严重求助 ，闪烁的点，为什么总是搞不定？

Question

Imports System.Drawing
Imports System.drawing.drawing2d

Public Class Form1
    Inherits System.Windows.Forms.Form
    Private WithEvents tmr As New System.Timers.Timer(10)
    Private rnd As New Random

Private Sub Form1_SizeChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.SizeChanged
        Me.Invalidate()
End Sub

Dim x, y, z, w As Single

    Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        Dim t As Single
        Try
            t = DirectCast(sender, System.Windows.Forms.TextBox).Text
            x = t
        Catch
        End Try
        myfunc()
        Me.Invalidate()
    End Sub
    Private Sub TextBox2_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox2.TextChanged
        Dim t As Single
        Try
            t = DirectCast(sender, System.Windows.Forms.TextBox).Text
            y = t
        Catch
        End Try
        myfunc()
        Me.Invalidate()
    End Sub
    Private Sub TextBox4_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox4.TextChanged
        Dim t As Single
        Try
            t = DirectCast(sender, System.Windows.Forms.TextBox).Text
            w = t
        Catch
        End Try
        myfunc()
        Me.Invalidate()
    End Sub
    Private Sub TextBox3_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox3.TextChanged
        Dim t As Single
        Try
            t = DirectCast(sender, System.Windows.Forms.TextBox).Text
            z = t
        Catch
        End Try
        myfunc()
        Me.Invalidate()
    End Sub

Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)

End Sub

Private Sub tmr_Elapsed(ByVal sender As Object, ByVal e As System.Timers.ElapsedEventArgs) Handles tmr.Elapsed
        Me.CreateGraphics.FillEllipse(New SolidBrush(Color.FromArgb(rnd.Next(0, 255), rnd.Next(0, 255), rnd.Next(0, 255))), New Rectangle(x - 3, y - 3, 6, 6))
    End Sub

    Public Sub point()
        Dim rect1 As Rectangle = Rectangle.FromLTRB( x - 3, y - 3,  x + 3, y+ 3)
        Dim rect2 As Rectangle = Rectangle.FromLTRB( w - 2, z- 2,  w + 2, z + 2)
        Dim pen1 As Pen
        pen1 = New Pen(Color.Black)
        Dim brush1 As Brush
        brush1 = New SolidBrush(Color.FromArgb(225, Color.Black))
        Me.CreateGraphics.DrawEllipse(pen1, rect1)
        Me.CreateGraphics.FillEllipse(brush1, rect1)
        Me.CreateGraphics.DrawEllipse(pen1, rect2)
        Me.CreateGraphics.FillEllipse(brush1, rect2)
    End Sub

    Private Sub myfunc()
        If If 140 < x and x< 180  and y<100 Then
         tmr_Elapsed(Nothing, Nothing)
        Else
        Call point()
        End If
    End Sub
End Class


根据版主建议 http://social.microsoft.com/Forums/zh-CN/vbasiczhchs/thread/99e921fb-2a3c-4b25-bad9-4e31a4ad8239
 我的程序已经作了一些修改，我想用if 语句的来实现画闪烁的点和不闪烁的点，代码都是正确的，为什么达不到我的要求呢？

 

---

visual studio 2008

Answer 1

 Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        tmr.Enabled = True
    End Sub

---

http://feiyun0112.cnblogs.com/

Answer 2

Imports System.Drawing
Imports System.drawing.drawing2d

Public Class Form1
    Inherits System.Windows.Forms.Form
    Private WithEvents tmr As New System.Timers.Timer(10)
    Private rnd As New Random

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        tmr.Start()
 End Sub

Private Sub Form1_SizeChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.SizeChanged
        Me.Invalidate()
End Sub

