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Dim url As String=" 网址"
成都创新互联公司成立10多年来,这条路我们正越走越好,积累了技术与客户资源,形成了良好的口碑。为客户提供成都网站制作、做网站、网站策划、网页设计、申请域名、网络营销、VI设计、网站改版、漏洞修补等服务。网站是否美观、功能强大、用户体验好、性价比高、打开快等等,这些对于网站建设都非常重要,成都创新互联公司通过对建站技术性的掌握、对创意设计的研究为客户提供一站式互联网解决方案,携手广大客户,共同发展进步。
Dim httpReq As System.Net.HttpWebRequest
Dim httpResp As System.Net.HttpWebResponse
Dim httpURL As New System.Uri(url)
httpReq = CType(WebRequest.Create(httpURL), HttpWebRequest)
httpReq.Method = "GET"
httpResp = CType(httpReq.GetResponse(), HttpWebResponse)
httpReq.KeepAlive = False ' 获取或设置一个值,该值指示是否与
Internet资源建立持久连接。
Dim reader As StreamReader = _
New StreamReader(httpResp.GetResponseStream,
System.Text.Encoding.GetEncoding(-0))
Dim respHTML As String = reader.ReadToEnd() 'respHTML就是网页源代码
你把问题想简单点,直接在PANEL空间上使用GD+画指针就行了。算出两点划线还不容易么?用图片的话需要旋转,而且锯齿非常严重@!
如果你的计算机安装了.Net环境的话,(Vista以上版本都默认安装了,XP需要下载.Net Framework来安装),系统盘上Windows目录下会有一个Microsoft.Net目录,里面的2.0目录里有相应的编译器。C#语言的编译器是csc.exe,VB.Net语言的编译器是vbc.exe。用命令行的方式就能把源码编译成可执行程序。如csc 123.cs 123.exe。你也可以用集成开发环境,如VS2005或VS2008,用他们打开源码,并添加一个解决方案,就能编译并调试执行。不过VS2005或VS2008都比较大,几个G大小,另外还有一个比较小巧又好用的集成开发环境叫SharpDevelop,只有十几M大小,他和VS2005几乎一样好用,并能生产支持Vista界面的程序,不过只能编译C#源码。
如果是.NET平台的,你可以使用ComponentOne Enterprise 全功能.NET控件集中的布局控件实现。也可以试试ComponentOne的LinearGauge 控件,这是一个线性仪表器,显示为一个值和象征参考值的可选范围。线性仪表盘(LinearGauge)控件提供了一个 ShowText 属性,用来决定哪些值以文本显示。
》》传送门:网页链接
就
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Hand类的代码:
Public MustInherit Class Hand
Protected gp As GraphicsPath = New GraphicsPath()
Protected gpBase As GraphicsPath = Nothing
Protected midX As Integer = 150 ‘默认的窗体
Protected midY As Integer = 150 ‘中心位置
‘构造器,得到窗体中心位置
Public Sub New(ByVal theForm As Form1)
midX = (theForm.ClientRectangle.Left + theForm.ClientRectangle.Right) / 2
midY = (theForm.ClientRectangle.Top + theForm.ClientRectangle.Bottom) / 2
End Sub
MustOverride Sub Transform(ByVal d As DateTime)
‘绘制指针路径
Overridable Sub Draw(ByVal g As Graphics)
Dim aPen As Pen = New Pen(Brushes.Black, 4F)
g.DrawPath(aPen, gp)
g.FillPath(Brushes.Black, gp)
aPen.Dispose()
End Sub
‘使用矩阵实现路径(gp)的旋转
Public Sub Rotate(ByVal angle As Double)
gp = CType(gpBase.Clone(), GraphicsPath)
Dim mTransform As Matrix = New Matrix()
mTransform.RotateAt(CType(angle,Single),NewPointF(midX,midY))
gp.Transform(mTransform)
End Sub
End Class
为了节省篇幅,上面的代码省略了引入命名空间的语句。
下面是分针(MinuteHand)类的定义:
Public Class MinuteHand
Inherits Hand
‘构造器,生成绘制分针的路径(gp)
Public Sub New(ByVal myForm As Form1)
MyBase.New(myForm)
gp.AddLine(midX, midY, midX, 45)
gp.AddLine(midX, 45, midX - 3, 50)
gp.AddLine(midX - 3, 50, midX + 3, 50)
gp.AddLine(midX + 3, 50, midX, 45)
gpBase = CType(gp.Clone(), GraphicsPath)
