为drawLine使用rotateAnimation

Question

我有一条线，我用"canvas.drawLine( 250,400,250,200，p3 )“画它，我想用rotateAnimation旋转它，有没有办法呢？当我试图将drawLine(...)放在一个方法中时，它没有被编译...

import android.widget.Toast;

class Circles<Graphics> extends View
{
public Circles(Context context)
  {
      super(context);    
  }

  public void onDraw(final Canvas canvas) 
  {
      super.onDraw(canvas);
      //2 Circels
      Paint p1 = new Paint();
      p1.setColor(Color.BLUE);
      p1.setStyle(Style.STROKE);
       Paint p2 = new Paint();
      p2.setColor(Color.RED);
      p2.setStyle(Style.FILL);
      canvas.drawCircle(250, 400, 250, p1);
      canvas.drawCircle(250, 400, 20, p2);
    //  invalidate();

      // Seconds
      final Paint p3 = new Paint();
      p3.setColor(Color.RED);
      p3.setStyle(Style.FILL);
      int b1 ; 

      Runnable seconds = new Runnable() {
            public void run() {
         try {
         int seconds = 0;
     RotateAnimation rotateAnimation = new RotateAnimation(
                   (seconds - 1) * 6, seconds * 6,
                   Animation.RELATIVE_TO_SELF, 0.5f,
                   Animation.RELATIVE_TO_SELF, 0.5f);
         rotateAnimation.setInterpolator(new LinearInterpolator());
         rotateAnimation.setDuration(1000);
         rotateAnimation.setFillAfter(true);

    // now rotate this   canvas.drawLine(250, 400 , 250 , 200, p3 ) ; 


         } catch (Exception e) {

          }
  }

      };
  } 

Answer 1

如果你想使用动画来绘制圆线，请使用我的代码。有一个动画，它只给你提供旋转动画的插值时间，所以你可以简单地刷新toAngleValue并刷新绘图状态，以平滑你的线条绘制。

/**
 * Created by GIGAMOLE on 17.06.2015.
 */
public class CustomView extends View {

    public CustomView(Context context) {
        this(context, null);
    }

    public CustomView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public CustomView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);

        startAnimation(new CustomAnimation(fromAngleValue, toAngleValue));
        setWillNotDraw(false);
    }

    //Out values for angle circle
    private float fromAngleValue = 0f;
    private float toAngleValue = 360f;
    private float currentAngleValue;

    //Paint
    private Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG) {
        {
            setDither(true);
            setColor(Color.RED);
            setStrokeWidth(5);
            setStyle(Style.STROKE);
        }
    };

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        //Always draw arc and invalidate it in animation
        canvas.drawArc(
                new RectF(
                        50,
                        50,
                        getWidth() - 50,
                        getHeight() - 50
                ),
                fromAngleValue,
                currentAngleValue,
                false,
                paint
        );
    }

    private class CustomAnimation extends RotateAnimation {

        public CustomAnimation(Context context, AttributeSet attrs) {
            super(context, attrs);
        }

        public CustomAnimation(float fromDegrees, float toDegrees) {
            super(fromDegrees, toDegrees);

            setDuration(3000);
            setFillAfter(true);
        }

        public CustomAnimation(float fromDegrees, float toDegrees, float pivotX, float pivotY) {
            super(fromDegrees, toDegrees, pivotX, pivotY);
        }

        @Override
        protected void applyTransformation(float interpolatedTime, Transformation t) {
            currentAngleValue = interpolatedTime * toAngleValue;
            invalidate();

            //Change current value relative to animation
        }
    }
}

Answer 2

你也可以使用esiest方法，它只在失效后增加值，但没有像混凝土持续时间和任何类型的内插器这样的功能。

/**
 * Created by GIGAMOLE on 17.06.2015.
 */
public class CustomView extends View {

    public CustomView(Context context) {
        this(context, null);
    }

    public CustomView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public CustomView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);

        setWillNotDraw(false);
    }

    //Out values for angle circle
    private float fromAngleValue = 0f;
    private float toAngleValue = 360f;
    private float currentAngleValue;

    //Paint
    private Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG) {
        {
            setDither(true);
            setColor(Color.RED);
            setStrokeWidth(5);
            setStyle(Style.STROKE);
        }
    };

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        //Always draw arc and invalidate it in animation

        canvas.drawArc(
                new RectF(
                        50,
                        50,
                        getWidth() - 50,
                        getHeight() - 50
                ),
                fromAngleValue,
                currentAngleValue,
                false,
                paint
        );

        if (currentAngleValue <= toAngleValue) {
            currentAngleValue++;
            postInvalidateDelayed(1);
        }
    }

}