Dim x, y, z, w As Single

    Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        Dim t As Single
        Try
            t = DirectCast(sender, System.Windows.Forms.TextBox).Text
            x = t
        Catch
        End Try
        myfunc()
        Me.Invalidate()
    End Sub
    Private Sub TextBox2_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox2.TextChanged
        Dim t As Single
        Try
            t = DirectCast(sender, System.Windows.Forms.TextBox).Text
            y = t
        Catch
        End Try
        myfunc()
        Me.Invalidate()
    End Sub
    Private Sub TextBox4_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox4.TextChanged
        Dim t As Single
        Try
            t = DirectCast(sender, System.Windows.Forms.TextBox).Text
            w = t
        Catch
        End Try
        myfunc()
        Me.Invalidate()
    End Sub
    Private Sub TextBox3_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox3.TextChanged
        Dim t As Single
        Try
            t = DirectCast(sender, System.Windows.Forms.TextBox).Text
            z = t
        Catch
        End Try
        myfunc()
        Me.Invalidate()
    End Sub

Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)

End Sub

Private Sub tmr_Elapsed(ByVal sender As Object, ByVal e As System.Timers.ElapsedEventArgs) Handles tmr.Elapsed
        Me.CreateGraphics.FillEllipse(New SolidBrush(Color.FromArgb(rnd.Next(0, 255), rnd.Next(0, 255), rnd.Next(0, 255))), New Rectangle(x - 3, y - 3, 6, 6))
    End Sub

    Public Sub point()
        Dim rect1 As Rectangle = Rectangle.FromLTRB( x - 3, y - 3,  x + 3, y+ 3)
        Dim rect2 As Rectangle = Rectangle.FromLTRB( w - 2, z- 2,  w + 2, z + 2)
        Dim pen1 As Pen
        pen1 = New Pen(Color.Black)
        Dim brush1 As Brush
        brush1 = New SolidBrush(Color.FromArgb(225, Color.Black))
        Me.CreateGraphics.DrawEllipse(pen1, rect1)
        Me.CreateGraphics.FillEllipse(brush1, rect1)
        Me.CreateGraphics.DrawEllipse(pen1, rect2)
        Me.CreateGraphics.FillEllipse(brush1, rect2)
    End Sub

    Private Sub myfunc()
        If If 140 < x and x< 180  and y<100 Then
         tmr_Elapsed(Nothing, Nothing)
        Else
        Call point()
        End If
    End Sub
End Class

不好意思，代码修正好。重新回到话题。

---

visual studio 2008

Answer 3

？？

---

visual studio 2008

Answer 4

我试了没问题

除了这里多写了个if
 If If 140 < x and x< 180  and y<100 Then

---

http://feiyun0112.cnblogs.com/

Answer 5

feiyun0112 说:

我试了没问题

除了这里多写了个if
 If If 140 < x and x< 180  and y<100 Then

---

http://feiyun0112.cnblogs.com/

问题时当x和y 不在 140 < x and x< 180  and y<100这个范围时，窗体上画的还是闪烁的点。窗体上画的还是闪烁的点。

---

visual studio 2008

Answer 6

  Private Sub tmr_Elapsed(ByVal sender As Object, ByVal e As System.Timers.ElapsedEventArgs) Handles tmr.Elapsed
        If 140 < x And x < 180 And y < 100 Then
            Me.CreateGraphics.FillEllipse(New SolidBrush(Color.FromArgb(rnd.Next(0, 255), rnd.Next(0, 255), rnd.Next(0, 255))), New Rectangle(x - 3, y - 3, 6, 6))
        Else
            Call point()
        End If
    End Sub

Private Sub myfunc()

        tmr_Elapsed(Nothing, Nothing)
 
    End Sub

---

http://feiyun0112.cnblogs.com/

Answer 7

feiyun0112 说:

  Private Sub tmr_Elapsed(ByVal sender As Object, ByVal e As System.Timers.ElapsedEventArgs) Handles tmr.Elapsed
        If 140 < x And x < 180 And y < 100 Then
            Me.CreateGraphics.FillEllipse(New SolidBrush(Color.FromArgb(rnd.Next(0, 255), rnd.Next(0, 255), rnd.Next(0, 255))), New Rectangle(x - 3, y - 3, 6, 6))
        Else
            Call point()
        End If
    End Sub

Private Sub myfunc()

        tmr_Elapsed(Nothing, Nothing)
 
    End Sub

---

http://feiyun0112.cnblogs.com/

成功了，不好意思，恢复完了。

---

visual studio 2008