在 vb.net 中通过拖放在图片框上进行交换子

Question

我想制作一个可以应用于我的动态子组件，我有一个带有图片框的 3x3 矩阵，我想用拖放样式更改它们中的图像。

我找到了这段代码，我知道它是如何工作的，但我想让它动态化，这样它就可以在表单中的所有 9 个 picbox 上工作，而不仅仅是前两个。

Dim firstimage As Image
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    PictureBox2.AllowDrop = True
End Sub
Private Sub pictureBox1_MouseMove(ByVal sender As Object, ByVal e As MouseEventArgs) Handles PictureBox1.MouseMove
    If e.Button = MouseButtons.Left Then
        PictureBox1.DoDragDrop(PictureBox1.Image, DragDropEffects.All)
    End If
End Sub
Private Sub pictureBox2_DragEnter(ByVal sender As Object, ByVal e As DragEventArgs) Handles PictureBox2.DragEnter
    firstimage = PictureBox2.Image
    If e.Data.GetDataPresent(DataFormats.Bitmap) Then
        e.Effect = DragDropEffects.Copy
    Else
        e.Effect = DragDropEffects.None
    End If
End Sub
Private Sub pictureBox2_DragDrop(ByVal sender As Object, ByVal e As DragEventArgs) Handles PictureBox2.DragDrop
    If (e.Data.GetDataPresent(DataFormats.Bitmap)) Then
        PictureBox2.Image = CType((e.Data.GetData(DataFormats.Bitmap)), Bitmap)
        PictureBox1.Image = firstimage 'Set picturebox1 to the stored image
    End If
End Sub

我已经阅读并使用了 idle_mind 答案，它的工作非常好，这正是我想要的，但我需要再更新一次才能让它为我工作。 我不仅需要更改图像，还需要更改框的标签（像图像一样交换它们。） 我在这里所做的是只有第一个得到标签，但第二个你不能解释我需要在哪里添加代码更改。

Private Sub PBs_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
        Dim PB As PictureBox = DirectCast(sender, PictureBox)
        If Not IsNothing(PB.Image) AndAlso e.Button = Windows.Forms.MouseButtons.Left Then
            Source = PB
            PB.DoDragDrop(PB.Image, DragDropEffects.Copy Or DragDropEffects.Move)
        End If
    End Sub

    Private Sub PBs_DragEnter(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs)
        If e.Data.GetDataPresent(DataFormats.Bitmap) Then
            If My.Computer.Keyboard.CtrlKeyDown Then
                e.Effect = DragDropEffects.Copy
            Else
                e.Effect = DragDropEffects.Move
            End If
        Else
            e.Effect = DragDropEffects.None
        End If
    End Sub

    Private Sub PBs_DragOver(sender As Object, e As DragEventArgs)
        If e.Data.GetDataPresent(DataFormats.Bitmap) Then
            If My.Computer.Keyboard.CtrlKeyDown Then
                e.Effect = DragDropEffects.Copy
            Else
                e.Effect = DragDropEffects.Move
            End If
        Else
            e.Effect = DragDropEffects.None
        End If
    End Sub

    Private Sub PBs_DragDrop(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs)
        Dim PB As PictureBox = DirectCast(sender, PictureBox)
        Dim tmpImage As Image = PB.Image
        Dim tmptag As Integer = PB.Tag ` The Tag Temp
        PB.Image = e.Data.GetData(DataFormats.Bitmap)
        If e.Effect = DragDropEffects.Move Then
            If Not (PB Is Source) Then
                Source.Image = tmpImage
                Source.Tag = tmptag ` the first picbox gets the new tag
            End If
        End If
    End Sub

