Question

程序启动。当我单击“开始”按钮时，原始表单会像我预期的那样消失，但之后它就会挂起。没有图片显示。 CPU加热并变大。它冻结，我有时必须按CTRL + ALT + DELETE退出程序。

'Reaction.exe

'Picture comes up once, user presses left side of keyboard (Q,A,or Z)  
'Picture comes up a second time, user presses right side of keyboard (P,L,or M)
'A total of 10 .bmps, pictures show up randomly, a picture will only show up twice 
'Time (in millisecods) is recorded for each attempt 
'If user presses correct key, 
'For example if user presses 2 and it is the 2nd time the picture has shown up 
'Accuracy goes up a point (maximum of 10) 
'If user presses wrong key,  
'For example if user presses 2 even though the picture has only shown up once 
'Accuracy goes down a point (minimum of 0)


Public Class Form_Main


'Declare Globals'
Public X As Integer = 0 'Used in DisplayImage() function
Public I As Integer = 0 'Used for Times array and CalcTime() function
Public Num As Integer = 0   'Used in branches
Public Flag As Integer = 0
Public Accuracy As Integer = 0
Public Speed As Double = 0
Public Delay As Integer = 0
Public Timer_Start As Double = 0
Public Timer_End As Double = 0

'Arrays
'Times Array
Public Times(20) As Double  'Holds 20 times (since each picture will pop up twice)'

'Main Array
'Field = How many images will be used (Default is 10, for 10 pictures)
'Value:
'0 = Picture hasn't been used yet
'1 = Picutre has been used
'2 = Picture has already been used twice, and will not appear again
Dim MainArray(10) As Integer


' Start Button click (Main Function)
Private Sub Button_Start_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_Start.Click
    ' Disable and hide the form
    RadioButton_Images.Visible = False
    RadioButton_Inkblots.Visible = False
    RadioButton_Words.Visible = False
    Button_Start.Visible = False
    Button_Reset.Visible = False
    RadioButton_Images.Enabled = False
    RadioButton_Inkblots.Enabled = False
    RadioButton_Words.Enabled = False
    Button_Start.Enabled = False
    Button_Reset.Enabled = False

    'Images branch
    If RadioButton_Images.Checked Then
        Images()
    End If

    'Show the Reset Button
    Button_Reset.Visible = True
    Button_Reset.Enabled = True
End Sub


'Functions
'Images() Function
Private Function Images() As Action
    Do Until (Num = 10)
        Timer_Start = 0
        Timer_End = 0
        Flag = 0
        Delay = Rand(3000, 6000)
        System.Threading.Thread.Sleep(Delay) '3-6 second delay
        DisplayImage()
        Timer_Start = TimeOfDay.Millisecond
        Do While (Flag = 0)
        Loop
        CalcTime()
    Loop
End Function


'Rand() Function (returns a random integer between (x,y) )
Private Function Rand(ByVal Low As Long, ByVal High As Long) As Long
    'randomize function
    Randomize()
    Rand = Int((High - Low + 1) * Rnd()) + Low
End Function


'DisplayImage() Function
Private Function DisplayImage() As Action
    Do Until PictureBox.Visible = True
        X = Rand(1, 10)  'Get a random number from 1 to 10

        Select Case X
            Case Is = 1
                If MainArray(X) = 0 Then                    'First time the picture is used
                    PictureBox.ImageLocation = "C:\Reaction\Images\1.bmp"
                    MainArray(X) = 1
                    PictureBox.Visible = True
                ElseIf MainArray(X) = 1 Then                'Second time the picture is up
                    PictureBox.ImageLocation = "C:\Reaction\Images\1.bmp"
                    MainArray(X) = 2
                    Num = Num + 1
                    PictureBox.Visible = True
                Else                                        'If MainArray(X) doesn't = 1 or 0
                End If                                      'Then endif and get another rand #
            Case Is = 2
                If MainArray(X) = 0 Then
                    PictureBox.ImageLocation = "C:\Reaction\Images\2.bmp"
                    MainArray(X) = 1
                    PictureBox.Visible = True
                ElseIf MainArray(X) = 1 Then
                    PictureBox.ImageLocation = "C:\Reaction\Images\2.bmp"
                    MainArray(X) = 2
                    Num = Num + 1
                    PictureBox.Visible = True
                Else
                End If
            Case Is = 3
                If MainArray(X) = 0 Then
                    PictureBox.ImageLocation = "C:\Reaction\Images\3.bmp"
                    MainArray(X) = 1
                    PictureBox.Visible = True
                ElseIf MainArray(X) = 1 Then
                    PictureBox.ImageLocation = "C:\Reaction\Images\3.bmp"
                    MainArray(X) = 2
                    Num = Num + 1
                    PictureBox.Visible = True
                Else
                End If
                ...
        End Select
    Loop
End Function


