如何在 DataGridView 中填充 DataTable

Question

I've created a WCF Web service that returns a simple DataTable to a Windows form on Button Click. I'm having issues displaying the returned data in a DataGridView.

This is the code in the Web Service using VB

    Public Function GetEmployees() As EmployeesData Implements IService1.GetEmployees

            Dim str As New String("Provider=Microsoft.ACE.OLEDB.12.0;Data Source =|DataDirectory|XXX.accdb;User Id=XXX;Password=XXX")
            Dim conn As New OleDbConnection(str)
            Dim cmd As New OleDbCommand("SELECT * FROM employees", conn)
            conn.Open()

            Dim sda = New OleDbDataAdapter

            cmd.Connection = conn
            sda.SelectCommand = cmd

            Using dt As New DataTable()
                Dim employees As New EmployeesData()
                sda.Fill(employees.EmployeesTable)
                Return employees
                conn.Close()
            End Using
        End Function

<DataContract()>
Public Class EmployeesData

    Public Sub New()
        EmployeesTable = New DataTable("EmployeesData")
    End Sub

    <DataMember()>
    Public Property EmployeesTable() As DataTable

End Class

And this is in the Windows form end on button click

     Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

            Dim client As Service1Client = New Service1Client()

            DataGridView1.DataSource = client.GetEmployees()
            DataGridView1.AutoGenerateColumns = True

        End Sub

Now, when I click the button, It's not populating the data to the grid.

Answer 1

Presumably this:

DataGridView1.DataSource = client.GetEmployees()

should be this:

DataGridView1.DataSource = client.GetEmployees().EmployeesTable

Answer 2

Your server code should look more like:

    Public Function GetEmployees() As EmployeesData Implements IEmployeesService.GetEmployees

        Dim con As New String("Provider=Microsoft.ACE.OLEDB.12.0;Data Source =|DataDirectory|XXX.accdb;User Id=XXX;Password=XXX")
        Dim cmd = "SELECT * FROM employees"

        Using sda As New OleDbDataAdapter(cmd, con)
          Dim employees As New EmployeesData()
          sda.Fill(employees.EmployeesTable)
        End Using
    End Function

And your client side code:

    Private Sub LoadEmployeesButton_Click(sender As Object, e As EventArgs) Handles LoadEmployeesButton.Click

        Dim client = New EmployeesServiceClient()

        EmployeesDataGridView.DataSource = client.GetEmployees().Employees 

    End Sub

• Just give a dataadaper a command string and a connection string- it knows how to do everything else itself so no need to clutter your code with it
• Stop leaving the default names of everything - you'll end up with a confusing mess of Button27, Label54, TextBox38 if you leave the default names. Renaming these things takes seconds