Kivy以清晰的背景拍攝截圖

Question

我正在開發一個Kivy應用程序，讓用戶可以在模板上定位圖像和文本標簽。 完成后，將裁剪生成的圖像以適合模板。

我需要清除圖像中的所有空白區域，因為我將打印圖像並且不想浪費墨水。 然而，Kivy用黑色填充所有空白區域。 有沒有辦法讓Kivy的export_to_png（）函數使用透明背景而不是黑色背景？

Answer 1

我可能錯了，但看起來透明的顏色是硬編碼的。

看一下源代碼 ，似乎ClearColor被硬編碼為黑色。

def export_to_png(self, filename, *args):
        '''Saves an image of the widget and its children in png format at the
        specified filename. Works by removing the widget canvas from its
        parent, rendering to an :class:`~kivy.graphics.fbo.Fbo`, and calling
        :meth:`~kivy.graphics.texture.Texture.save`.

        .. note::

            The image includes only this widget and its children. If you want
            to include widgets elsewhere in the tree, you must call
            :meth:`~Widget.export_to_png` from their common parent, or use
            :meth:`~kivy.core.window.WindowBase.screenshot` to capture the whole
            window.

        .. note::

            The image will be saved in png format, you should include the
            extension in your filename.

        .. versionadded:: 1.9.0
        '''

        if self.parent is not None:
            canvas_parent_index = self.parent.canvas.indexof(self.canvas)
            self.parent.canvas.remove(self.canvas)

        fbo = Fbo(size=self.size, with_stencilbuffer=True)

        with fbo:
            ClearColor(0, 0, 0, 1)
            ClearBuffers()
            Scale(1, -1, 1)
            Translate(-self.x, -self.y - self.height, 0)

我想你可以嘗試更新Widget模塊代碼以接受一個參數來設置ClearColor 。