Question

无法打印J并旋转它，只要我按下按钮1就会崩溃，但除了制作正确的J之外其他东西都能正常工作，我尝试更改点并且仍然会这样做

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等的值都是双倍的。将triangX和triangY更改为加倍或将结果转换为单个结果。

我在您的代码中看到两个问题首先你有12分，但你在那里使用14分

Call rotateFigure(triangX, triangY, 14, 14)

那里

或112分

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

和drawPolygon应为

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))

试图在VB中制作图形假设制作一个J并进行旋转，但它一直弄得一团糟

1 个答案: