Android CountDownTimer並在畫布上繪制

Question

我正在創建聖誕節倒計時，我需要每秒倒數，並且需要在畫布上繪制聖誕節多少天，幾小時，幾分幾秒。

我可以得到工作結果，但是我覺得有比現在更多的方法來實現這一目標。

這是代碼，我刪除了一些不必要的代碼，例如導入，未實現的方法等。

 public class SnowFall extends Activity {

SampleView textDraw;
Paint paint;
Rect bounds;
int durationMilli;
Duration duration;

static String days;
static String hours;
static String minutes;
static String seconds;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    Duration duration = new Duration();
    int futureTime = duration.cal_duration();
    MyTime tm = new MyTime(futureTime, 1000);
    tm.start();

    textDraw = new SampleView(this);

    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);

    LinearLayout linearLayout = new LinearLayout(this);
    linearLayout.setOrientation(LinearLayout.VERTICAL);
    linearLayout.setBackgroundColor(Color.TRANSPARENT);
    textDraw.setBackgroundDrawable(getResources().getDrawable(
            R.drawable.background_image_1));
    linearLayout.addView(textDraw);
    setContentView(linearLayout);

}

public class MyTime extends CountDownTimer {

    public MyTime(long millisInFuture, long countDownInterval) {
        super(millisInFuture, countDownInterval);

    }

    @Override
    public void onTick(long millisUntilFinished) {

        SampleView view = new SampleView(getApplicationContext());
        int durationInMilliSec = (int) millisUntilFinished;
        Log.d("Joda Time", String.valueOf(durationInMilliSec));

        try {
            int x = durationInMilliSec / 1000;
            seconds = String.valueOf(x % 60);
            x /= 60;
            minutes = String.valueOf(x % 60);
            x /= 60;
            hours = String.valueOf(x % 24);
            x /= 24;
            days = String.valueOf(x);

            view.invalidate();
        } catch (Exception e) {

        }

    }

}

private static class SampleView extends View {
    private Paint mPaint;
    private float mX;
    private float[] mPos;

    private Path mPath;
    private Paint mPathPaint;

    private static final int DY = 45;
    private static final String POSTEXT = "Positioned";

    private static void makePath(Path p) {
        p.moveTo(10, 0);
        p.cubicTo(100, -50, 200, 50, 300, 0);
    }

    private float[] buildTextPositions(String text, float y, Paint paint) {
        float[] widths = new float[text.length()];
        // initially get the widths for each char
        int n = paint.getTextWidths(text, widths);
        // now popuplate the array, interleaving spaces for the Y values
        float[] pos = new float[n * 2];
        float accumulatedX = 0;
        for (int i = 0; i < n; i++) {
            pos[i * 2 + 0] = accumulatedX;
            pos[i * 2 + 1] = y;
            accumulatedX += widths[i];
        }
        return pos;
    }

    public SampleView(Context context) {
        super(context);
        setFocusable(true);

        mPaint = new Paint();
        mPaint.setAntiAlias(true);
        mPaint.setTextSize(40);
        Typeface typeface = Typeface.createFromAsset(context.getAssets(),
                "font.ttf");
        mPaint.setTypeface(typeface);

        mPos = buildTextPositions(POSTEXT, 0, mPaint);

        mPath = new Path();
        makePath(mPath);

        mPathPaint = new Paint();
        mPathPaint.setAntiAlias(true);
        mPathPaint.setColor(0x800000FF);
        mPathPaint.setStyle(Paint.Style.STROKE);
    }

    @Override
    protected void onDraw(Canvas canvas) {

        Paint p = mPaint;
        float x = mX;
        float y = 0;

        if (days != null && hours != null && minutes != null
                && seconds != null) {
            canvas.translate(0, DY);
            p.setTextAlign(Paint.Align.CENTER);
            canvas.drawText("There is", x, y, p);

            canvas.translate(0, DY);
            p.setTextAlign(Paint.Align.CENTER);
            canvas.drawText(days + " Days, " + hours + " Hours", x, y, p);

            canvas.translate(0, DY);
            p.setTextAlign(Paint.Align.CENTER);
            canvas.drawText(minutes + " Minutes and " + seconds
                    + " seconds", x, y, p);

            canvas.translate(0, DY);
            p.setTextAlign(Paint.Align.CENTER);
            canvas.drawText("until christmas.", x, y, p);

            invalidate();

        } else {

            // draw the normal strings
            canvas.translate(0, DY);
            p.setTextAlign(Paint.Align.CENTER);
            canvas.drawText("Something Wrong", x, y, p);

            canvas.translate(0, DY);
            p.setTextAlign(Paint.Align.CENTER);
            canvas.drawText("Check your device time.", x, y, p);

        }
    }

    @Override
    protected void onSizeChanged(int w, int h, int ow, int oh) {
        super.onSizeChanged(w, h, ow, oh);
        mX = w * 0.5f; // remember the center of the screen
    }

}

} 

計算多少天是一個小問題，因為它表明聖誕節只有10天。 我對android上的圖形一無所知，為此做了很多努力。

package in.isuru.animation;

import org.joda.time.DateTime;
import org.joda.time.Seconds;

public class Duration {

public int cal_duration(){
    DateTime start = new DateTime(DateTime.now());
    DateTime end = new DateTime(2012, 12, 25, 0, 0, 0 ,0);
    int differenceSeconds = Seconds.secondsBetween(end, start).getSeconds();

    return differenceSeconds * 1000;
}

}

問題在於它計算出天，小時，分鍾和秒的每個刻度上。 請給我有關這是好的還是有更好的方法的反饋？

Answer 1

只需使用這個簡單的代碼

countDownTimer = new CountDownTimer(240000, 1000) {

    public void onTick(long millisUntilFinished) {
        int seconds = (int) ((millisUntilFinished/1000)%60);
        int minutes = (int) ((millisUntilFinished/1000)/60);
        int hours = (int) ((millisUntilFinished/1000)/3600);
        String startTime ="Time " + String.format("%02d:%02d:%02d",hours,minutes,seconds);
        txtShowTimer.setText(startTime);
    }

    public void onFinish() {
        txtShowTimer.setText("done!");
    }   
}.start();

Answer 2

您的數字將是錯誤的，因為您將int數據類型溢出了毫秒。 一個int的最大值是2 ^ 31〜2 x 10 ^ 9。 距聖誕節還剩155 x 10 ^ 9毫秒。

只需計算秒數，您就可以了。 或者，您可以使用64位long而不是int 。 但是您乘以1000得到毫秒，然后立即除以1000！ 這沒有多大意義。

最好還是在喬達時間里穿行！

既然您已經在使用它，為什么不建一個時期呢？

DateTime start = DateTime.now();  // Note your code makes an unneeded copy here
DateTime end = new DateTime(2012, 12, 25, 0, 0, 0);
Period p = new Period(start, end);

該期間的吸氣劑為年，月，日，小時，分鍾，秒。 這將完全避免容易出錯的計算。