Question

我一直在尝试处理表单上的控件的Paint事件。然而事件永远不会被处理，我不确定我做错了什么。我已经创建了一个非常简单的WinForms项目来演示这个（我已经包含了生成的设计器代码，以表明那里没有其他内容）：

Form1.vb的

Public Class Form1
    Private Sub Form1_Load( sender As Object,  e As EventArgs) Handles MyBase.Load
        AddHandler VScrollBar1.Paint, AddressOf VScrollBar1_Paint
    End Sub

    Private Sub VScrollBar1_Paint (ByVal sender As Object, ByVal e As PaintEventArgs)
        Dim str As String = "test"
        System.Windows.Forms.MessageBox.Show(str)
    End Sub                              
End Class

Form1.Designer.vb

<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()> _
Partial Class Form1
    Inherits System.Windows.Forms.Form

    'Form overrides dispose to clean up the component list.
    <System.Diagnostics.DebuggerNonUserCode()> _
    Protected Overrides Sub Dispose(ByVal disposing As Boolean)
        Try
            If disposing AndAlso components IsNot Nothing Then
                components.Dispose()
            End If
        Finally
            MyBase.Dispose(disposing)
        End Try
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    <System.Diagnostics.DebuggerStepThrough()> _
    Private Sub InitializeComponent()
        Me.VScrollBar1 = New System.Windows.Forms.VScrollBar()
        Me.SuspendLayout
        '
        'VScrollBar1
        '
        Me.VScrollBar1.Location = New System.Drawing.Point(26, 56)
        Me.VScrollBar1.Name = "VScrollBar1"
        Me.VScrollBar1.Size = New System.Drawing.Size(17, 80)
        Me.VScrollBar1.TabIndex = 0
        '
        'Form1
        '
        Me.AutoScaleDimensions = New System.Drawing.SizeF(6!, 13!)
        Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
        Me.ClientSize = New System.Drawing.Size(284, 261)
        Me.Controls.Add(Me.VScrollBar1)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(false)

    End Sub
        Friend WithEvents VScrollBar1 As System.Windows.Forms.VScrollBar

End Class

永远不会处理事件，但会正确绘制控件。我错过了什么？

Answer 1

好吧，在花了一点时间之后，我发现您需要做的只是调用SetStyle()方法，并将flag和value参数设置为ControlStyles.userPaint和{分别为{1}}。

这种方法不公开，因此需要反思才能调用它：

True

我将上面的代码放在上面的Form1_Load方法中，就在Dim methodInfo As System.Reflection.MethodInfo = VScrollBar1.GetType().GetMethod("SetStyle", Reflection.BindingFlags.Instance Or Reflection.BindingFlags.NonPublic) methodInfo.Invoke(VScrollBar1, {ControlStyles.UserPaint, True})行的上方，它似乎可以工作（我可以处理事件）。

处理VScrollbar Paint事件

1 个答案: