Question

我需要在自定义视图上用给定多边形的区域填充颜色。我找不到解决该问题的方法。

实际上我只能画出连接这些点的线，但是我不确定如何填充它们所包围的区域。

我用来画线的以下代码：


for (Path p : paths) {
                Paint color = p.getColor();
                float strokeW = color.getStrokeWidth();
                color.setStrokeWidth(pthStrokeWdth);

                List<Point> currentPath = p.getCoordinateList();
                for (int i = 1; i < currentPath.size(); i++) {
                    float startX = currentPath.get(i - 1).x;
                    float startY = currentPath.get(i - 1).y;
                    float endX = currentPath.get(i).x;
                    float endY = currentPath.get(i).y;
                    canvas.drawLine((startX * cellWidth) + xOffset + halfCellWidth, (startY * cellHeight) + yOffset + halfCellHeight,
                            (endX * cellWidth) + xOffset + halfCellWidth, (endY * cellHeight) + yOffset + halfCellHeight, color);

                }
                color.setStrokeWidth(originalStrokeWidth);
 }

上面的绘制线在每个点之间形成了形状多样的多边形。请参见下面的屏幕截图。

所以我想像下面那样填充多边形内部的区域：

感谢您的时间。

Answer 1

您需要将Paint.Style设置为FILL或FILL_AND_STROKE

paint.setStyle(Paint.Style.FILL);

编辑：

    Paint color = p.getColor();
    float strokeW = color.getStrokeWidth();
    color.setStrokeWidth(pthStrokeWdth);
    color.setStyle(Paint.Style.FILL);

    List<Point> currentPath = p.getCoordinateList();
    //for each path we want to draw a line which consist of 4 points
    float[] points = new float[currentPath.size() * 4];
    int count = 0;
    for (int i = 1; i < currentPath.size(); i++) {
        float startX = currentPath.get(i - 1).x;
        float startY = currentPath.get(i - 1).y;
        float endX = currentPath.get(i).x;
        float endY = currentPath.get(i).y;
        points[count++] = (startX * cellWidth) + xOffset + halfCellWidth;
        points[count++] = (startY * cellHeight) + yOffset + halfCellHeight;
        points[count++] = (endX * cellWidth) + xOffset + halfCellWidth;
        points[count++] = (endY * cellHeight) + yOffset + halfCellHeight, color;
    }
    canvas.drawLines(points, color);

如何在画布上绘制填充的多边形

1 个答案: