在android中绘制圆圈

Question

如何使用android SDK在两点之间绘制圆圈？

Answer 1

创建一个位图,然后在其画布上绘制,然后将此位图添加到imageview或按钮或任何你想要的.

创建位图:

    Bitmap bmp = Bitmap.createBitmap(width, height, config);

在位图画布上绘制

    Canvas c = new Canvas(bmp);
    c.drawCircle(cx, cy, radius, paint)

设置为imageview

    img.setBackgroundDrawable(new BitmapDrawable(bmp));

Answer 2

您不一定需要创建位图手册.

例如,如果使用SurfaceView,则可以在SurfaceView类中绘制圆形:

public class Circle extends SurfaceView implements SurfaceHolder.Callback {
private Paint paint;

    public void onDraw(Canvas canvas) {
        canvas.drawCircle(x, y, radius, this.paint);
    }
}

然后,您可以将SurfaceView添加到Activity类,如:

public class MovingCircle extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new Circle());
    }

}

我希望这也会对你有所帮助.