Answer 1

您可以将事件动态附加到所有图片框。

看这个例子

Public Class Form1


    Dim firstimage As Image
    Dim pold As PictureBox
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        PictureBox1.AllowDrop = True
        PictureBox2.AllowDrop = True
        PictureBox3.AllowDrop = True
        PictureBox4.AllowDrop = True
        PictureBox5.AllowDrop = True
        AddHandler PictureBox1.MouseMove, AddressOf p_MouseMove
        AddHandler PictureBox1.DragEnter, AddressOf p_DragEnter
        AddHandler PictureBox1.DragDrop, AddressOf p_DragDrop
        AddHandler PictureBox1.MouseEnter, AddressOf P_MouseEnter

        AddHandler PictureBox2.MouseMove, AddressOf p_MouseMove
        AddHandler PictureBox2.DragEnter, AddressOf p_DragEnter
        AddHandler PictureBox2.DragDrop, AddressOf p_DragDrop
        AddHandler PictureBox2.MouseEnter, AddressOf P_MouseEnter

        AddHandler PictureBox3.MouseMove, AddressOf p_MouseMove
        AddHandler PictureBox3.DragEnter, AddressOf p_DragEnter
        AddHandler PictureBox3.DragDrop, AddressOf p_DragDrop
        AddHandler PictureBox3.MouseEnter, AddressOf P_MouseEnter

        AddHandler PictureBox4.MouseMove, AddressOf p_MouseMove
        AddHandler PictureBox4.DragEnter, AddressOf p_DragEnter
        AddHandler PictureBox4.DragDrop, AddressOf p_DragDrop
        AddHandler PictureBox4.MouseEnter, AddressOf P_MouseEnter

        AddHandler PictureBox5.MouseMove, AddressOf p_MouseMove
        AddHandler PictureBox5.DragEnter, AddressOf p_DragEnter
        AddHandler PictureBox5.DragDrop, AddressOf p_DragDrop
        AddHandler PictureBox5.MouseEnter, AddressOf P_MouseEnter
    End Sub

    Private Sub P_MouseEnter(sender As Object, e As EventArgs)
        Dim p As PictureBox = sender
        pold = p
        Me.Text = pold.Name
    End Sub
    Private Sub p_MouseMove(ByVal sender As Object, ByVal e As MouseEventArgs)
        Dim p As PictureBox = sender
        If e.Button = MouseButtons.Left Then
            p.DoDragDrop(p.Image, DragDropEffects.All)

        End If
    End Sub
    Private Sub p_DragEnter(ByVal sender As Object, ByVal e As DragEventArgs)
        Dim p As PictureBox = sender
        firstimage = p.Image
        If e.Data.GetDataPresent(DataFormats.Bitmap) Then
            e.Effect = DragDropEffects.Copy
        Else
            e.Effect = DragDropEffects.None
        End If
    End Sub
    Private Sub p_DragDrop(ByVal sender As Object, ByVal e As DragEventArgs)
        Dim p As PictureBox = sender
        If (e.Data.GetDataPresent(DataFormats.Bitmap)) Then
            p.Image = CType((e.Data.GetData(DataFormats.Bitmap)), Bitmap)
            pold.Image = firstimage 'Set picturebox1 to the stored image
        End If
    End Sub
End Class

只需添加任意数量的图片框并为其附加 4 个不同的事件处理程序。

Answer 2

在 Drop 中，您正确地将来自 Target 的 Tag 存储在一个临时变量中，但只在 Source 中设置了 Tag，而不是 Target（您做了一半的交换）。

所以你错过了PB.Tag = Source.Tag。

改成：

Private Sub PBs_DragDrop(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs)
    Dim PB As PictureBox = DirectCast(sender, PictureBox)
    Dim tmpImage As Image = PB.Image
    Dim tmptag As Integer = PB.Tag ` The Tag Temp
    PB.Image = e.Data.GetData(DataFormats.Bitmap)
    PB.Tag = Source.Tag
    If e.Effect = DragDropEffects.Move Then
        If Not (PB Is Source) Then
            Source.Image = tmpImage
            Source.Tag = tmptag ` the first picbox gets the new tag
        End If
    End If
End Sub