我需要在 vb.net 传递给这个子例程什么

Question

Public Sub DrawRectangleInt(e As PaintEventArgs)
        ' Create pen. 
        Dim blackPen As New Pen(Color.Black, 3)
        ' Create location and size of rectangle. 
        Dim x As Integer = 0
        Dim y As Integer = 0
        Dim width As Integer = 200
        Dim height As Integer = 200
        ' Draw rectangle to screen.
        e.Graphics.DrawRectangle(blackPen, x, y, width, height)
    End Sub

当呼叫潜艇时：

DrawRectangleInt()

我收到一个错误，说我需要为"e"传递一些东西，但是呢？

谢谢。

Answer 1

你可以从 paint 事件中调用该 sub 并将 e 变量传递给 sub，或者在 sub 中创建 Graphics 对象。"使用/结束使用"块可正确释放对象。

Public Sub DrawRectangleInt()
  ' Create pen. 
  Using blackPen As New Pen(Color.Black, 3)
    ' Create location and size of rectangle. 
    Dim x As Integer = 0
    Dim y As Integer = 0
    Dim width As Integer = 200
    Dim height As Integer = 200
    ' Draw rectangle to screen.
    Using g As Graphics = Me.CreateGraphics
      g.DrawRectangle(blackPen, x, y, width, height)
    End Using
  End Using
End Sub