Android--SVG打造可交互式中国地图

aruba

发布于 2020-07-03 11:18:42

1.6K0

发布于 2020-07-03 11:18:42

文章被收录于专栏：android技术

效果如下：

首先我们需要一张svg的中国地图图片

第一步：将svg转换为安卓中的vector（利用插件或网站http://inloop.github.io/svg2android/）

第二步，自定义View解析xml，将所有Path标签转换为我们安卓的Path对象

    private Thread ParseThread = new Thread(new Runnable() {
        @Override
        public void run() {
            InputStream inputStream = getContext().getResources().openRawResource(rawId);
            try {
                DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
                Document document = builder.parse(inputStream);
                Element root = document.getDocumentElement();//获取根节点
                NodeList nodeList = root.getElementsByTagName("path");

                provinceItems = new ArrayList<>(nodeList.getLength());
                for (int i = 0; i < nodeList.getLength(); i++) {
                    Element element = (Element) nodeList.item(i);//path节点
                    //解析pathData属性
                    ProvinceItem provinceItem = new ProvinceItem();
                    provinceItem.setPath(PathParser.createPathFromPathData(element.getAttribute("android:pathData")));
                    provinceItems.add(provinceItem);
                }

                postInvalidate();
            } catch (ParserConfigurationException | IOException | SAXException e) {
                e.printStackTrace();
            }
        }
    });

第三步，在onDraw方法中画出path集合

    @Override
    protected void onDraw(Canvas canvas) {
        canvas.save();
        canvas.scale(scale, scale);
        for (ProvinceItem provinceItem : provinceItems) {
            if (selectItem != provinceItem)
                provinceItem.drawPath(canvas, mPaint, false);
        }

        if (selectItem != null) selectItem.drawPath(canvas, mPaint, true);
        canvas.restore();
    }

第四步，改写onTouchEvent方法，判断是否触摸到省份

  @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                return true;
            case MotionEvent.ACTION_UP: {
                ProvinceItem temp = null;
                for (ProvinceItem provinceItem : provinceItems) {
                    if (provinceItem.isOnTouch(event.getX() / scale, event.getY() / scale)) {
                        temp = provinceItem;
                        break;
                    }
                }

                if (temp != null) {
                    selectItem = temp;
                    postInvalidate();
                }
            }
        }
        return super.onTouchEvent(event);
    }

利用Region的contains方法判断抬起坐标是否在path范围内

    public boolean isOnTouch(float x, float y) {
        Region region = new Region();
        RectF rect = new RectF();
        path.computeBounds(rect, true);
        region.setPath(path, new Region((int) rect.left, (int) rect.top, (int) rect.right, (int) rect.bottom));

        return region.contains((int) x, (int) y);
    }