Question

我正在编写一个捕食者和猎物的模拟，并且已经构建了一个循环，因此它将一直继续，但由于某种原因，我的程序根本不运行循环。有任何想法吗？是的，我知道我的代码很乱，但我稍后会对此进行排序！

Public Class Form1
Dim intWidth As Integer = Screen.PrimaryScreen.Bounds.Width
Dim intHeight As Integer = Screen.PrimaryScreen.Bounds.Height
Dim StartBase As Integer = 10
Dim Hunter(100, 1) As Integer
Dim Hunted(100, 1) As Integer
Dim intCount As Integer = 0
Dim blnFinished As Integer = False
Dim blnFirst As Boolean = True
Private Sub Form1_keydown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles MyBase.KeyDown
    If e.KeyCode = Keys.Escape Then
        If MsgBox("Do you want to exit?", MsgBoxStyle.YesNo) = MsgBoxResult.Yes Then
            Application.Exit()
        End If
    End If
End Sub

Private Sub Form1_Load(sender As Object, e As System.EventArgs) Handles Me.Load
    Form1_Paint(sender, e)
    Do While (blnFinished = False)
        Movement()
        Form1_Paint(sender, e)
        Form1_keydown(sender, e)
    Loop
End Sub

Private Sub Form1_Paint(sender As Object, e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
    Dim X As Integer = 0
    Dim Y As Integer = 0
    If blnFirst = True Then
        RandomPosition(X, Y)
        For Me.intCount = 1 To StartBase
            X = CInt(Math.Floor(((intWidth) - 0 + 1) * Rnd())) + 0               'Assigns a random x coordinate
            Y = CInt(Math.Floor((intHeight - 250) - 0 + 1) * Rnd()) + 0        'Assigns a random y coordinate
            Hunted(intCount, 0) = X
            Hunted(intCount, 1) = Y                                         'Saves the x and y value to Hunted array
            e.Graphics.FillRectangle(Brushes.LightGreen, X, Y, 15, 15)      'Draws the hunted to the screen with earlier values
            X = CInt(Math.Floor(((intWidth) - 0 + 1) * Rnd())) + 0               'Assigns a random x coordinate
            Y = CInt(Math.Floor((intHeight - 250) - 0 + 1) * Rnd()) + 0        'Assigns a random y coordinate
            Hunter(intCount, 0) = X
            Hunter(intCount, 1) = Y                                         'Saves the x and y value to Hunted array
            e.Graphics.FillRectangle(Brushes.Maroon, X, Y, 15, 15)   'Draws the hunted to the screen with earlier values
        Next
        blnFirst = False
    Else
        For Me.intCount = 1 To StartBase
            X = Hunted(intCount, 0)
            Y = Hunted(intCount, 1)
            e.Graphics.FillRectangle(Brushes.LightGreen, X, Y, 15, 15)
            X = Hunter(intCount, 0)
            Y = Hunter(intCount, 1)
            e.Graphics.FillRectangle(Brushes.Maroon, X, Y, 15, 15)
        Next
    End If
    e.Graphics.FillRectangle(Brushes.White, 0, intHeight - 235, intWidth, 200)
End Sub

Private Sub RandomPosition(X, Y)
    Randomize()
    X = CInt(Math.Floor((Width - 0 + 1) * Rnd())) + 0
    Y = CInt(Math.Floor((Height - 250) - 0 + 1) * Rnd()) + 0
End Sub

Private Sub Movement()
End Sub
End Class

Answer 1

您正在直接调用Form_Paint并从sender传递e和Form_Load的值。但是，Form_Paint期望e的类型为System.Windows.Forms.PaintEventArgs，而您传入的类型为System.EventArgs，因为这是传递给Form_Load的内容。 System.EventArgs没有名为Graphics的属性。所以下面的行（和其他类似的）可能会引发异常，因为你传入的e的值没有Graphics属性：

e.Graphics.FillRectangle(Brushes.LightGreen, X, Y, 15, 15)

我认为你没有看到异常，因为它发生在Form_Load中。在调试模式下运行程序并查看输出窗口。可能会出现例外情况。或者在代码周围加上Try Catch。

您最好使用计时器并在其内部的刻度事件中调用Form1.Refresh()。这将正确触发Paint事件。

没有运行我的Do While循环

1 个答案: