自定义圆:
public class Yuan extends View{ public static final float RADIUS=50f; private Point currentPoint; private circleColor currentColor; private Paint paint=new Paint(); public Yuan(Context context) { super(context); } public Yuan(Context context, @Nullable AttributeSet attrs) { super(context, attrs); } public Yuan(Context context, @Nullable AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); } //确定控件的位置和颜色 @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); if (currentPoint==null){ currentColor=new circleColor(Color.BLUE); paint.setColor(currentColor.getColor()); currentPoint=new Point(RADIUS,RADIUS); canvas.drawCircle(currentPoint.getX(),currentPoint.getY(),RADIUS,paint); starAnim(); }else { paint.setColor(currentColor.getColor()); canvas.drawCircle(currentPoint.getX(),currentPoint.getY(),RADIUS,paint); } } //开始设计动画的效果 private void starAnim() { Point startPoint=new Point(RADIUS,RADIUS); Point endPoint=new Point(getWidth()-RADIUS,getHeight()-RADIUS); final ValueAnimator value=ValueAnimator.ofObject(new PointEvaluator(),startPoint,endPoint); value.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { if (animation!=null){ currentPoint=(Point)animation.getAnimatedValue(); invalidate(); } } }); } //自己定义的模式里面计算开始到结束,原点和颜色的差值 class PointEvaluator implements TypeEvaluator { @Override public Object evaluate(float fraction, Object startValue, Object endValue) { Point startPoin=(Point)startValue; Point endPoin=(Point)endValue; float x = startPoin.getX() + fraction * (endPoin.getX() - startPoin.getX()); float y = startPoin.getY() + fraction * (endPoin.getY() - startPoin.getY()); return new Point(x,y); } } class ColorEvalustor implements TypeEvaluator{ int count; @Override public Object evaluate(float fraction, Object startValue, Object endValue) { circleColor startColor=(circleColor)startValue; circleColor endColor=(circleColor)endValue; int alpha=(int)(Color.alpha(startColor.getColor())+fraction*(Color.alpha(endColor.getColor())-Color.alpha(startColor.getColor()))); int red=(int)(Color.red(startColor.getColor())+fraction*(Color.red(endColor.getColor())-Color.red(startColor.getColor()))); int green=(int)(Color.green(startColor.getColor())+fraction*(Color.green(endColor.getColor())-Color.green(endColor.getColor()))); int blue=(int)(Color.blue(startColor.getColor())+fraction*(Color.blue(endColor.getColor())-Color.blue(endColor.getColor()))); return new circleColor(Color.argb(alpha,red,green,blue)); } } public class circleColor{ private int color; @Override public String toString() { return "circleColor{" + "color=" + color + '}'; } public int getColor() { return color; } public void setColor(int color) { this.color = color; } public circleColor(int color) { this.color = color; } } public class Point { private float x; private float y; public Point(float x, float y) { this.x = x; this.y = y; } @Override public String toString() { return "Point{" + "x=" + x + ", y=" + y + '}'; } public float getX() { return x; } public void setX(float x) { this.x = x; } public float getY() { return y; } public void setY(float y) { this.y = y; } } }
布局:activity_main.xml
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.bwei.yuekao.MainActivity"> <com.bwei.yuekao.Yuan android:id="@+id/yuan" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </RelativeLayout>
MainActivity:
public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); final Yuan yuan= (Yuan) findViewById(R.id.yuan); ValueAnimator valueAnimator=new ValueAnimator(); valueAnimator.setDuration(5000); valueAnimator.setObjectValues(new PointF(0,0)); valueAnimator.setInterpolator(new LinearInterpolator()); valueAnimator.setEvaluator(new TypeEvaluator<PointF>() { @Override public PointF evaluate(float v, PointF pointF, PointF t1) { PointF point=new PointF(); point.x=200*v*3; point.y=0.5f*200*(v*3)*(v*3); return point; } }); valueAnimator.start(); valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator valueAnimator) { PointF point= (PointF) valueAnimator.getAnimatedValue(); yuan.setX(point.x); yuan.setY(point.y); } }); //判断动画是否结束 valueAnimator.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationEnd(Animator animation) { super.onAnimationEnd(animation); //动画结束之后的逻辑 Intent intent=new Intent(MainActivity.this,TwoActivity.class); startActivity(intent); finish(); } }); } }