Question

我正在使用wxPyhon编写简单的GUI并遇到一些问题。
我的应用程序做了一些简单的事情：它在表单上绘制三角形并在用户单击箭头按钮或在表单上拖动鼠标光标时旋转它。
我现在看到的问题如下：
1.然后我快速拖动鼠标左右三角形旋转，同时保持旧图像可见一小段时间。当快速移动光标一段时间时，表单上的图形看起来像2或3个三角形 2.如果我将窗体扩展到整个屏幕大小，则三角形移动不平滑，从旧外观到新外观的小跳跃。我在旋转过程中查看了鼠标光标的坐标，注意到它们是用间隙跟踪的。我的朋友告诉我，这是因为每次我用魔杖旋转三角形时，我都会重新绘制应用程序的整个窗口。这就是为什么它工作缓慢并且减慢了鼠标光标的跟踪速度。

要刷新视图，我正在使用wx.Panel.Refresh（）方法。作为绘图上下文我正在使用wx.BufferedDC（）

请告诉我如何在wxPython表单上绘制正确的动态更改图片/绘图，尤其是我在该应用程序中的方式。

我可以将我的代码放在这里，但它太长了。所以如果我必须告诉我更多关于我的情况 - 请问我，我会回答。

谢谢！

class SimpleGraphics(wx.Panel):
    def __init__(self, parent, size=(50, 50)):
        super(SimpleGraphics, self).__init__(parent,
                                     size=size,
                                     style=wx.NO_BORDER)

        self.color = "Black"
        self.thickness = 2
        self.pen = wx.Pen(self.color, self.thickness, wx.SOLID)
        self.MARGIN = 1 #px
        self.points = [[0.0, 0.5], [0.5, 0.0], [-0.5, -0.5]]
        self.pos = (0, 0)
        self.cur_vector = Vector2D(1, 1)

        self.InitBuffer()
        self.Bind(wx.EVT_SIZE, self.OnSize)
        self.Bind(wx.EVT_IDLE, self.OnIdle)
        self.Bind(wx.EVT_KEY_DOWN, self.OnKeyArrow)
        # MOUSE TRACKING
        self.Bind(wx.EVT_LEFT_DOWN, self.OnLeftDown)
        self.Bind(wx.EVT_LEFT_UP, self.OnLeftUp)
        self.Bind(wx.EVT_MOTION, self.OnMotion)

        self.Bind(wx.EVT_PAINT, self.OnPaint)


    def InitBuffer(self):
        self.client_size = self.GetClientSize()
        self.buffer = wx.EmptyBitmap(self.client_size.width, self.client_size.height)
        dc = wx.BufferedDC(None, self.buffer)
        dc.SetBackground(wx.Brush(self.GetBackgroundColour()))
        dc.Clear()
        self.DrawImage(dc)
        self.reInitBuffer = False

    def OnSize(self, event):
        self.reInitBuffer = True

    def repaint_the_view(self):
        self.InitBuffer()
        self.Refresh()

    def OnIdle(self, event):
        if self.reInitBuffer:
            self.repaint_the_view()

    def OnKeyArrow(self, event):
        key_code = event.GetKeyCode()
        if key_code == wx.WXK_LEFT:
            self.rotate_points(degrees_to_rad(5))
        elif key_code == wx.WXK_RIGHT:
            self.rotate_points(degrees_to_rad(-5))
        self.repaint_the_view()
        event.Skip()

    def OnLeftDown(self, event):
        # get the mouse position and capture the mouse 
        self.pos = event.GetPositionTuple()
        self.cur_vector = create_vector2d(self.pos[0], self.pos[1],
                                         self.client_size.width / 2,
                                         self.client_size.height / 2)
        self.CaptureMouse()

    def OnLeftUp(self, event):
        #release the mouse
        if self.HasCapture():
            self.ReleaseMouse()

    def OnMotion(self, event):
        if event.Dragging() and event.LeftIsDown():
            newPos = event.GetPositionTuple()
            new_vector = create_vector2d(newPos[0], newPos[1],
                                         self.client_size.width / 2,
                                         self.client_size.height / 2)
            if new_vector.lenth() > 0.00001:
                c = cos_a(self.cur_vector, new_vector)
                s = sin_a(self.cur_vector, new_vector)
                rot_matr = rotation_matrix(s, c)
                self.rotate_points(rot_matr=rot_matr)
                dc = wx.BufferedDC(wx.ClientDC(self), self.buffer) # this line I've added after posting the question
                self.repaint_the_view()
                self.cur_vector = new_vector
        event.Skip()

    def OnPaint(self, event):
        wx.BufferedPaintDC(self, self.buffer)

    def DrawImage(self, dc):
        dc.SetPen(self.pen)
        new_points = self.convetr_points_to_virtual()
        dc.DrawPolygon([wx.Point(x, y) for (x, y) in new_points])

    def to_x(self, X_Log):
        X_Window = self.MARGIN + (1.0 / 2) * (X_Log + 1) * (self.client_size.width - 2 * self.MARGIN)
        return int(X_Window)

    def to_y(self, Y_Log):
        Y_Window = self.MARGIN + (-1.0 / 2) * (Y_Log - 1) * (self.client_size.height - 2 * self.MARGIN)
        return int(Y_Window)

    def convetr_points_to_virtual(self):
        return [(self.to_x(x), self.to_y(y)) for (x, y) in self.points]

    def rotate_points(self, angle_in_degrees=None, rot_matr=None):
        if angle_in_degrees is None:
            self.points = [rotate_point(x, y , rotator_matrix=rot_matr) for (x, y) in self.points]
        else:
            self.points = [rotate_point(x, y , angle_in_degrees) for (x, y) in self.points]

class SimpleGraphicsFrame(wx.Frame):
    def __init__(self, parent, *args, **kwargs):
        wx.Frame.__init__(self, parent, *args, **kwargs)

        # Attributes
        self.panel = SimpleGraphics(self)

        # Layout
        sizer = wx.BoxSizer(wx.VERTICAL)
        sizer.Add(self.panel, 1, wx.EXPAND)
        self.SetSizer(sizer)

class SimpleGraphApp(wx.App):
    def OnInit(self):
        self.frame = SimpleGraphicsFrame(None,
                                 title="Drawing Shapes",
                                 size=(300, 400))
        self.frame.Show()
        return True

if __name__ == '__main__':
    app = SimpleGraphApp(False)
    app.MainLoop()

Answer 1

您从self.Refresh()和OnKeyArrow个活动中致电OnMotion。在这些方法中更新您的场景数据并设置一些标记，例如self.repaint_needed = True。然后在OnIdle中重新绘制场景，如果self.repaint_needed为真。

现在，您每次收到事件时都会尝试重新绘制窗口。这可能很多。

您要做的是每次都更新场景信息，但只有当wx表示它有一些“空闲时间”时才重新绘制窗口。

如何平滑重绘窗体上的对象（wxPython）

1 个答案: