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GDI+ (Giao diện vẽ đồ họa), thư viện CoreGraphics và Cairo tạo thành khuôn khổ API vẽ trong wxPython. wx.GraphicsContext là đối tượng vẽ chính, sử dụng đối tượng này để tạo ra nhiều đối tượng Device Context khác nhau.

wx.DC là một lớp trừu tượng. Các lớp dẫn xuất của nó được sử dụng để hiển thị đồ họa và văn bản trên các thiết bị khác nhau. Các lớp Device Context là −

• wx.ScreenDC − Use this to paint on the screen, as opposed to an individual window.
• wx.ClientDC − Use this to paint on the client area of the window (the part without borders and other decorations), but do not use it from within an wxPaintEvent.
• wx.PaintDC − Use this to paint on the client area of the window, but only from within a wxPaintEvent.
• wx.WindowDC − Use this to paint on the whole area of the window, including decorations. This may not be available on non-Windows platforms.

Drawing API of wxPython offers different functions for drawing shape, text and image. Objects required for drawing purpose, like Colour, Pen, Brush and Font can also be constructed using GDI classes.

wx.Colour Class

Colour object represents combination of RGB (RED, Green and Blue) intensity values, each on the scale of 0-255. There are a few predefined colour objects like −

• wxBLACK
• wxBLUE
• wxCYAN
• wxGREEN
• wxYELLOW
• wxLIGHT_GREY
• wxRED
• wxWHITE

Color with custom combination of RGB values is formed as wx.Colour object.

wx.Colour(r,g,b)

wx.Pen Class

Pen object determines the colour, width and style of the shape of graphics like line, rectangle, circle etc.

Predefined Pen objects are −

Predefined Pen styles are −

wx.Brush Class

Brush is another elementary graphics object required to fill the backgrounds of shapes such as rectangle, ellipse, circle etc.

A custom Brush object requires wx.Colour and Brush style parameters. The following is a list of predefined brush styles −

wxPython has a number of functions that facilitate drawing different shapes, text and image.

Example

The above functions are implemented in the following example, making use of Pen, Brush, Colour and Font objects.

The complete code is as follows −

import wx 
 
class Mywin(wx.Frame): 
            
   def __init__(self, parent, title): 
      super(Mywin, self).__init__(parent, title = title,size = (500,300))  
      self.InitUI() 
         
   def InitUI(self): 
      self.Bind(wx.EVT_PAINT, self.OnPaint) 
      self.Centre() 
      self.Show(True)
		
   def OnPaint(self, e): 
      dc = wx.PaintDC(self) 
      brush = wx.Brush("white")  
      dc.SetBackground(brush)  
      dc.Clear() 
        
      dc.DrawBitmap(wx.Bitmap("python.jpg"),10,10,True) 
      color = wx.Colour(255,0,0)
      b = wx.Brush(color) 
		
      dc.SetBrush(b) 
      dc.DrawCircle(300,125,50) 
      dc.SetBrush(wx.Brush(wx.Colour(255,255,255))) 
      dc.DrawCircle(300,125,30) 
		
      font = wx.Font(18, wx.ROMAN, wx.ITALIC, wx.NORMAL) 
      dc.SetFont(font) 
      dc.DrawText("Hello wxPython",200,10) 
		
      pen = wx.Pen(wx.Colour(0,0,255)) 
      dc.SetPen(pen) 
      dc.DrawLine(200,50,350,50) 
      dc.SetBrush(wx.Brush(wx.Colour(0,255,0), wx.CROSS_HATCH)) 
      dc.DrawRectangle(380, 15, 90, 60) 
		
ex = wx.App() 
Mywin(None,''Drawing demo'') 
ex.MainLoop()

The above code produces the following output −

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