在鼠標移動事件上的選擇框

Question

我想繪製一個選擇矩形圍繞我已標記在目標上的「鏡頭」。當它在「鏡頭」的「範圍」內時，我試圖讓它啓動，但它似乎隨機出現。下面是我想要的圖像（當鼠標懸停在它上面時，圍繞鏡頭的紅色選擇矩形）以及我的代碼。

Dim r As Rectangle 

Dim shotList As New List(Of Point) 
Dim scaleList As New List(Of Point) 
Dim ShotCount As New List(Of Point) 
Dim shotListBounds As New List(Of Rectangle) 



Private Sub DrawShotHover(g As Graphics, location As Point, ByVal radius As Integer) 
    Dim pn As New Pen(Brushes.Red, 2) 
    Dim dashValues As Single() = {2, 1, 2, 1} 
    pn.DashPattern = dashValues 
    g.DrawRectangle(pn, New Rectangle(location.X - radius, location.Y - radius, radius * 2, radius * 2)) 

End Sub 

Private Sub mPictureBox_MouseClick(sender As Object, e As MouseEventArgs) Handles mPictureBox.MouseClick 
    If e.Button = MouseButtons.Left Then 

      If shotFlag = True Then 

      Dim shot As New Point(e.X, e.Y) 
      shotList.Add(shot) 

      r = New Rectangle(e.X, e.Y, e.X + cboCaliber.EditValue/pLineDist()/2, e.Y + cboCaliber.EditValue/pLineDist()/2) 
      shotListBounds.Add(r) 

      shotDist = ShotDistance(shot) 
      mPictureBox.Invalidate() 

     End If 
End Sub 

Private Sub mPictureBox_Paint(sender As Object, e As PaintEventArgs) Handles mPictureBox.Paint 


    If LineScaleVal > 0 Then 
     'SELECTION RECT 
     If shotHoverSel = True Then 
      DrawShotHover(e.Graphics, r.Location, cboCaliber.EditValue/pLineDist()/2) 
     End If 

     'Point of Aim FLAG 
     Dim _poa As New POA(e.Graphics, New Point(_poaX, _poaY), cboCaliber.EditValue/pLineDist()/2) 

     'SHOT FLAG 
     For Each b As Point In shotList 
      Dim _Bullet As New Bullet(e.Graphics, b, cboCaliber.EditValue/pLineDist()/2, n) 
     Next 
End Sub 


Private Sub mPictureBox_MouseMove(sender As Object, e As MouseEventArgs) Handles mPictureBox.MouseMove 
    If shotListBounds.Count > 0 Then 
     For Each r As Rectangle In shotListBounds 
      Dim rad As Decimal = cboCaliber.EditValue/pLineDist() 
      If e.X >= r.X AndAlso e.X <= r.X + rad AndAlso e.Y >= r.Y AndAlso e.Y <= r.Y + rad Then 
       shotHoverSel = True 
       selShot = r.Location 
      End If 
     Next 
    End If 
End Sub 

Private Sub mPictureBox_MouseEnter(sender As Object, e As EventArgs) Handles mPictureBox.MouseEnter 
    If shotHoverSel = True Then 
     mPictureBox.Invalidate() 
    End If 
End Sub 



Private Sub mPictureBox_MouseLeave(sender As Object, e As EventArgs) Handles mPictureBox.MouseLeave 
    If shotHoverSel = False Then 
     mPictureBox.Invalidate() 
    End If 
End Sub 

Answer 1

但是實際上這個所謂的MouseEnter事件。製作一個處理mPictureBox.MouseEnter的方法