如何在安卓画布中绘制填充三角形？

google-maps android java android-canvas

2022-08-31 10:56:42

因此，我正在使用以下绘制方法中的代码在Android地图中绘制此三角形：

paint.setARGB(255, 153, 29, 29);
paint.setStyle(Paint.Style.FILL_AND_STROKE);
paint.setAntiAlias(true);

Path path = new Path();
path.moveTo(point1_returned.x, point1_returned.y);
path.lineTo(point2_returned.x, point2_returned.y);
path.moveTo(point2_returned.x, point2_returned.y);
path.lineTo(point3_returned.x, point3_returned.y);
path.moveTo(point3_returned.x, point3_returned.y);
path.lineTo(point1_returned.x, point1_returned.y);
path.close();

canvas.drawPath(path, paint);

pointX_returned是我从田野中得到的坐标。它们基本上是纬度和经度。结果是一个不错的三角形，但内部是空的，因此我可以看到地图。有没有办法以某种方式填充它？

答案 1

好的，我做到了。我正在共享此代码，以防其他人需要它：

super.draw(canvas, mapView, true);

Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);

paint.setStrokeWidth(2);
paint.setColor(android.graphics.Color.RED);     
paint.setStyle(Paint.Style.FILL_AND_STROKE);
paint.setAntiAlias(true);

Point point1_draw = new Point();        
Point point2_draw = new Point();    
Point point3_draw = new Point();

mapView.getProjection().toPixels(point1, point1_draw);
mapView.getProjection().toPixels(point2, point2_draw);
mapView.getProjection().toPixels(point3, point3_draw);

Path path = new Path();
path.setFillType(Path.FillType.EVEN_ODD);
path.moveTo(point1_draw.x,point1_draw.y);
path.lineTo(point2_draw.x,point2_draw.y);
path.lineTo(point3_draw.x,point3_draw.y);
path.lineTo(point1_draw.x,point1_draw.y);
path.close();

canvas.drawPath(path, paint);

//canvas.drawLine(point1_draw.x,point1_draw.y,point2_draw.x,point2_draw.y, paint);

return true;

谢谢你的提示尼古拉斯！

答案 2

您可能需要执行如下操作：

Paint red = new Paint();

red.setColor(android.graphics.Color.RED);
red.setStyle(Paint.Style.FILL);

并将此颜色用于您的路径，而不是您的ARGB。确保路径的最后一个点在第一个点上结束，这也是有道理的。

请告诉我它是否有效！