尝试在 VB 中制作图形假设制作 J 并进行旋转，但它一直弄得一团糟

Question

在让它打印 J 并旋转它时遇到问题，每当我点击按钮 1 时它就会崩溃，但除了制作正确的 J 之外，其他事情都可以正常工作，我尝试更改点，它仍然这样做

Public Class Form1
    Dim g As Graphics
    Dim triangX(12) As Single
    Dim triangY(12) As Single
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        PictureBox1.Width = 200
        PictureBox1.Height = 200
        PictureBox1.BackColor = Color.White
        g = PictureBox1.CreateGraphics
        Call initTriangCoords(triangX, triangY)
        Timer1.Interval = 200
        Timer1.Enabled = False
    End Sub
    Private Sub initTriangCoords(ByRef x() As Single, ByRef y() As Single)
        x(0) = 80 : y(0) = 80
        x(1) = 50 : y(1) = 70
        x(2) = 80 : y(2) = 70
        x(3) = 80 : y(3) = 80
        x(4) = 65 : y(4) = 80
        x(5) = 55 : y(5) = 80
        x(6) = 55 : y(6) = 130
        x(7) = 65 : y(7) = 130
        x(8) = 45 : y(8) = 120
        x(9) = 40 : y(9) = 130
        x(10) = 40 : y(10) = 110
        x(11) = 45 : y(11) = 110
    End Sub
    Private Sub drawPolygon(ByRef x() As Single, ByRef y() As Single, ByVal totPoints As Integer, ByRef g As Graphics)
        Dim i As Integer
        For i = 1 To totPoints - 1 Step 1
            g.DrawLine(Pens.Black, x(i), y(i), x(i + 1), y(i + 1))
        Next
        g.DrawLine(Pens.Black, x(1), y(1), x(totPoints), y(totPoints))
    End Sub
    Private Sub BtnDraw_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnDraw.Click
        PictureBox1.Refresh()
        Call drawPolygon(triangX, triangY, 12, g)
    End Sub
    Private Sub rotateFigure(ByRef x() As Single, ByRef y() As Single, ByVal totPoints As Integer, ByVal angle As Single)
        Dim nx As Single
        Dim ny As Single
        Dim i As Integer
        angle = angle * Math.PI / 180
        For i = 1 To totPoints Step 1
            nx = x(i) * Math.Cos(angle) - y(i) * Math.Sin(angle)
            ny = x(i) * Math.Sin(angle) + y(i) * Math.Cos(angle)
            x(i) = nx
            y(i) = ny
        Next i
    End Sub
    Private Sub rotateFigure2(ByRef x() As Single, ByRef y() As Single, ByVal totPoints As Integer, ByVal angle As Single)
        Dim nx As Single
        Dim ny As Single
        Dim i As Integer
        angle = angle * Math.PI / 180
        For i = 1 To totPoints Step 1
            nx = x(i) * Math.Sin(angle) - y(i) * Math.Cos(angle)
            ny = x(i) * Math.Cos(angle) + y(i) * Math.Sin(angle)
            x(i) = nx
            y(i) = ny
        Next i
    End Sub
    Private Sub BtnRotate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnRotate.Click
        Call rotateFigure(triangX, triangY, 14, 14)
    End Sub
    Private Sub rotateAroundPoint(ByRef x As Single, ByRef y As Single, ByVal angle As Single, ByVal xp As Single, ByVal yp As Single)

        Dim nx, ny As Single
        angle = angle * Math.PI / 180
        nx = ((x - xp) * Math.Cos(angle) - (y - yp) * Math.Sin(angle)) + xp
        ny = ((x - xp) * Math.Sin(angle) + (y - yp) * Math.Cos(angle)) + yp
        x = nx
        y = ny
    End Sub
    Private Sub rotateFigureAroundPivot(ByRef x() As Single, ByRef y() As Single, ByVal angle As Single, ByVal xp As Single, ByVal yp As Single, ByVal totpoints As Integer)
        Dim i As Integer
        For i = 1 To totpoints Step 1
            Call rotateAroundPoint(x(i), y(i), angle, xp, yp)
        Next
    End Sub
    Private Sub BtnRotateAroundPivot_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnRotateAroundPivot.Click
        Call rotateFigureAroundPivot(triangX, triangY, 12, triangX(0), triangY(0), 12)
    End Sub
    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        Call rotateFigureAroundPivot(triangX, triangY, 12, triangX(0), triangY(0), 12)
        PictureBox1.Refresh()
        Call drawPolygon(triangX, triangY, 12, g)
    End Sub
    Private Sub BtnActivateTimer_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnActivateTimer.Click
        Timer1.Enabled = True
    End Sub
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Call rotateFigure2(triangX, triangY, 112, 12)
    End Sub
End Class

Answer 1

Math.PI等的值都是双精度值。将triangX和triangY更改为双精度或将结果转换为单倍。

我在你的代码中看到的两个问题。
首先你有 12 分，但你在那里使用了 14 分

Call rotateFigure(triangX, triangY, 14, 14)

或那里有 112 个点

Call rotateFigure2(triangX, triangY, 112, 12)

vb.net 中的第二个数组以索引 0 开头。
如果要更改循环中的所有点，则需要使用

For i = 0 To totpoints - 1 Step 1

drawPolygon应该是

For i = 0 To totPoints - 2 Step 1
    g.DrawLine(Pens.Black, x(i), y(i), x(i + 1), y(i + 1))
Next
g.DrawLine(Pens.Black, x(0), y(0), x(totPoints - 1), y(totPoints - 1))