End Sub
‘Transform方法取得系统当前时间,并旋转时钟指针。
Public Overrides Sub Transform(ByVal d As DateTime)
Dim minuteTime As Double = (CDbl(d.Minute) + CDbl(d.Second / 60))
Dim angle As Double = (CDbl(minuteTime) / 60) * 360
Rotate(angle)
End Sub
End Class
对所有的指针旋转的方法都是相同的,因此在基类中实现。由于时针和秒针的实现与分针相似,所不同者,只在于构造器中绘制的指针路径不同和Transform方法中转动的角度不同,在这里就不在赘述了。
另外还需要提一下的是画时钟表面的代码,时钟表面用ClockFace类来实现。这个类首先画一个圆代表时钟,然后画上米老鼠的图案,最后在相应的位置画上数字1~12代表12个小时。
Public Sub Draw(ByVal g As Graphics)
DrawClockFace(g)
DrawImage(g)
DrawNumbers(g)
DrawPin(g)
End Sub
下面是ClockFace类的属性:
Private ClockRectangle As Rectangle
Private ClockFont As Font = New Font("Arial", 12)
Private midPoint As Point
Private ClockImage As Bitmap
Private Const IMAGEX As Integer = 50
Private Const IMAGEY As Integer = 50
DrawClockFace方法用来画时钟表面:
Private Sub DrawClockFace(ByVal g As Graphics)
g.FillEllipse(Brushes.White, ClockRectangle.Left + 10, ClockRectangle.Top + 10, ClockRectangle.Width - 20, ClockRectangle.Height - 20)
g.DrawEllipse(Pens.Black, ClockRectangle.Left + 10, ClockRectangle.Top + 10, ClockRectangle.Width - 20, ClockRectangle.Height - 20)
End Sub
然后用Graphics对象的DrawImage方法画出米老鼠的图片:
Private Sub DrawImage(ByVal g As Graphics)
Dim nWidth As Integer = ClockImage.Width
Dim nHeight As Integer = ClockImage.Height
Dim destRect As Rectangle = New Rectangle(midPoint.X - IMAGEX / 2, midPoint.Y - IMAGEY / 2, IMAGEX, IMAGEY)
g.DrawImage(ClockImage, destRect)
End Sub
数字在时钟上的位置是用sin和cos函数计算的:
Private Sub DrawNumbers(ByVal g As Graphics)
Dim count As Integer = 1
Dim a As Double
For a = 0 To 2 * Math.PI Step 2 * Math.PI / 12
Dim x As Double = (ClockRectangle.Width - 70) / 2 * Math.Cos(a - Math.PI / 3) + (ClockRectangle.Width - 70) / 2 + 25
Dim y As Double = (ClockRectangle.Width - 70) / 2 * Math.Sin(a - Math.PI / 3) + (ClockRectangle.Width - 70) / 2 + 20
g.DrawString(Convert.ToString(count), ClockFont, Brushes.Black, CType(x, Single), CType(y, Single), New StringFormat())
count += 1
Next
End Sub
最后是窗体文件(Form1.vb):
Public Class Form1
Inherits System.Windows.Forms.Form
Private MyMinuteHand As MinuteHand
Private MyHourHand As HourHand
Private MySecondHand As SecondHand
Private TheClockFace As ClockFace
Private FirstTick As Boolean = False
‘在窗体的OnPaint事件中取得Graphics对象
Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)
If (FirstTick = False) Then Exit Sub
Dim g As Graphics = e.Graphics
TheClockFace.Draw(g)
MyHourHand.Draw(g)
MyMinuteHand.Draw(g)
MySecondHand.Draw(g)
TheClockFace.DrawPin(g)
End Sub
‘计时器事件
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
MySecondHand.Transform(DateTime.Now)
MyHourHand.Transform(DateTime.Now)
MyMinuteHand.Transform(DateTime.Now)
FirstTick = True
Invalidate()