我创建了一个自定义视图类，用于绘制饼图并为其设置动画。首先，我让类扩展了drawable，然后将drawable应用于视图，它工作正常。我改变了它，所以现在类扩展了相对布局，我可以在xml布局中使用它。方法animateDraw（）是一个值动画师，应该使触发ondraw（）的视图无效，但是从不触发绘制
public class PieView extends RelativeLayout {
public PieView(Context context) {
super(context);
}
public PieView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public PieView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
private HashMap<Integer, Integer> mValues = new HashMap<Integer, Integer>();
private Paint paint;
private float totalArcElapsed;
public boolean animating;
private float dataSum = 0;
public void setValues(HashMap<Integer, Integer> values) {
this.paint = new Paint();
paint.setAntiAlias(true);
paint.setStyle(Paint.Style.FILL);
for (Map.Entry<Integer, Integer> entry : mValues.entrySet()) {
Integer key = entry.getKey();
dataSum += (float) key;
}
}
@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
Log.d(MyApp.TAG, "on draw");
super.onDraw(canvas);
}
@Override
public void draw(Canvas canvas) {
super.draw(canvas);
Log.d(MyApp.TAG, "draw");
float startAngle = 0;
RectF rectBounds = new RectF(getLeft(), getTop(), getRight(), getBottom());
for (Map.Entry<Integer, Integer> entry : mValues.entrySet()) {
float sliceValue = (float) entry.getKey();
Integer colorRes = entry.getValue();
paint.setColor(colorRes);
float angleSweep = 360 * (sliceValue / dataSum);
if ((startAngle + angleSweep) < totalArcElapsed) {
canvas.drawArc(rectBounds, startAngle, angleSweep, true, paint);
}
else {
float portion = angleSweep - ((startAngle + angleSweep) - totalArcElapsed);
canvas.drawArc(rectBounds, startAngle, portion, true, paint);
break;
}
startAngle += angleSweep;
}
}
public void animateDraw() {
ValueAnimator animation = ValueAnimator.ofInt(0, 360);
animation.setDuration(2000);
animation.addUpdateListener(new AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
float fraction = animation.getAnimatedFraction();
int value = (Integer) animation.getAnimatedValue();
totalArcElapsed = value;
Log.d(MyApp.TAG, totalArcElapsed + " ");
invalidate();
}
});
animation.addListener(new AnimatorListener() {
@Override
public void onAnimationStart(Animator animation) {
animating = true;
}
@Override
public void onAnimationRepeat(Animator animation) {
// TODO Auto-generated method stub
}
@Override
public void onAnimationEnd(Animator animation) {
animating = false;
}
@Override
public void onAnimationCancel(Animator animation) {
}
});
animation.start();
}
}