用VB画4个点的NURBS曲线参考代码
Dim p(10000, 1) As Double
Dim num As Integer
Dim ptx As Single
Dim pty As Single
Dim w0, w1, w2, w3 As Single
Private Sub Command1_Click()
Dim t As Single
Dim i As Integer
Dim f0, f1, f2, f3 As Single
Picture1.DrawWidth = 3
For t = 0 To 1 Step 1 / 1000
w0 = Val(Form1.Text1.Text)
w1 = Val(Form1.Text2.Text)
w2 = Val(Form1.Text3.Text)
w3 = Val(Form1.Text4.Text)
f0 = 1 / 6 * (-t ^ 3 + 3 * t ^ 2 - 3 * t + 1)
f1 = 1 / 6 * (3 * t ^ 3 - 6 * t ^ 2 + 4)
f2 = 1 / 6 * (-3 * t ^ 3 + 3 * t ^ 2 + 3 * t + 1)
f3 = 1 / 6 * (t ^ 3)
ptx = (f0 * p(0, 0) * w0 + f1 * p(1, 0) * w1 + f2 * p(2, 0) * w2 + f3 * p(3, 0) * w3) / (f0 * w0 + f1 * w1 + f2 * w2 + f3 * w3)
pty = (f0 * p(0, 1) * w0 + f1 * p(1, 1) * w1 + f2 * p(2, 1) * w2 + f3 * p(3, 1) * w3) / (f0 * w0 + f1 * w1 + f2 * w2 + f3 * w3)
Picture1.PSet (ptx, pty), vbRed
Next
Picture1.DrawWidth = 1
For i = 0 To num - 2
Picture1.Line (p(i, 0), p(i, 1))-(p((i + 1), 0), p((i + 1), 1)), vbGreen
Next
End Sub
Private Sub Command2_Click()
Dim i As Integer
For i = 0 To num - 2
Picture1.Line (p(i, 0), p(i, 1))-(p((i + 1), 0), p((i + 1), 1)), vbWhite
Next
For i = 0 To num
Picture1.Circle (p(i, 0), p(i, 1)), 40, vbWhite
相关文档：
如何去优化你的VB程序帮助
1、如何去优化你的VB程序
Visual Basic 作为一种高级编程语言，它也有着不可避免的缺点---开发出的应用程序运行速度慢。如果我们能够程序做一些优化，那么情况将会大大改善。要优化程序运行的实际速度，常用的方法有三种：
1.尽量避免使用 Variant 变量。由于VB不能确定 Variant 变量的� ......
'代码:
Option Explicit
'======================用于查找进程和终止进程的API函数常数定义================ =====
Private Declare Function CreateToolhelpSnapshot Lib "kernel32" Alias "CreateToolhelp32Snapshot" (ByVal lFlags As Long, ByVal lProcessID As Long) As Long
Private Declare Function ProcessF ......
键盘是我们使用计算机的一个很重要的输入设备了，即使在鼠标大行其道的今天，很多程序依然离不开键盘来操作。但是有时候，一些重复性的，很繁琐的键盘操作 总会让人疲惫，于是就有了用程序来代替人们按键的方法，这样可以把很多重复性的键盘操作交给程序来模拟，省了很多精力，按键精灵就是这样的一个软件。那么 我们怎样才 ......
Private Declare Function URLDownloadToFile Lib "urlmon" Alias "URLDownloadToFileA" (ByVal pCaller As Long, ByVal szURL As String, ByVal szFileName As String, ByVal dwReserved As Long, ByVal lpfnCB As Long) As Long
Private Sub Command1_Click()
Dim Url As String, Filepath As String
Url = "h ......
全屏
Private Sub Form_Load()
Me.Width = Screen.Width
Me.Height = Screen.Height
Me.WindowState = 2
End Sub
置顶
1.在VB的通用代码里写入API声明
Private Declare Function SetWindowPos& Lib "user32" (ByVal hwnd As Long, _
&n ......
