Question

我正在尝试将我的进度条一直提升到100％，但它会更新到大约85-95％，然后打开我的下一个表单。有人可以指导我做错了什么吗？我试图编辑步骤和睡眠计数，但我可以设法让它接近进度条的结尾。是否存在一些干扰进度条的代码？

Public Class LoginForm
'
'This specifies the default value for the login attempt
Dim Attempt = 0
Public Function checkinput() As Boolean
    '
    'This is the default username
    Dim Uname = "Niral Mehta"
    '
    'This is the default password
    Dim pword = "Ban4na"
    '
    'This assigns the value of the Username to the UserText.text variable
    Dim Username = UserText.Text
    '
    'This assigns the value of the Password to the PassText.text variable
    Dim Password = PassText.Text
    '
    'Here the Username and password are being assigned the values defined above, if the user input correctly matches the defined values then it returns as true
    If Username = Uname And Password = pword Then
        Return True
    Else
        '
        'If the user fails to put in the correct values on the third attempt then the program automatically shuts down after warning them
        If Attempt = 3 Then
            MsgBox("You have failed to login correctly three times, this program will shut down as a security measure", MsgBoxStyle.OkOnly)
            Me.Close()
            Return False
        End If
        Attempt = Attempt + 1
        MsgBox("Incorrect username and/or password", MsgBoxStyle.OkOnly)
        Return False
    End If
End Function

Private Sub KillProcess_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles KillProcess.Click
    '
    'When the end program button is clicked, a message box will pop up and give the options to end the program
    If MsgBox("Are you sure you want to quit?", MsgBoxStyle.YesNo) = DialogResult.Yes Then
        Me.Close()
    End If
End Sub

Private Sub PassText_TextChanged(sender As Object, e As EventArgs) Handles PassText.TextChanged
    '
    'This hides the password characters 
    PassText.PasswordChar = "#"

    'This sets the character length for a password 
    '
    PassText.MaxLength = 8
End Sub

Private Sub UserText_TextChanged(sender As Object, e As EventArgs) Handles UserText.TextChanged
    '
    'This sets the character length for a username
    UserText.MaxLength = 14
End Sub

Private Sub StartNextForm_Click(sender As Object, e As EventArgs) Handles StartNextForm.Click
    If checkinput() Then
        With LoginProgress
            .Visible = True
            .Step = 2
            .Maximum = 101
            .Style = ProgressBarStyle.Blocks
            .Value = 0
        End With
        Do
            System.Threading.Thread.Sleep(100)
            LoginProgress.PerformStep()
        Loop Until LoginProgress.Value >= LoginProgress.Maximum
        FrmMain.Show()
        Me.Hide()
    End If
End Sub

Answer 1

使用计时器可以使用以下代码：

计时器代码：

Private Sub Timer_Tick(sender As Object, e As EventArgs) Handles Timer.Tick
    If prgStatus.Value = prgStatus.Maximum Then
        Timer.Enabled = False
        prgStatus.Value = 0
        Exit Sub
    End If
    prgStatus.Value = prgStatus.Value + 1
    If (prgStatus.Value = 1) Then
        'Do something
    End If
End Sub

注意：“做某事”的所有代码都必须在

之下

prgStatus.Value = prgStatus.Value + 1

启动计时器，只需将此代码放在一个按钮，表单加载等

Timer.Enabled = True

你可以多少

        If (prgStatus.Value = 1) Then
        'Do something
    End If

如你所愿。

要延迟它，只需更改进度条的最大值或更改计时器滴答。

希望有所帮助：）

Answer 2

您的事件未被处理，因为您正在运行（占用）您的UI线程的循环，并且没有在任何时候处理事件时提供UI线程消息泵

尝试添加Application.DoEvents()

Do    
    System.Threading.Thread.Sleep(100)
    LoginProgress.PerformStep()
    Application.DoEvents() ' <-- this
Loop Until LoginProgress.Value >= LoginProgress.Maximum

Visual Studio 2012 - 进度条

2 个答案: