使用动画在画布上绘制圆

Question

我需要使用动画创建一个圆。

我需要将持续时间设置为2000，直到我的圈子以360度结束。

课程内容

End if

活动内容

Option Explicit

问题是我的圆没有在圆的尽头结束而停在中间的某个地方。这条线在我的圆的尽头没有完成...

[！[Img] [1]] [1]

f

Answer 1

您可以尝试以下代码，效果是这样的

课程内容

class MyCustomView:View
    {
        private int animValue;
        private int strokeWidth = 15;
        //private int i = 0;

        public MyCustomView(Context context) :
            base(context)
        {
        }

        public MyCustomView(Context context, IAttributeSet attrs) :
             base(context, attrs)
        {
            animValue = 0;
        }

        public MyCustomView(Context context, IAttributeSet attrs, int defStyle) :
            base(context, attrs, defStyle)
        {
        }

        protected override void OnDraw(Canvas canvas)
        {
            base.OnDraw(canvas);
            Paint paint = new Paint();
            paint.SetStyle(Paint.Style.Stroke);
            paint.StrokeWidth = (strokeWidth);

            RectF rectF = new RectF();
            rectF.Set(strokeWidth, strokeWidth, Width - strokeWidth, Width - strokeWidth);
            paint.Color = (Color.Gray);
            canvas.DrawArc(rectF, 0, 360, false, paint);
            paint.Color = (Color.Blue);
            canvas.DrawArc(rectF, 0, animValue, false, paint);
        }

        public void setValue(int animatedValue)
        {
            animValue = animatedValue;
            Invalidate();
        }
    }

活动内容

   protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        // Set our view from the "main" layout resource
        SetContentView(Resource.Layout.activity_main);
        var circleView = FindViewById<MyCustomView>(Resource.Id.circleView);
        ValueAnimator valueAnimator = ValueAnimator.OfInt(0, 360);
        valueAnimator.SetDuration(2000);
        valueAnimator.AddUpdateListener(new AnimatorUpdateListener(this, circleView));
        valueAnimator.Start();
    }

    private class AnimatorUpdateListener : Java.Lang.Object, ValueAnimator.IAnimatorUpdateListener
    {

        private MainActivity mainActivity;
        private MyCustomView circleView;

        public AnimatorUpdateListener(MainActivity mainActivity, MyCustomView circleView)
        {
            this.mainActivity = mainActivity;
            this.circleView = circleView;
        }

        void ValueAnimator.IAnimatorUpdateListener.OnAnimationUpdate(ValueAnimator animation)
        {
               circleView.setValue((int)animation.AnimatedValue);

        }
    }