如何將事件添加到通過單擊按鈕 VB.NET 動態創建的 PictureBox

Question

使用文本框添加我動態創建的數字，例如表單中的 5 個圖片框，如下所示：

Sub CreateImages()
    Dim pb As New PictureBox
    Dim i As Integer = TextBoxNumberImages.Text
    Dim Z As Integer = 10

    pb.Top = 50
    pb.Left = 50
    pb.Tag = Color.Black
    pb.BackColor = Color.Red

    For i = 1 To i
        pb = New PictureBox
        pb.Width = 120
        pb.Height = 330
        pb.Left += Z
        pb.Tag = False
        pb.Name = "Image" + Str(i)
        pb.BorderStyle = BorderStyle.FixedSingle

        pb.BackColor = Color.Green
        AddHandler pb.Click, AddressOf _Click

        Me.Controls.Add(pb)
        pb.Refresh()
        Z += 125
    Next
End Sub

然后，在創建圖片框后，單擊每個..使用AddHandler pb.Click, AddressOf _Click我得到焦點和 3 個按鈕來處理當前圖片框（只需增加/減少或剪切成兩部分），使用以下代碼：

Public Sub _Click(ByVal sender As Object, ByVal e As EventArgs)
    Dim pb As PictureBox = DirectCast(sender, PictureBox)
    Dim selected As Boolean = DirectCast(pb.Tag, Boolean)

         
    Dim d As Integer
    For d = 1 To TextBoxNumberImages.Text
        If pb.Name = "Image" + Str(d) Then
            NOMEPIC = pb.Name
            pb.BackColor = Color.Blue
            '   MsgBox(pb.Location.X & "X")
            '   MsgBox(pb.Location.Y & "Y")
            BtnAdd.Top = pb.Location.Y + 330
            BtnAdd.Left = pb.Location.X
            BtnSub.Top = pb.Location.Y + 330
            BtnSub.Left = pb.Location.X + 40
            BtnNew.Top = pb.Location.Y + 330
            BtnNew.Left = pb.Location.X + 80
            Label1.Top = pb.Location.Y + 360
            Label1.Left = pb.Location.X
            Label1.Text = "Art. " & d
            txtArt.Top = pb.Location.Y + 380
            txtArt.Left = pb.Location.X
        End If
    Next
    BtnAdd.Visible = True
    BtnSub.Visible = True
    BtnNew.Visible = True
    Label1.Visible = True
    txtArt.Visible = True
    pb.Refresh()

現在我想通過 3 個按鈕來管理它們（“+”增大尺寸“-”減小尺寸 e cut...）但我不知道如何讓圖片框聚焦（參與）。

Answer 1

只需保留對上次單擊的 PictureBox 的引用，然后在按鈕處理程序中對其進行操作

Private selectedPictureBox As PictureBox

Private Sub _Click(sender As Object, e As EventArgs)
    selectedPictureBox = DirectCast(sender, PictureBox)
    ' ...
End Sub

Private Sub btnAdd_Click(sender As Object, e As EventArgs) Handles btnAdd.Click
    If selectedPictureBox Is Nothing Then Exit Sub
    selectedPictureBox.Width += 1
    selectedPictureBox.Height += 1
End Sub

Private Sub btnSub_Click(sender As Object, e As EventArgs) Handles btnSub.Click
    If selectedPictureBox Is Nothing Then Exit Sub
    selectedPictureBox.Width -= 1
    selectedPictureBox.Height -= 1
End Sub