VB.NET设计旋转文本控件
代码如下：
1 Public Class TextRotator 2 Inherits System.Windows.Forms.Control 3 4 Private msngRotationAngle As Single = 0 5 6 Public Property RotationAngle() As Single 7 Get 8 Return msngRotationAngle 9 End Get 10 Set(ByVal Value As Single) 11 If (msngRotationAngle >= -180) And (msngRotationAngle <= 180) Then 12 msngRotationAngle = Value 13 Me.Invalidate() ' Forces a repaint of the window 14 ' This is a method of the Control class 15 Else 16 ' Should raise an error here 17 End If 18 End Set 19 End Property 20 21 22 23 #Region " Windows Form Designer generated code " 24 25 Public Sub New() 26 MyBase.New() 27 28 'This call is required by the Windows Form Designer. 29 InitializeComponent() 30 31 'Add any initialization after the InitializeComponent() call 32 33 End Sub 34 35 'UserControl1 overrides dispose to clean up the component list. 36 Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean) 37 If disposing Then 38 If Not (components Is Nothing) Then 39 components.Dispose() 40 End If 41 End If 42 MyBase.Dispose(disposing) 43 End Sub 44 45 'Required by the Windows Form Designer 46 Private components As System.ComponentModel.IContainer 47 48 'NOTE: The following procedure is required by the Windows Form Designer 49 'It can be modified using the Windows Form Designer. 50 'Do not modify it using the code editor. 51 <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent() 52 components = New System.ComponentModel.Container() 53 End Sub 54 55 #End Region 56 57 Private Sub TextRotator_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint 58 ' Declare a brush, a font, and a graphics 59 ' object to use. 60 Dim bshBrush As Brush 61 Dim fntFont As Font 62 63 ' We can get the graphic object directly from 64 ' the PaintEventArgs parameter of the event. 65 Dim grfGraphics As Graphics = e.Graphics 66 67 ' Fix up the brush and the font. 68 bshBrush = New SolidBrush(Me.ForeColor) 69 fntFont = Me.Font 70 71 ' Need to see how far to shift the drawing of the text 72 ' so that it becomes visible. This calculation can be very 73 ' complex, but we will simplify it for the example by making 74 ' the starting point the center of the window for the control. 75 ' (Code below assumes Option Strict is Off). 76 Dim ShiftHorizontal As Single 77 Dim ShiftVertical As Single 78 ShiftHorizontal = Me.Size.Width * 0.5 79 ShiftVertical = Me.Size.Height * 0.5 80 81 ' Now draw some rotated text. 82 grfGraphics.RotateTransform(RotationAngle) 83 grfGraphics.DrawString(Me.Text, fntFont, bshBrush, _ 84 ShiftHorizontal, ShiftVertical) 85 grfGraphics.ResetTransform() 86 87 End Sub 88 89 Private Sub TextRotator_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.TextChanged 90 Me.Invalidate() 91 End Sub 92 93 94 End Class
