Question

我想在android studio中为android应用程序创建一个动态雷达，看起来像这样：

http://jsbin.com/AMag/2/edit?html,css,output

我怎么能这样做？

Answer 1

这是一个起点。像这样创建一个自定义视图并将其添加到LinearLayout。

class RadarBlip {
    float x;
    float y;

    public void setX (float x) {
        this.x = x;
    }

    public Float getX() {
        return x;
    }
    ....
}

private class RadarView extends View {

    List<RadarBlip> mRadarBlips;

    public TimerViewContentView(Context context, List<RadarBlip> radarBlips, currentRadarAngle) {
        super(context);
        setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
        mRadarBlips = radarBlips;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        for(int i = 0; i < mRadarBlips.size(); i++) {
            blipPaint.setAlpha(...do geometry...);
            canvas.drawCircle(mRadarBlips.get(i).getX(), mRadarBlips.get(i).getY(), radius, blipPaint);
        }
        canvas.drawArc(oval, currentRadarAngle, currentRadarAngle - 10, false, radarPaint);
    }
}

然后，您想要在Timer中调用视图。类似的东西：

    new CountDownTimer(timeRemaining, 15) {
        public void onTick(long millisUntilFinished) {
            float radarAngle = ((long)millisUntilFinished)%((long)timeForRevolution) * 360f;
            RadarView mRadarView = new RadarView(MyActivity.this,radarPointsArray,radarAngle);
            radarLayout.removeAllViewsInLayout();
            radarTimerLayout.addView(mRadarView);
            timeRemaining = millisUntilFinished;
        }
        public void onFinish() {
        }
    }.start();

考虑使用NineOldAndroids的ObjectAnimator而不是Timer可能会更好。虽然ObjectAnimator倾向于永远不会停止和耗尽电池，除非你添加一个功能来阻止它。

为Android应用程序创建动态雷达

1 个答案: