将数据集/表绑定到 DataGridView

Question

我目前正在编写一个链接到数据库的简单库存控制 Visual Basic 程序。

Here's what it looks like so far.

表单在 DataGrid 视图中显示数据，我正在尝试在我正在使用的数据库中更改数据（使用 SQL）时自动刷新我的 DataGridView。

在做了一些研究后，我发现最好的方法是将数据表（使用 BindingSource）绑定到 DataGridView

但是我正在努力实现这一点，因为我尝试过的每个实现都会导致一个空白的 DataGridView，如果有人可以帮助我，我将不胜感激。

代码如下：

Imports System.Data.OleDb

Public Class Form1
Public connectionString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=dbStock.accdb"
Public conn As New OleDb.OleDbConnection(connectionString)

Public Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    Me.TblStockControlTableAdapter.Fill(Me.DbStockDataSet.tblStockControl)

    For i As Integer = 1 To 5
        ComboBoxQty1.Items.Add(i)
        ComboBoxQty2.Items.Add(i)
    Next

    Dim SqlQuery As String = "Select tblStockControl.[EggType] FROM tblStockControl"
    Dim da As OleDbDataAdapter = New OleDbDataAdapter(SqlQuery, conn)
    Dim ds As DataSet = New DataSet
    da.Fill(ds, "tblStockControl")
    Dim dt As DataTable = ds.Tables("tblStockControl")
    'DataGridView1.DataSource = dt

    For Each row As DataRow In dt.Rows
        ComboBoxAdd.Items.Add(row.Item(0))
    Next

    For Each row As DataRow In dt.Rows
        ComboBoxTake.Items.Add(row.Item(0))
    Next

End Sub

Private Sub btnAddEgg_Click(sender As Object, e As EventArgs) Handles btnAddEgg.Click

    conn.Open()

    Dim SqlQuery As String = "Select tblStockControl.[Quantity] FROM tblStockControl WHERE EggType = '" & ComboBoxAdd.Text & "'"

    Dim da As OleDbDataAdapter = New OleDbDataAdapter(SqlQuery, conn)
    Dim ds As DataSet = New DataSet
    da.Fill(ds, "tblStockControl")
    Dim dt As DataTable = ds.Tables("tblStockControl")

    Dim qty As Integer = 0

    For Each row As DataRow In dt.Rows
        For Each column As DataColumn In dt.Columns
            qty = row(column)
        Next
    Next

    Dim NewQty As Integer = qty + CInt(ComboBoxQty2.Text)

    UpdateAddQty(NewQty)

    conn.Close()

End Sub

Function UpdateAddQty(ByRef NewQty As Integer) As Integer
    Dim SqlUpdate As String = "UPDATE tblStockControl SET Quantity = '" & NewQty & "' WHERE EggType = '" & ComboBoxAdd.Text & "'"

    Dim SqlCommand As New OleDbCommand
    With SqlCommand
        .CommandText = SqlUpdate
        .Connection = conn
        .ExecuteNonQuery()
    End With

    Return (Nothing)
End Function

Private Sub btnViewStock_Click(sender As Object, e As EventArgs) Handles btnViewStock.Click
    'Add code to open Access file.
End Sub

Private Sub btnTakeEgg_Click(sender As Object, e As EventArgs) Handles btnTakeEgg.Click
    conn.Open()

    Dim SqlQuery As String = "Select tblStockControl.[Quantity] FROM tblStockControl WHERE EggType = '" & ComboBoxTake.Text & "'"

    Dim da As OleDbDataAdapter = New OleDbDataAdapter(SqlQuery, conn)
    Dim ds As DataSet = New DataSet
    da.Fill(ds, "tblStockControl")
    Dim dt As DataTable = ds.Tables("tblStockControl")

    Dim qty As Integer = 0

    For Each row As DataRow In dt.Rows
        For Each column As DataColumn In dt.Columns
            qty = row(column)
        Next
    Next

    Dim NewQty As Integer = CInt(ComboBoxQty1.Text) - qty

    UpdateTakeQty(NewQty)

    conn.Close()
End Sub

Function UpdateTakeQty(ByRef NewQty As Integer) As Integer
    Dim SqlUpdate As String = "UPDATE tblStockControl SET Quantity = '" & NewQty & "' WHERE EggType = '" & ComboBoxTake.Text & "'"

    Dim SqlCommand As New OleDbCommand
    With SqlCommand
        .CommandText = SqlUpdate
        .Connection = conn
        .ExecuteNonQuery()
    End With

    Return (Nothing)
End Function

结束类

Answer 1

如果您使用的是 DataTable ，则重置 DataGridView 的数据源。我的意思是您需要再次从数据库中读取数据。 ：

'Do this every time you add/Update a data
Dim da As OleDbDataAdapter = New OleDbDataAdapter(SqlQuery, conn)
Dim ds As DataSet = New DataSet
da.Fill(ds, "tblStockControl")
Dim dt As DataTable = ds.Tables("tblStockControl")

或者您可以为添加到数据库的每个数据创建一行：

 'Do this every time you add a data
 DataGridViewRow row = (DataGridViewRow)DataGridView1.Rows[0].Clone()
 row.Cells[0].Value = "Alex"
 row.Cells[1].Value = "Jordan"
 DataGridView1.Rows.Add(row)