我已将产品列表从访问数据库检索到 DataGridView。这是代码:
Sub loadProductList()
Try
Using dbConn As New OleDb.OleDbConnection
dbConn.ConnectionString = dbProvider & dbSource
dbConn.Open()
Dim thisSQL As String
thisSQL = "SELECT productID, productName, productCostPrice From " & tblProduct & " WHERE productBrandID=" & CType(txtBrandName.Tag, Integer)
Dim Dadapter As New OleDbDataAdapter(thisSQL, dbConn)
Dim DSet As New DataSet
Dadapter.Fill(DSet, tblProduct)
With DataGridView1
.Columns.Clear()
.DataSource = DSet.Tables(tblProduct)
With .Columns.Item(0)
.Width = 50
.HeaderText = "Code"
.Name = "Code"
End With
Dim txtColumn As New DataGridViewTextBoxColumn
With txtColumn
.Width = 50
.HeaderText = "Qty"
.Name = "Qty"
End With
.Columns.Insert(1, txtColumn)
With .Columns.Item(2)
.Width = 490
.HeaderText = "Description"
End With
With .Columns.Item(3)
.Width = 100
.HeaderText = "Price"
.Name = "Price"
.DefaultCellStyle.Format = "N"
End With
Dim txtaColumn As New DataGridViewTextBoxColumn
.Columns.Insert(4, txtaColumn)
With .Columns.Item(4)
.Name = "Amount"
.HeaderText = "Amount"
.Width = 120
.DefaultCellStyle.Format = "N"
End With
End With
End Using
Catch ex As Exception
End Try
End Sub
Sub UpdatePurchaseItemList()
Try
Using dbConn As New OleDb.OleDbConnection
dbConn.ConnectionString = dbProvider & dbSource
dbConn.Open()
Dim thisSQL As String
thisSQL = "SELECT * FROM " & tblPurchaseItems & " WHERE PitemPID='" & txtRefID.Text & "'"
Using dbDataCmd As New OleDbCommand(thisSQL, dbConn)
Dim dbDataRead As OleDbDataReader
dbDataRead = dbDataCmd.ExecuteReader()
Do While dbDataRead.Read = True
For i As Integer = 0 To DataGridView1.Rows.Count - 1
With DataGridView1.Rows(i)
If .Cells("Code").Value = dbDataRead("PitemProductID") Then
.Cells("Qty").Value = dbDataRead("PitemProductQty")
.Cells("Price").Value = dbDataRead("PitemCost")
.Cells("Amount").Value = dbDataRead("PitemTotal")
Exit For
End If
End With
Next
Loop
End Using
End Using
Catch ex As Exception
End Try
End Sub
在表单加载时,我同时调用 sub:
loadProductList()
UpdatePurchaseItemList() ' 这不会更新任何东西
但是当我在按钮上调用这个子按钮时,它甚至可以完美地工作。
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
UpdatePurchaseItemList() 'it shows the updates.
End Sub
请告诉我为什么它不显示更新?谢谢