如何在 WxPython GUI 中拖动图像对象?

How To drag an image object in WxPython GUI?

在下面的代码中,我有透明形状的图像 window 和其中的图像,我想通过鼠标移动图像(螺旋照片)。我为那个螺丝图像写了一个绑定函数,但它没有移动?可能是什么问题?

可以看出我添加了图像和绑定功能。是不是逻辑有问题?

 import wx
from wx import *
import wx.lib.statbmp as sb
from io import StringIO


# Create a .png image with something drawn on a white background
# and put the path to it here.
IMAGE_PATH = './wood.png'


class ShapedFrame(wx.Frame):
    def __init__(self):
        wx.Frame.__init__(self, None, -1, "Shaped Window",
            style = wx.FRAME_SHAPED | wx.SIMPLE_BORDER | wx.STAY_ON_TOP)
        self.hasShape = False
        self.delta = wx.Point(0,0)

        # Load the image
        image = wx.Image(IMAGE_PATH, wx.BITMAP_TYPE_PNG)
        image.SetMaskColour(255,255,255)
        image.SetMask(True)            
        self.bmp = wx.Bitmap(image)

        self.SetClientSize((self.bmp.GetWidth(), self.bmp.GetHeight()))
        dc = wx.ClientDC(self)
        dc.DrawBitmap(self.bmp, 0,0, True)
        self.SetWindowShape()

        self.Bind(wx.EVT_RIGHT_UP, self.OnExit)
        self.Bind(wx.EVT_PAINT, self.OnPaint)
        self.Bind(wx.EVT_WINDOW_CREATE, self.SetWindowShape)

        panel = MyPanel(parent=self)

    def SetWindowShape(self, evt=None):
        r = wx.Region(self.bmp)
        self.hasShape = self.SetShape(r)

    def OnDoubleClick(self, evt):
        if self.hasShape:
            self.SetShape(wx.Region())
            self.hasShape = False
        else:
            self.SetWindowShape()

    def OnPaint(self, evt):
        dc = wx.PaintDC(self)
        dc.DrawBitmap(self.bmp, 0,0, True)

    def OnExit(self, evt):
        self.Close()

    def OnLeftDown(self, evt):
        self.CaptureMouse()
        pos = self.ClientToScreen(evt.GetPosition())
        origin = self.GetPosition()
        self.delta = wx.Point(pos.x - origin.x, pos.y - origin.y)

    def OnMouseMove(self, evt):
        if evt.Dragging() and evt.LeftIsDown():
            pos = self.ClientToScreen(evt.GetPosition())
            newPos = (pos.x - self.delta.x, pos.y - self.delta.y)
            self.Move(newPos)

    def OnLeftUp(self, evt):
        if self.HasCapture():
            self.ReleaseMouse()



class MyPanel(wx.Panel):
    # A panel is a window on which controls are placed. (e.g. buttons and text boxes)
    # wx.Panel class is usually put inside a wxFrame object. This class is also inherited from wxWindow class.
    def __init__(self,parent):
        super().__init__(parent=parent)
        MyImage(self)



class MyImage(wx.StaticBitmap):

    def __init__(self,parent):
        super().__init__(parent=parent)
        
        jpg1 = wx.Image('./Images/screwsmall.png', wx.BITMAP_TYPE_ANY).ConvertToBitmap()
        # bitmap upper left corner is in the position tuple (x, y) = (5, 5)
        self.myImage = wx.StaticBitmap(parent, -1, jpg1, (10 + jpg1.GetWidth(), 5), (jpg1.GetWidth(), jpg1.GetHeight()))
        self.myImage.Bind(wx.EVT_MOTION, self.OnMouseMove)
        self.myImage.Bind(wx.EVT_LEFT_DOWN, self.OnLeftDown)

    def OnMouseMove(self, evt):
        if evt.Dragging() and evt.LeftIsDown():
            pos = self.ClientToScreen(evt.GetPosition())
            newPos = (pos.x - self.delta.x, pos.y - self.delta.y)
            self.Move(newPos)

    def OnLeftUp(self, evt):
        if self.HasCapture():
            self.ReleaseMouse()

    def OnLeftDown(self, evt):
        self.CaptureMouse()
        pos = self.ClientToScreen(evt.GetPosition())
        origin = self.GetPosition()
        self.delta = wx.Point(pos.x - origin.x, pos.y - origin.y)


if __name__ == '__main__':
    app = wx.App()

    ShapedFrame().Show()
    app.MainLoop()

我的代码的可视化输出你可以在本地目录中使用不同的形状。要为 3.x 安装 wxpython,你可以检查这个 link https://extras.wxpython.org/wxPython4/extras/linux/gtk3/ubuntu-16.04/ 下载你的 ubuntu 版本并使用 pip install 命令。

我要发表我的答案了。在@RolfofSaxony 评论中可以看到,WXPYTHON tar 文件中有一个拖动图像演示。在那个 DragImage.py 文件中有两个不同的 classes 做拖动工作。我修改了那些函数并写了我自己的两个class。您可以在代码中将这些 classes 作为组件使用。我的代码正在运行并经过测试。

class DragShape:
    def __init__(self, bmp):
        self.bmp = bmp
        self.pos = (0,0)
        self.shown = True
        self.text = None
        self.fullscreen = False

    def HitTest(self, pt):
        rect = self.GetRect()
        return rect.Contains(pt)

    def GetRect(self):
        return wx.Rect(self.pos[0], self.pos[1],
                      self.bmp.GetWidth(), self.bmp.GetHeight())

    def Draw(self, dc, op = wx.COPY):
        if self.bmp.IsOk():
            memDC = wx.MemoryDC()
            memDC.SelectObject(self.bmp)

            dc.Blit(self.pos[0], self.pos[1],
                    self.bmp.GetWidth(), self.bmp.GetHeight(),
                    memDC, 0, 0, op, True)

            return True
        else:
            return False



#----------------------------------------------------------------------

class DragCanvas(wx.ScrolledWindow):
    def __init__(self, parent, ID):
        wx.ScrolledWindow.__init__(self, parent, ID)
        self.shapes = []
        self.dragImage = None
        self.dragShape = None
        self.hiliteShape = None

        self.SetCursor(wx.Cursor(wx.CURSOR_ARROW))

        bmp = images.TheKid.GetBitmap()
        shape = DragShape(bmp)
        shape.pos = (200, 5)
        self.shapes.append(shape)

