在画布上绘制2个圆形

Question

我尝试像这样画两个圆圈： 这是我的做法：

Bitmap bmp = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_4444);

Canvas c = new Canvas(bmp);

RectF rect = new RectF(0,0,width,width);
Paint paint = new Paint();
drawCircles(paint, c, width, height, width);
ImageView img = (ImageView) findViewById(R.id.imageView1);
img.setImageBitmap(bmp);
img.setScaleType(ScaleType.FIT_CENTER);

以下是我的drawCircles()方法：

private void drawCircles(Paint paint, Canvas c, int width, int height, int radius) {
        paint.setARGB(255, 255 , 10, 21);
        paint.setStrokeWidth(10);
        paint.setAntiAlias(true);
        paint.setStrokeCap(Paint.Cap.BUTT);
        paint.setStyle(Paint.Style.STROKE);
        if(width < height && radius == 0){
            radius = width/2;
            height = width;
        } else if (radius == 0){
            radius = height/2;
            width = height;
        }
        Paint paint2 = new Paint();
        paint2.setARGB(255, 255 , 10, 21);
        paint2.setStrokeWidth(10);
        paint2.setAntiAlias(true);
        paint2.setStrokeCap(Paint.Cap.BUTT);
        paint2.setStyle(Paint.Style.STROKE);
        c.drawCircle(width/2, height/2, radius-10, paint);
        c.drawCircle(width/2, height/2, 50, paint2);
}

我不知道为什么我只得到了一个圆，是小圆（用paint2绘制的）。 可能的原因是什么？

- dziwna

---

在调试模式下检查您的半径值。可能是因为您在绘制时减去的值小于10。 - Raj

@Raj 我已经检查过了，半径没问题。 - dziwna

然后检查半径值。它可能是60。为了测试，将第一个drawCircle中的半径硬编码到大约30左右，并进行检查。c.drawCircle（width/2，height/2，30，paint）； - Raj

Answer 1

尝试使用这段代码。希望它能有所帮助 :)

public class SimpleCircleActivity extends Activity
{

       private CircleDemoView circledemoView ;

       public void onCreate(Bundle savedInstanceState)
       { 
        super.onCreate(savedInstanceState);

        circledemoView =new CircleDemoView(this);
        setContentView(circledemoView);

       }


       private class CircleDemoView extends View
       {
         public CircleDemoView(Context context)
         {
             super(context);
         }

         @Override
         protected void onDraw(Canvas canvas) 
         {

             super.onDraw(canvas);
             Paint p = new Paint();
             p.setColor(Color.RED);
             DashPathEffect dashPath = new DashPathEffect(new float[]{5,5}, (float)1.0);

             p.setPathEffect(dashPath);
             p.setStyle(Style.STROKE);


             for (int i = 0; i < 2; i ++) {
                 canvas.drawCircle(200, 200, 50+(i*40), p);
             }


             invalidate();

     }
     }

}

- AndroidLearner