VB2005 禁止控件自动刷新问题

[oo渣渣oo]

=== 现状:

我的项目中做了一个加载数据行的窗口,用ListView显示数据,此窗口暂且称为Form1.

由于数据比较多,大概有2000多行,我就用了另一个窗口带ProgressBar的方式还显示加载的进度,此窗口暂且称为Form2.

同时时,为了让ProgressBar窗口(Form2)正常显示,我在Form1的加载循环中用了Application.DoEvents()来释放CPU占用.

=== 问题:
Application.DoEvents()用了以后,加载数据明显变慢了,加载时间是不用Application.DoEvents()的几倍!

我判断是因为ListView在不断地重绘导致消耗了过多的CPU时钟.

=== 尝试过的方法:
1. 用SuspendLayout()和ResumeLayout()想停止控件刷新,未果.
2. 用Visible = False的方式倒是不错,加载速度明显恢复了,但是界面太难看....

=== 求解:
有没有高级点的方式,来实现以下目的?

1.不要隐藏ListView控件,加载数据过程中Form1或ListView不刷新,直至加载完毕后一次性显示.

2.同时又要保证ProgressBar窗口(Form2)能正常刷新.

[古今多少事]

那你用两个ListView，一个用来显示，真正加载数据的隐藏，加载完再显示。

[水哥阿乐]

学习，帮顶

[skep99]

数据库加载到容器后再绑定 ListView
ListView用虚模式显示
2000行也就一眨眼,根本用不着ProgressBar来显示

[sxmonsy]

每天回帖即可获得10分可用分！

[足球中国]

Application.DoEvents()的意思楼主要看一下。
这个是vb那引过来的。
是把操作权交给系统。交给系统意味着。你的程序所分配的各种资源会重新分配。这样会导致你的程序变慢。
你可以用线程来处理这个东东。

[ncqingchuan1976]

两个窗体
form1 控件datagridview:datagridview1 ,button:OKbtn
form2 控件ProcessBar:PB
通过异步调用实现楼主的方法,且FORM2窗体不会出现未响应，代码如下:

Imports System.ComponentModel

Public Class Form1
    Private m_Count As Integer '

    Dim PrcentForm As Form2

    Private Delegate Sub PrecentChangeDelegate(ByVal Precent As Integer)
    Private Delegate Sub RunDelegate()
    Private Delegate Sub CompleteDelegate()

    Private Asyresult As IAsyncResult
    Private List As BindingList(Of Datalist)

    Private Run As RunDelegate
    Public Sub DisPlayPrecent(ByVal Precent As Integer)
        PrcentForm.PB.Value = Precent
        If Precent = 100 Then
            PrcentForm.Close()
        End If
    End Sub

    Private Sub OKbtn_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles OKbtn.Click

        m_Count = 40000
        PrcentForm = Form2
        PrcentForm.Show()


        Run = New RunDelegate(AddressOf LoadData)  '异步调用数据加载过程
        Asyresult = Run.BeginInvoke(New AsyncCallback(AddressOf CallBack), Nothing)

    End Sub

    Private Sub CallBack()  '通过回调实现绑定
        Run.EndInvoke(Asyresult)
        Me.Invoke(New CompleteDelegate(AddressOf BindingData))

    End Sub

    Private Sub BindingData()   '绑定到DataGridView1
        Me.DataGridView1.DataSource = List
    End Sub

    Private Sub LoadData() '模拟加载数据
        List = New BindingList(Of Datalist)
        List.Clear()
        Dim i As Integer = 0
        While i <= m_Count
            Dim T As New Datalist(i)
            Me.Invoke(New PrecentChangeDelegate(AddressOf DisPlayPrecent), New Object() {CInt(i / m_Count * 100)})
            List.Add(T)
            i += 1
        End While
    End Sub
End Class


Public Class Datalist  '数据模型
    Private m_Number As Integer
    Public ReadOnly Property Number()
        Get
            Return m_Number
        End Get
    End Property
    Public Sub New(ByVal I As Integer)
        m_Number = I
    End Sub

End Class

[ncqingchuan1976]