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


    # We're not doing anything here, but you might have reason to.
    # for example, if you were dragging something, you might elect to
    # 'drop it' when the cursor left the window.
    def OnLeaveWindow(self, evt):
        pass




    # Go through our list of shapes and draw them in whatever place they are.
    def DrawShapes(self, dc):
        for shape in self.shapes:
            if shape.shown:
                shape.Draw(dc)

    # This is actually a sophisticated 'hit test', but in this
    # case we're also determining which shape, if any, was 'hit'.
    def FindShape(self, pt):
        for shape in self.shapes:
            if shape.HitTest(pt):
                return shape
        return None


    # Fired whenever a paint event occurs
    def OnPaint(self, evt):
        dc = wx.PaintDC(self)
        self.PrepareDC(dc)
        self.DrawShapes(dc)
        # print('OnPaint')

    # Left mouse button is down.
    def OnLeftDown(self, evt):
        # Did the mouse go down on one of our shapes?
        shape = self.FindShape(evt.GetPosition())

        # If a shape was 'hit', then set that as the shape we're going to
        # drag around. Get our start position. Dragging has not yet started.
        # That will happen once the mouse moves, OR the mouse is released.
        if shape:
            self.dragShape = shape
            self.dragStartPos = evt.GetPosition()

    # Left mouse button up.
    def OnLeftUp(self, evt):
        if not self.dragImage or not self.dragShape:
            self.dragImage = None
            self.dragShape = None
            return

        # Hide the image, end dragging, and nuke out the drag image.
        self.dragImage.Hide()
        self.dragImage.EndDrag()
        self.dragImage = None

        if self.hiliteShape:
            self.RefreshRect(self.hiliteShape.GetRect())
            self.hiliteShape = None

        # reposition and draw the shape

        # Note by jmg 11/28/03
        # Here's the original:
        #
        # self.dragShape.pos = self.dragShape.pos + evt.GetPosition() - self.dragStartPos
        #
        # So if there are any problems associated with this, use that as
        # a starting place in your investigation. I've tried to simulate the
        # wx.Point __add__ method here -- it won't work for tuples as we
        # have now from the various methods
        #
        # There must be a better way to do this :-)
        #

        self.dragShape.pos = (
            self.dragShape.pos[0] + evt.GetPosition()[0] - self.dragStartPos[0],
            self.dragShape.pos[1] + evt.GetPosition()[1] - self.dragStartPos[1]
            )

        self.dragShape.shown = True
        self.RefreshRect(self.dragShape.GetRect())
        self.dragShape = None


    # The mouse is moving
    def OnMotion(self, evt):
        # Ignore mouse movement if we're not dragging.
        if not self.dragShape or not evt.Dragging() or not evt.LeftIsDown():
            return

        # if we have a shape, but haven't started dragging yet
        if self.dragShape and not self.dragImage:

            # only start the drag after having moved a couple pixels
            tolerance = 2
            pt = evt.GetPosition()
            dx = abs(pt.x - self.dragStartPos.x)
            dy = abs(pt.y - self.dragStartPos.y)
            if dx <= tolerance and dy <= tolerance:
                return

            # refresh the area of the window where the shape was so it
            # will get erased.
            self.dragShape.shown = False
            self.RefreshRect(self.dragShape.GetRect(), True)
            self.Update()

            item = self.dragShape.text if self.dragShape.text else self.dragShape.bmp
            self.dragImage = wx.DragImage(item,
                                         wx.Cursor(wx.CURSOR_HAND))

            hotspot = self.dragStartPos - self.dragShape.pos
            self.dragImage.BeginDrag(hotspot, self, self.dragShape.fullscreen)

            self.dragImage.Move(pt)
            self.dragImage.Show()


        # if we have shape and image then move it, posibly highlighting another shape.
        elif self.dragShape and self.dragImage:
            onShape = self.FindShape(evt.GetPosition())
            unhiliteOld = False
            hiliteNew = False

            # figure out what to hilite and what to unhilite
            if self.hiliteShape:
                if onShape is None or self.hiliteShape is not onShape:
                    unhiliteOld = True

            if onShape and onShape is not self.hiliteShape and onShape.shown:
                hiliteNew = True

            # if needed, hide the drag image so we can update the window
            if unhiliteOld or hiliteNew:
                self.dragImage.Hide()

            if unhiliteOld:
                dc = wx.ClientDC(self)
                self.hiliteShape.Draw(dc)
                self.hiliteShape = None

            if hiliteNew:
                dc = wx.ClientDC(self)
                self.hiliteShape = onShape
                self.hiliteShape.Draw(dc, wx.INVERT)

            # now move it and show it again if needed
            self.dragImage.Move(evt.GetPosition())
            if unhiliteOld or hiliteNew:
                self.dragImage.Show()