Public Class HighlightKey
Inherits Control
Private m_fillColor As Color = Color.White
Private m_opacity As Integer = 100
Private alpha As Integer
Private m_image As Image
Public Sub New()
SetStyle(ControlStyles.SupportsTransparentBackColor, True)
SetStyle(ControlStyles.Opaque, True)
Me.BackColor = Color.Transparent
Console.WriteLine("new Highlight key ")
End Sub
Public Property Image() As Image
Get
Return m_image
End Get
Set(ByVal value As Image)
m_image = value
End Set
End Property
Protected Overloads Overrides ReadOnly Property CreateParams() As CreateParams
Get
Dim cp As CreateParams = MyBase.CreateParams
cp.ExStyle = cp.ExStyle Or &H20
Return cp
End Get
End Property
Protected Overloads Overrides Sub OnBackColorChanged(ByVal e As EventArgs)
If Me.Parent IsNot Nothing Then
Parent.Invalidate(Me.Bounds, True)
End If
MyBase.OnBackColorChanged(e)
End Sub
Protected Overloads Overrides Sub OnParentBackColorChanged(ByVal e As EventArgs)
Me.Invalidate()
MyBase.OnParentBackColorChanged(e)
End Sub
Protected Overrides Sub OnPaintBackground(ByVal pevent As System.Windows.Forms.PaintEventArgs)
MyBase.OnPaintBackground(pevent)
End Sub
Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)
Dim g As Graphics = e.Graphics
Dim brush As New SolidBrush(Me.ForeColor)
Dim StringSize As New SizeF
alpha = (m_opacity * 255) / 100
If m_image IsNot Nothing Then
StringSize = g.MeasureString(Me.Text, Me.Font)
Dim x As Integer = (CInt(Me.m_image.Width) - CInt(StringSize.Width)) / 2
g.DrawImage(m_image, 0, 0, m_image.Width, m_image.Height)
g.DrawString(Me.Text, Me.Font, brush, x, 20)
End If
brush.Dispose()
g.Dispose()
MyBase.OnPaint(e)
End Sub
Public Function SetImgOpacity(ByVal imgPic As Image, ByVal imgOpac As Single) As Image
Dim bmpPic As New Bitmap(imgPic.Width, imgPic.Height)
Dim gfxPic As Graphics = Graphics.FromImage(bmpPic)
Dim cmxPic As New ColorMatrix()
cmxPic.Matrix33 = imgOpac
Dim iaPic As New ImageAttributes()
iaPic.SetColorMatrix(cmxPic, ColorMatrixFlag.[Default], ColorAdjustType.Bitmap)
gfxPic.DrawImage(imgPic, New Rectangle(0, 0, bmpPic.Width, bmpPic.Height), 0, 0, imgPic.Width, imgPic.Height, _
GraphicsUnit.Pixel, iaPic)
gfxPic.Dispose()
Return bmpPic
End Function
Private Sub HighlightKey_LocationChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.LocationChanged
Me.Refresh()
End Sub
Private Sub HighlightKey_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.TextChanged
Me.Refresh()
End Sub
End Class
我已经创建了一个如上的控件,这个控件允许我导入一个带有 alpha 通道和随机形状的 png。然后它可以显示在任何其他控件之上,即文本框、图片框等。并且背景应始终显示其下方的内容,而不是仅显示其父控件。
如果它是静态模式,它就可以工作,即在表格中静止。但是当我尝试拖动/移动它时,控件无法正确呈现自身,并且还位于其他控件下方。