采取异步方式
以下须一个button,processbar

Public Class Form3
    Private Delegate Function DisPlayText(ByVal Intput As Long)

    Private Delegate Sub DisValue(ByVal Value As Integer)

    Private exv As Boolean

    Private Sub PbValue(ByVal Value As Integer)
        PB.Value = Value
    End Sub
    Private Sub metext(ByVal text As Long)
        Me.Text = text.ToString
    End Sub
    Dim iresult As IAsyncResult
    Dim A As DisPlayText
    Private Function Cal(ByVal Intput As Long) As Integer
        Dim i As Long
        Dim t As Long
        For i = 0 To Intput
            t = i + 1
            Me.Invoke(New DisValue(AddressOf PbValue), CInt((i / Intput) * 100))
        Next
        Return t
    End Function
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        If Not exv Then

            Try
                A = New DisPlayText(AddressOf Cal)
                iresult = A.BeginInvoke(100000, New AsyncCallback(AddressOf CallBack), Nothing)
            Catch ex As Exception

            Finally
                exv = True
            End Try

        End If

    End Sub

    Private Sub CallBack()

        Try
            Dim i As Integer = A.EndInvoke(iresult)
            Me.Invoke(New DisValue(AddressOf metext), i)
        Catch ex As Exception

        Finally

            exv = False
        End Try

    End Sub

End Class

[ncqingchuan1976]

两个窗体form1,form2 form1上有控件button 名OKBtn,listview名LV。form2上有processbar 名PB
form1代码

Public Class Form1
    Private m_Count As Integer
    Dim PrcentForm As Form2
    Private Delegate Sub PrcentChangeDelegate(ByVal Prcent As Integer)

    Public ReadOnly Property Count() As Integer
        Get
            Return m_Count
        End Get
    End Property
    Private Sub OKbtn_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles OKbtn.Click
        LV.Items.Clear()
        PrcentForm = Form2
        PrcentForm.Show()

        Dim i As Integer = 0
        While i <= m_Count  '模拟加载数据
            PrcentForm.Invoke(New PrcentChangeDelegate(AddressOf PrcentForm.DisPlayVal), New Object() {CInt((i / (m_Count)) * 100)})
            LV.Items.Add(i)
            LV.Items(i).SubItems.Add(i)
            i += 1
        End While
        PrcentForm.Close()

    End Sub

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        LV.Columns.Add("数据", 200, HorizontalAlignment.Center)
        m_Count = 10000
        Control.CheckForIllegalCrossThreadCalls = False
    End Sub

End Class

form2代码

Public Sub DisPlayVal(ByVal Prcent As Integer)
        PB.Value = Prcent

    End Sub

不知是否是你要的效果.

[messi_yang]

來學習哈····

[1dit]

请参考：
http://www.microsoft.com/china/msdn/library/architecture/architecture/architecturetopic/SCArchDeGuide/Chapter8SCAppPerf.mspx?mfr=true

[Forrest23]

以前也做过一个 用另外一个窗体来显示进度条的窗体
’写了个函数 主要代码如下

            If Number = 0 Then
            frmProgress.Show()
            frmProgress.prgbar.Value = Number
            frmProgress.Label1.Text = str_caption
        ElseIf Number = 100 Then
            frmProgress.prgbar.Value = Number
            frmProgress.Label1.Text = str_caption
            frmProgress.Close()
            frmProgress.Dispose()
        Else
            frmProgress.prgbar.Value = Number
            frmProgress.Label1.Text = str_caption
        End If
        frmProgress.Refresh()
'这样可以进度条窗体可以正常显示 并不需要加 Application.DoEvents()

[oo渣渣oo]

问题已解决,把所有数据先丢到ListViewItem的数组中,最后再添加到控件内.

虽然大家的意见没用上,不过辛苦费还是有滴,分脏........

[皇城龙三]

取出来先赋值给一个数组，再填充listview

[oo渣渣oo]

哇,好多回答,慢慢研究中..........

[Forrest23]

怎么还没分脏？

[oo渣渣oo]

不好意思,搞忘记了......现在就分!