93

所以我在我的draw方法中使用下面的代码在android地图中绘制这个三角形：

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 是我从字段中获取的坐标。它们基本上是纬度和经度。结果是一个漂亮的三角形，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？

4

8 回答 8

76

好的，我已经做到了。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;

感谢尼古拉斯的提示！

于 2010-08-17T10:58:31.160 回答
44

您可能需要执行以下操作：

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。确保路径的最后一点在第一个点结束，这也很有意义。

请告诉我它是否有效！

于 2010-08-17T09:50:36.107 回答
12

你也可以使用顶点：

private static final int verticesColors[] = {
    Color.LTGRAY, Color.LTGRAY, Color.LTGRAY, 0xFF000000, 0xFF000000, 0xFF000000
};
float verts[] = {
    point1.x, point1.y, point2.x, point2.y, point3.x, point3.y
};
canvas.drawVertices(Canvas.VertexMode.TRIANGLES, verts.length, verts, 0, null, 0, verticesColors,   0, null, 0, 0, new Paint());
于 2010-08-18T07:51:07.547 回答
9

使用@Pavel 的答案作为指导，如果您没有点但有起始 x、y 和高度和宽度，这里是一个辅助方法。也可以绘制倒置/倒置 - 这对我很有用，因为它被用作垂直条形图的末端。

 private void drawTriangle(int x, int y, int width, int height, boolean inverted, Paint paint, Canvas canvas){

        Point p1 = new Point(x,y);
        int pointX = x + width/2;
        int pointY = inverted?  y + height : y - height;

        Point p2 = new Point(pointX,pointY);
        Point p3 = new Point(x+width,y);


        Path path = new Path();
        path.setFillType(Path.FillType.EVEN_ODD);
        path.moveTo(p1.x,p1.y);
        path.lineTo(p2.x,p2.y);
        path.lineTo(p3.x,p3.y);
        path.close();

        canvas.drawPath(path, paint);
    }
于 2016-03-08T17:06:23.323 回答
8

在此处输入图像描述

此函数显示如何从位图创建三角形。也就是说，创建三角形的裁剪图像。试试下面的代码或下载演示示例

 public static Bitmap getTriangleBitmap(Bitmap bitmap, int radius) {
        Bitmap finalBitmap;
        if (bitmap.getWidth() != radius || bitmap.getHeight() != radius)
            finalBitmap = Bitmap.createScaledBitmap(bitmap, radius, radius,
                    false);
        else
            finalBitmap = bitmap;
        Bitmap output = Bitmap.createBitmap(finalBitmap.getWidth(),
                finalBitmap.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(output);

        Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, finalBitmap.getWidth(),
                finalBitmap.getHeight());

        Point point1_draw = new Point(75, 0);
        Point point2_draw = new Point(0, 180);
        Point point3_draw = new Point(180, 180);

        Path path = new Path();
        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.drawARGB(0, 0, 0, 0);
        paint.setColor(Color.parseColor("#BAB399"));
        canvas.drawPath(path, paint);
        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
        canvas.drawBitmap(finalBitmap, rect, rect, paint);

        return output;
    }

上面的函数返回在画布上绘制的三角形图像。阅读更多

于 2017-01-01T10:52:57.457 回答
4 
private void drawArrows(Point[] point, Canvas canvas, Paint paint) {

    float [] points  = new float[8];             
    points[0] = point[0].x;      
    points[1] = point[0].y;      
    points[2] = point[1].x;      
    points[3] = point[1].y;         
    points[4] = point[2].x;      
    points[5] = point[2].y;              
    points[6] = point[0].x;      
    points[7] = point[0].y;

    canvas.drawVertices(VertexMode.TRIANGLES, 8, points, 0, null, 0, null, 0, null, 0, 0, paint);
    Path path = new Path();
    path.moveTo(point[0].x , point[0].y);
    path.lineTo(point[1].x,point[1].y);
    path.lineTo(point[2].x,point[2].y);
    canvas.drawPath(path,paint);

}
于 2012-05-08T11:06:47.670 回答
3

您需要在第一次初始后删除 path.moveTo 。

Path path = new Path();
path.moveTo(point1_returned.x, point1_returned.y);
path.lineTo(point2_returned.x, point2_returned.y);
path.lineTo(point3_returned.x, point3_returned.y);
path.lineTo(point1_returned.x, point1_returned.y);
path.close();
于 2014-12-01T15:45:39.687 回答
2

不要moveTo()在每个之后lineTo()

换句话说，删除moveTo()除第一个之外的所有内容。

说真的，如果我只是复制粘贴 OP 的代码并删除不必要的moveTo()调用，它就可以工作。

没有其他事情需要做。

编辑：我知道 OP 已经发布了他的“最终工作解决方案”，但他没有说明它为什么有效。真正的原因让我很惊讶，所以我觉得有必要添加一个答案。

于 2017-07-14T12:29:07.263 回答