java - 如何在不填充的情况下在位图上绘制圆圈？

Question

我正在位图上绘制一个圆圈并将该位图设置为 ImageView。圆圈绘制正确，但我不希望它是实心圆圈，有什么办法可以使填充区域透明吗？我正在使用以下代码

Bitmap bmp = RasterImageConverter.convertToBitmap(_loadedImage, ConvertToImageOptions.NONE.getValue());
Canvas c = new Canvas(bmp);
c = new Canvas(bmp);
myimgview.draw(c);
Paint p = new Paint();
p.setColor(Color.RED);
float x=(float) circleX;
float y=(float) circleY;
float Tx=(float) textX;
float Ty=(float)textY;
// c.drawLine(x, y, xend, yend, p);
c.drawCircle(300, 300, 200, p);
c.drawText(myText, Tx, Ty, p);
myimgview.setImageBitmap(bmp);

Answer 1

您需要通知绘画您使用的不是填充样式，而是描边样式。

The default is FILL

The Style specifies if the primitive being drawn is filled, stroked, or both (in the same color). The default is FILL.

所以你的代码必须是:

Paint p = new Paint();
p.setStyle(Paint.Style.STROKE);

Here解释了不同风格之间的差异。

STROKE Geometry and text drawn with this style will be stroked, respecting the stroke-related fields on the paint.

FILL Geometry and text drawn with this style will be filled, ignoring all stroke-related settings in the paint.

FILL_AND_STROKE Geometry and text drawn with this style will be both filled and stroked at the same time, respecting the stroke-related fields on the paint.