GDI+ - Árvore de Natal de 2009
Um exemplo da utilização das capacidades da framework para trabalhar com GDI+ O código abaixo irá produzir uma árvore de Natal desenhada com base em 4 triângulos de diferentes tamanhos.
'depois de abrir um projecto novo, no código do form:
Imports System.Drawing
Imports System.Drawing.Drawing2D
Public Class Form1
Private Luzes As New List(Of Point)
Private R As New Random
Private FNT As New Font("Arial", 20, FontStyle.Bold)
Private WithEvents Piscar As New Timer With {.Interval = 500, .Enabled = True}
Private Sub Form1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Click
End
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Me.Size = New Size(250, 600)
Me.Top = CInt((Screen.PrimaryScreen.Bounds.Height / 2) - (Me.Height / 2))
Me.Left = CInt((Screen.PrimaryScreen.Bounds.Width / 2) - (Me.Width / 2))
Me.FormBorderStyle = Windows.Forms.FormBorderStyle.None
Dim B As New Bitmap(ClientSize.Width, ClientSize.Height)
Dim G As Graphics = Graphics.FromImage(B)
Dim BGLGB As New LinearGradientBrush(New Point(CInt(B.Width / 2), 0), New Point(CInt(B.Width / 2), 600), Color.DarkBlue, Color.Blue)
'Os gradientes, de diferentes tamanhos para todos os 4 triângulos
Dim LGB1 As New LinearGradientBrush(New Point(125, 20), New Point(125, 470), Color.White, Color.DarkGreen)
Dim LGB2 As New LinearGradientBrush(New Point(125, 20), New Point(125, 353), Color.White, Color.DarkGreen)
Dim LGB3 As New LinearGradientBrush(New Point(125, 0), New Point(125, 236), Color.White, Color.DarkGreen)
Dim LGB4 As New LinearGradientBrush(New Point(125, 0), New Point(125, 120), Color.White, Color.DarkGreen)
'Atribuição dos 3 pontos para a produção dos triângulos
Dim T1() As PointF = {New PointF(125, 20), New Point(10, 470), New PointF(230, 470)}
Dim T2() As PointF = {New PointF(125, 20), New Point(20, 353), New PointF(220, 353)}
Dim T3() As PointF = {New PointF(125, 20), New Point(30, 236), New PointF(210, 236)}
Dim T4() As PointF = {New PointF(125, 20), New Point(40, 120), New PointF(200, 120)}
'Para pintar o céu azul
G.FillRectangle(BGLGB, 0, 0, B.Width, B.Height)
Dim R As New Random
'Para pintar as estrelas, aleatóriamente
For P = 1 To 500
G.FillEllipse(Brushes.White, R.Next(0, B.Width), R.Next(0, B.Height), 2, 2)
Next
'Atribuição dos pontos para o polígono que representa a estrela
Dim Estrela() As PointF = {New PointF(0 + 115, 10), New PointF(5 + 115, 10), _
New PointF(10 + 115, 0), New PointF(15 + 115, 10), _
New PointF(20 + 115, 10), New PointF(15 + 115, 15), _
New PointF(20 + 115, 25), New PointF(10 + 115, 18), _
New PointF(0 + 115, 25), New PointF(5 + 115, 15), _
New PointF(0 + 115, 10), New PointF(0 + 115, 0)}
'Desenho dos triângulos com os pontos previamente colocados. Rebordo e preenchimento
G.FillPolygon(LGB1, T1) : G.DrawPolygon(New Pen(Color.Black, 2), T1)
G.FillPolygon(LGB2, T2) : G.DrawPolygon(New Pen(Color.Black, 2), T2)
G.FillPolygon(LGB3, T3) : G.DrawPolygon(New Pen(Color.Black, 2), T3)
G.FillPolygon(LGB4, T4) : G.DrawPolygon(New Pen(Color.Black, 2), T4)
'Desenho do polígono que representa a estrela
G.FillPolygon(Brushes.Yellow, Estrela)
'Desenho do tronco da árvore
G.FillRectangle(Brushes.Brown, 100, 470, 50, (600 - 470))
'Desenho do rebordo do tronco da árvore
G.DrawRectangle(New Pen(Color.Black, 2), 100, 470, 50, (600 - 470))
'Colocação abstracta da posição das luzes
Luzes.Add(New Point(72, 105)) : Luzes.Add(New Point(100, 70)) :
Luzes.Add(New Point(136, 101)) : Luzes.Add(New Point(176, 105))
Luzes.Add(New Point(127, 52)) : Luzes.Add(New Point(90, 134))
Luzes.Add(New Point(149, 139)) : Luzes.Add(New Point(121, 160))
Luzes.Add(New Point(69, 206)) : Luzes.Add(New Point(133, 215))
Luzes.Add(New Point(106, 186)) : Luzes.Add(New Point(167, 180))
Luzes.Add(New Point(152, 217)) : Luzes.Add(New Point(68, 251))
Luzes.Add(New Point(128, 298)) : Luzes.Add(New Point(165, 253))
Luzes.Add(New Point(109, 256)) : Luzes.Add(New Point(52, 333))
Luzes.Add(New Point(75, 296)) : Luzes.Add(New Point(127, 328))
Luzes.Add(New Point(187, 328)) : Luzes.Add(New Point(170, 286))
Luzes.Add(New Point(63, 369)) : Luzes.Add(New Point(169, 394))
Luzes.Add(New Point(94, 418)) : Luzes.Add(New Point(120, 368))
Luzes.Add(New Point(36, 441)) : Luzes.Add(New Point(113, 453))
Luzes.Add(New Point(201, 429)) : Luzes.Add(New Point(142, 447))
Luzes.Add(New Point(186, 386))
Me.BackgroundImage = B
End Sub
Private Sub Piscar_Tick(ByVal sender As Object, ByVal e As System.EventArgs) Handles Piscar.Tick
Dim G As Graphics = Me.CreateGraphics
'Desenhar um novo círculo, com uma cor diferente, nas posições das luzes previamente definidas
For Each P As Point In Luzes
Dim TB As New SolidBrush(DarCor())
G.FillEllipse(TB, P.X, P.Y, 10, 10)
Next
'Cálculo de tamanho e posicionamento da palavra FELIZ NATAL, desenhada 3 vezes com um pequeno offset
'para simular profundidade
Dim TempMsg As String = "FELIZ NATAL"
Dim TempTam As SizeF = G.MeasureString(TempMsg, FNT)
G.DrawString(TempMsg, FNT, New SolidBrush(DarCor), 125 - (TempTam.Width / 2), 500)
G.DrawString(TempMsg, FNT, New SolidBrush(DarCor), 125 - (TempTam.Width / 2) + 2, 500 + 2)
G.DrawString(TempMsg, FNT, New SolidBrush(DarCor), 125 - (TempTam.Width / 2) + 4, 500 + 4)
End Sub
'Dar uma cor aleatória, dentro das que se querem disponibilizar
Private Function DarCor() As Color
Dim Cor1 As Color = Color.LightGreen
Dim Cor2 As Color = Color.Blue
Dim Cor3 As Color = Color.Red
Dim Cor4 As Color = Color.Yellow
Select Case CInt(R.Next(1, 4))
Case 1 : Return Cor1
Case 2 : Return Cor2
Case 3 : Return Cor3
Case 4 : Return Cor4
End Select
End Function
End Class
Resultado final
