作为一个相当新的VB.NET用户,我很困惑为什么当我在form_load上调用sub时DataGridView没有填充。我一直在玩这个和google搜索一段时间,但仍然没有快乐。我知道这是我的错误,还没有足够的调试知道到底要找什么。我在form_load事件的frmMain中使用' DGVmod.fillPostings()来调用sub。代码在模块中。这有什么区别吗?有人可以告诉我我的基本错误。非常感谢
Imports System
Imports System.Data
Imports System.Data.OleDb
Module DGVmod
Private da As OleDbDataAdapter
Private ds As DataSet
Private dtSource As DataTable
Private PageCount As Integer
Private maxRec As Integer
Private pageSize As Integer
Private currentPage As Integer
Private recNo As Integer
Sub fillPostings()
Dim conn As OleDbConnection = New OleDbConnection(My.Settings.storageConnectionString)
'Set the DataAdapter's query.
da = New OleDbDataAdapter("select * from Postings", conn)
ds = New DataSet()
' Fill the DataSet.
da.FillSchema(ds, SchemaType.Source, "Postings")
da.Fill(ds, "Postings")
' Set the source table.
dtSource = ds.Tables("Postings")
End Sub
Sub btnprevious()
If Not CheckFillButton() Then Return
If currentPage = PageCount Then
recNo = pageSize * (currentPage - 2)
End If
currentPage = currentPage - 1
'Check if you are already at the first page.
If currentPage < 1 Then
MessageBox.Show("You are at the First Page!")
currentPage = 1
Return
Else
recNo = pageSize * (currentPage - 1)
End If
fillPostings()
loadpages()
End Sub
Sub btnnext()
'If the user did not click the "Fill Grid" button then Return
If Not CheckFillButton() Then Return
'Check if the user clicked the "Fill Grid" button.
If pageSize = 0 Then
MessageBox.Show("Set the Page Size, and then click the ""Fill Grid"" button!")
Return
End If
currentPage = currentPage + 1
If currentPage > PageCount Then
currentPage = PageCount
'Check if you are already at the last page.
If recNo = maxRec Then
MessageBox.Show("You are at the Last Page!")
Return
End If
End If
fillPostings()
loadpages()
End Sub
Sub btnlast()
If Not CheckFillButton() Then Return
' Check if you are already at the last page.
If recNo = maxRec Then
MessageBox.Show("You are at the Last Page!")
Return
End If
currentPage = PageCount
recNo = pageSize * (currentPage - 1)
fillPostings()
loadpages()
End Sub
Private Sub DisplayPageInfo()
frmMain.txtDisplayPageNo.Text = "Page " & currentPage.ToString & "/ " & PageCount.ToString
End Sub
Sub fillgrid()
Try
'Set the start and max records.
pageSize = CInt(frmMain.cmbPageSize.Text)
maxRec = frmMain.DGV.Rows.Count
PageCount = maxRec \ pageSize
' Adjust the page number if the last page contains a partial page.
If (maxRec Mod pageSize) > 0 Then
PageCount = PageCount + 1
End If
'Initial seeings
currentPage = 1
recNo = 0
' Display the content of the current page.
fillPostings()
loadpages()
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
Private Sub loadpages()
Dim i As Integer
Dim startRec As Integer
Dim endRec As Integer
Dim dtTemp As DataTable
'Dim dr As DataRow
'Duplicate or clone the source table to create the temporary table.
dtTemp = dtSource.Clone
If currentPage = PageCount Then
endRec = maxRec
Else
endRec = pageSize * currentPage
End If
startRec = recNo
'Copy the rows from the source table to fill the temporary table.
For i = startRec To endRec - 1
dtTemp.ImportRow(dtSource.Rows(i))
recNo = recNo + 1
Next
frmMain.DGV.DataSource = dtTemp
DisplayPageInfo()
'fillPostings()
End Sub
Sub btnfirst()
If Not CheckFillButton() Then Return
' Check if you are already at the first page.
If currentPage = 1 Then
MessageBox.Show("You are at the First Page!")
Return
End If
currentPage = 1
recNo = 0
fillPostings()
loadpages()
End Sub
Private Function CheckFillButton() As Boolean
'Check if the user clicks the "Fill Grid" button.
If pageSize = 0 Then
MessageBox.Show("Set the Page Size, and then click the ""Fill Grid"" button!")
CheckFillButton = False
Else
CheckFillButton = True
End If
End Function
Sub cmbpage()
'Set the start and max records.
pageSize = CInt(frmMain.cmbPageSize.Text)
maxRec = dtSource.Rows.Count
PageCount = maxRec \ pageSize
' Adjust the page number if the last page contains a partial page.
If (maxRec Mod pageSize) > 0 Then
PageCount = PageCount + 1
End If
'Initial seeings
currentPage = 1
recNo = 0
' Display the content of the current page.
fillPostings()
loadpages()
End Sub
End Module
frmMain加载代码
Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'StorageDataSet1.Customers' table. You can move, or remove it, as needed.
Me.CustomersTableAdapter.Fill(Me.StorageDataSet1.Customers)
'TODO: This line of code loads data into the 'StorageDataSet.User' table. You can move, or remove it, as needed.
Me.UserTableAdapter.Fill(Me.StorageDataSet.User)
lblDate.Text = CStr(Now)
Timer1.Start()
rdoCustomer.Enabled = False
rdoCustomer.Checked = True
rdoDepartment.Enabled = False
rdoDepartment.Checked = False
For Each ctrl In pnlContainer.Controls
If TypeOf ctrl Is Button Then
AddHandler CType(ctrl, Button).MouseDown, AddressOf btn_MouseDown
End If
Next
DGVmod.fillPostings()
End Sub
答案 0 :(得分:1)
在fillpostings
功能上:
' Set the source table.
dtSource = ds.Tables("Postings")
Me.DataGridView1.DataSource = dtSource