如何通过一个可从Java(而不是Xml)绘制的图形来创建一个圆?

可以使用ShapeDrawables:

ShapeDrawable shapeDrawable = new ShapeDrawable(new OvalShape());
shapeDrawable.setIntrinsicHeight(height);
shapeDrawable.setIntrinsicWidth(width);

我终于找到了一个简单的方法来制作一个椭圆形的可拉伸:

    GradientDrawable gd = new GradientDrawable();
    int fillColor = Color.parseColor("FF0000");
    gd.setColor(fillColor);
    int strokeWidth = 2; // px not dp
    int strokeColor = Color.parseColor("#000000");
    gd.setStroke(strokeWidth, strokeColor);
    gd.setShape(GradientDrawable.OVAL);