VB2005 禁止控件自动刷新问题

oo渣渣oo 2010-05-21 05:31:44

=== 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.

...全文

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oo渣渣oo 2010-05-26

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不好意思,搞忘记了......现在就分!

Forrest23 2010-05-25

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怎么还没分脏？

oo渣渣oo 2010-05-24

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哇,好多回答,慢慢研究中..........

皇城龙三 2010-05-24

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取出来先赋值给一个数组，再填充listview

oo渣渣oo 2010-05-24

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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........

Forrest23 2010-05-22

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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()

1dit 2010-05-22

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

messi_yang 2010-05-22

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來學習哈····

ncqingchuan1976 2010-05-22

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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.

ncqingchuan1976 2010-05-22

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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 2010-05-22

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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