显示的 Datagridview 数据与 datagriview 具有的数据不同

Question

我有一个主要表单（form1），它等待接收信息

Private Sub SerialPort1_DataReceived(sender As System.Object, e As SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
    Dim output As String
    output = SerialPort1.ReadLine()
    Converter(output) 'format what was received
    Submit() 'submit into db
    Form3.BackgroundWorker1.RunWorkerAsync()
    Thread.Sleep(2000)
    Application.DoEvents()
End Sub

并将信息处理/提交到数据库中，如果 form3 已打开（该条件尚未测试，但我一直在测试时确保在通过串行端口发送数据之前打开 form3）它应该更新form3中的datagridview。

Public Class Form3
        Delegate Sub dgvDelegate()
        Sub fill()
            tabela_dispensa.Rows.Clear()
            Conectar(conn, myCommand) ' connect to db
            myCommand.CommandText = "select dispensa.*,produto.Descrição from dispensa join produto on dispensa.PLU = produto.PLU"
            result = myCommand.ExecuteReader
            While result.Read
                tabela_dispensa.Rows.Add(result(0), result(5), result(1), result(2), result(3), result(4))
            End While
            Desconectar(conn) ' disconnect from db
        End Sub
        Private Sub Form3_Load(sender As Object, e As EventArgs) Handles MyBase.Load
            BackgroundWorker1.RunWorkerAsync()
            'Conectar(conn, myCommand)
            'myCommand.CommandText = "select dispensa.*,produto.Descrição from dispensa join produto on dispensa.PLU = produto.PLU"
            'result = myCommand.ExecuteReader
            'While result.Read
            '    tabela_dispensa.Rows.Add(result(0), result(5), result(1), result(2), result(3), result(4))
            'End While
            'Desconectar(conn)
        End Sub

        Private Sub BackgroundWorker1_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
            If InvokeRequired Then
                Invoke(New dgvDelegate(AddressOf fill))
            Else
                fill()
            End If
        End Sub
End Class

问题是datagridview只有在加载form3时才会改变。

我已经运行了一些测试，我可以看到，在打开 form3 后，当我收到数据时，datagridview 在我做某事之前会丢失所有行，所以即使丢失数据很奇怪，datagridview 看起来也是一样的。

因此，如果有人可以帮助我更新 datagridview 会很好，但如果有人能帮助我理解为什么 datagridview 会丢失所有数据但显示的内容仍然像什么都没发生，我会很高兴。

重要： Datagridview 没有数据绑定。

如果文字有点乱，请见谅。

Answer 1

在填充数据网格时尝试包括这些（将 DataGridView1 替换为您的任何名称）

        DataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells
        DataGridView1.AutoGenerateColumns = True
        Application.DoEvents()

Answer 2

这个方法对我有用..

Dim command As String
DataGridView1.Columns.Clear()
Dim ds As New DataSet
Try
    Using connection As New SqlConnection(conString)
    command = "Your SQL Query"
    connection.Open()
    Dim da As New SqlDataAdapter(command, connection)
    connection.Close()
    ds.Tables.Add("ProductDetails")
    da.Fill(ds, "ProductDetails")
End Using
DataGridView1.DataSource = ds.Tables("ProductDetails")
DataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells
DataGridView1.AutoGenerateColumns = True
Application.DoEvents()