.BUDGET,
                              c.USED
                          }).FirstOrDefault();

                // Display to label
                if (ds != null)
                {
                    this.lblCustomerID.Text = ds.CUSTOMER_ID;
                    this.lblName.Text = ds.NAME;
                    this.lblEmail.Text = ds.EMAIL;
                    this.lblCountryCode.Text = ds.COUNTRY_CODE;
                    this.lblBudget.Text = ds.BUDGET.ToString();
                    this.lblUsed.Text = ds.USED.ToString();
                }
            }
        }
    }

Public Class frmMain

    Private Sub frmMain_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        BindData()
    End Sub

    Private Sub BindData()
        ' Create new entities Object
        Using db = New myDatabaseEntities()

            ' Get data from CUSTOMER
            Dim ds = (From c In db.CUSTOMER
                      Select New With { _
                        c.CUSTOMER_ID, _
                        c.NAME, _
                        c.EMAIL, _
                        c.COUNTRY_CODE, _
                        c.BUDGET, _
                        c.USED _
                    }).ToList()

            ' Assign to DataGridView
            If ds.Count > 0 Then
                Me.myDataGridView.AutoGenerateColumns = False
                Me.myDataGridView.AllowUserToAddRows = False
                Me.myDataGridView.SelectionMode = DataGridViewSelectionMode.FullRowSelect
                Me.myDataGridView.DataSource = ds
            End If

            ' Summary Budget Column
            Dim iSumBudget As Decimal = 0
            For Each row As DataGridViewRow In Me.myDataGridView.Rows
                iSumBudget = iSumBudget + Convert.ToDecimal(row.Cells("BUDGET").Value)
            Next
            Me.lblTotalBudget.Text = String.Format("Total Budget : {0}", iSumBudget.ToString("#,###.00"))

            ' Summary Used Column
            Dim iSumUsed As Decimal = 0
            For Each row As DataGridViewRow In Me.myDataGridView.Rows
                iSumUsed = iSumUsed + Convert.ToDecimal(row.Cells("USED").Value)
            Next
            Me.lblTotalUsed.Text = String.Format("Total Used : {0}", iSumUsed.ToString("#,###.00"))
        End Using
    End Sub

    Private Sub myDataGridView_CellClick(sender As Object, e As DataGridViewCellEventArgs) Handles myDataGridView.CellClick
        Dim strCustomerID As String = Me.myDataGridView.Rows(e.RowIndex).Cells("CUSTOMER_ID").Value.ToString()

        Dim form = New frmDetail()
        form._strCustomerID = strCustomerID
        form.ShowDialog()
    End Sub

End Class

Public Class frmDetail

    Public Property _strCustomerID() As String
        Get
            Return m__strCustomerID
        End Get
        Set(value As String)
            m__strCustomerID = value
        End Set
    End Property
    Private m__strCustomerID As String

    Private Sub frmDetail_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Using db = New myDatabaseEntities()
            ' Get data from CUSTOMER
            Dim ds = (From c In db.CUSTOMER
                      Where c.CUSTOMER_ID = _strCustomerID
                      Select New With { _
                            c.CUSTOMER_ID, _
                            c.NAME, _
                            c.EMAIL, _
                            c.COUNTRY_CODE, _
                            c.BUDGET, _
                            c.USED _
                        }).FirstOrDefault()

            ' Display to label
            If Not IsNothing(ds) Then
                Me.lblCustomerID.Text = ds.CUSTOMER_ID
                Me.lblName.Text = ds.NAME
                Me.lblEmail.Text = ds.EMAIL
                Me.lblCountryCode.Text = ds.COUNTRY_CODE
                Me.lblBudget.Text = ds.BUDGET.ToString()
                Me.lblUsed.Text = ds.USED.ToString()
            End If
        End Using
    End Sub

End Class