Private Function CalcTime() As Action
    'Calculates the time in milliseconds
    'Records to Times() array
    Times(I) = Timer_Start - Timer_End
    I = I + 1
End Function


Private Sub Form_Main_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles MyBase.KeyPress

    'Keypress Q, A, or Z if the picture is seen for the first time
    'Otherwise one accuracy point is deducted
    If e.KeyChar = "Q" Or "A" Or "Z" Or "q" Or "a" Or "z" Then
        If PictureBox.Visible = True Then
            If MainArray(X) = 1 Then
                Timer_End = TimeOfDay.Millisecond
                PictureBox.Image = Nothing
                PictureBox.Visible = False
                Accuracy = Accuracy + 1
                Flag = 1
            Else
                Timer_End = TimeOfDay.Millisecond
                PictureBox.Image = Nothing
                PictureBox.Visible = False
                Accuracy = Accuracy - 1
                Flag = 1
            End If
        End If
    End If

    'Keypress for second occurance
    If e.KeyChar = "P" Or "L" Or "M" Or "p" Or "l" Or "m" Then
        If PictureBox.Visible = True Then
            If MainArray(X) = 2 Then
                Timer_End = TimeOfDay.Millisecond
                PictureBox.Image = Nothing
                PictureBox.Visible = False
                Accuracy = Accuracy + 1
                Flag = 1
            Else
                Timer_End = TimeOfDay.Millisecond
                PictureBox.Image = Nothing
                PictureBox.Visible = False
                Accuracy = Accuracy - 1
                Flag = 1
            End If
        End If
    End If
End Sub



'Reset button
Private Sub Button_Reset_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_Reset.Click
    'Reset all global variables
    X = 0
    I = 0
    Num = 0
    Flag = 0
    Accuracy = 0
    Speed = 0
    Delay = 0
    Timer_Start = 0
    Timer_End = 0
    'temporarily use I and X to clear out MainArray() and Times() array
    For I = 0 To I = 10
        MainArray(I) = 0
    Next

    For X = 0 To X = 20
        Times(X) = 0
    Next
    'Reset back to 0
    X = 0
    I = 0

    'Enable and show the form, hiding the reset button
    RadioButton_Images.Visible = True
    RadioButton_Inkblots.Visible = True
    RadioButton_Words.Visible = True
    Button_Start.Visible = True
    Button_Reset.Visible = False
    RadioButton_Images.Enabled = True
    RadioButton_Inkblots.Enabled = True
    RadioButton_Words.Enabled = True
    Button_Start.Enabled = True
    Button_Reset.Enabled = False
End Sub

End Class

Answer 1

没有经过所有代码，我认为以下片段是主要问题：

Do While (Flag = 0)
Loop

我注意到你正在设置Flag以对某些KeyPress事件作出进一步的反应，为了完成这项工作，你必须至少改变循环

Do While (Flag = 0)
  Application.DoEvents
Loop

但我强烈建议重新设计不需要这么繁忙的循环

Answer 2

你有一对Do While循环（Do Until（Num = 10），Do While（Flag = 0））永远不会停止，所以当程序击中它们时它会进入永无止境的“无限循环” ”

您写道：

   Do While (Flag = 0)
   Loop

...但是你需要在这两行之间使用一些代码来将Flag的值更改为0以外的其他值，否则计算机无法满足条件，并且它将永远无法循环。例如此假设的示例将等待用户按Esc键：

   Do While (Flag = 0)
       If UserPressedEscape() Then Flag = 1
   Loop

CPU加热，冷却风扇全速运转，因为程序使用100％CPU时间疯狂循环。

（我想你希望程序中的事件处理代码在你的循环运行时“在后台”执行，但实际上计算机一次只做一件事，所以它永远不会退出循环能够运行你的事件处理程序。如果程序是“多线程的”那么这是可能的，但它的编写方式，它是“单线程”，所以程序只是按顺序一次完成一件事，所以它永远不会脱离循环）

图像不显示 - 程序冻结

2 个答案: