我正在尝试在 Wear 模拟器上使用新的表盘 API，当我扩展 CanvasWatchFaceService 时 onTimeTick 方法从未被触发，因此时钟从未被更新。

我正在使用模拟示例并尝试移除秒针(现在只是禁用计时器):

/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.wearable.watchface;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.wearable.watchface.CanvasWatchFaceService;
import android.support.wearable.watchface.WatchFaceService;
import android.support.wearable.watchface.WatchFaceStyle;
import android.text.format.Time;
import android.util.Log;
import android.view.SurfaceHolder;

import java.util.TimeZone;
import java.util.concurrent.TimeUnit;

/**
 * Sample analog watch face with a ticking second hand. In ambient mode, the second hand isn't
 * shown. On devices with low-bit ambient mode, the hands are drawn without anti-aliasing in ambient
 * mode. The watch face is drawn with less contrast in mute mode.
 *
 * {@link SweepWatchFaceService} is similar but has a sweep second hand.
 */
public class AnalogWatchFaceService extends CanvasWatchFaceService {
    private static final String TAG = "AnalogWatchFaceService";

    /**
     * Update rate in milliseconds for interactive mode. We update once a second to advance the
     * second hand.
     */
    private static final long INTERACTIVE_UPDATE_RATE_MS = TimeUnit.SECONDS.toMillis(1);

    @Override
    public Engine onCreateEngine() {
        return new Engine();
    }

    private class Engine extends CanvasWatchFaceService.Engine {
        static final int MSG_UPDATE_TIME = 0;

        Paint mHourPaint;
        Paint mMinutePaint;
        Paint mSecondPaint;
        Paint mTickPaint;
        boolean mMute;
        Time mTime;

        /** Handler to update the time once a second in interactive mode. */
        final Handler mUpdateTimeHandler = new Handler() {
            @Override
            public void handleMessage(Message message) {
                switch (message.what) {
                    case MSG_UPDATE_TIME:
                        if (Log.isLoggable(TAG, Log.VERBOSE)) {
                            Log.v(TAG, "updating time");
                        }
                        invalidate();
                        if (shouldTimerBeRunning()) {
                            long timeMs = System.currentTimeMillis();
                            long delayMs = INTERACTIVE_UPDATE_RATE_MS
                                    - (timeMs % INTERACTIVE_UPDATE_RATE_MS);
                            mUpdateTimeHandler.sendEmptyMessageDelayed(MSG_UPDATE_TIME, delayMs);
                        }
                        break;
                }
            }
        };

        final BroadcastReceiver mTimeZoneReceiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                mTime.clear(intent.getStringExtra("time-zone"));
                mTime.setToNow();
            }
        };
        boolean mRegisteredTimeZoneReceiver = false;

        /**
         * Whether the display supports fewer bits for each color in ambient mode. When true, we
         * disable anti-aliasing in ambient mode.
         */
        boolean mLowBitAmbient;

        Bitmap mBackgroundBitmap;
        Bitmap mBackgroundScaledBitmap;

        @Override
        public void onCreate(SurfaceHolder holder) {
            if (Log.isLoggable(TAG, Log.DEBUG)) {
                Log.d(TAG, "onCreate");
            }
            super.onCreate(holder);

            setWatchFaceStyle(new WatchFaceStyle.Builder(AnalogWatchFaceService.this)
                    .setCardPeekMode(WatchFaceStyle.PEEK_MODE_SHORT)
                    .setBackgroundVisibility(WatchFaceStyle.BACKGROUND_VISIBILITY_INTERRUPTIVE)
                    .setShowSystemUiTime(false)
                    .build());

            Resources resources = AnalogWatchFaceService.this.getResources();
            Drawable backgroundDrawable = resources.getDrawable(R.drawable.bg);
            mBackgroundBitmap = ((BitmapDrawable) backgroundDrawable).getBitmap();

            mHourPaint = new Paint();
            mHourPaint.setARGB(255, 200, 200, 200);
            mHourPaint.setStrokeWidth(5.f);
            mHourPaint.setAntiAlias(true);
            mHourPaint.setStrokeCap(Paint.Cap.ROUND);

            mMinutePaint = new Paint();
            mMinutePaint.setARGB(255, 200, 200, 200);
            mMinutePaint.setStrokeWidth(3.f);
            mMinutePaint.setAntiAlias(true);
            mMinutePaint.setStrokeCap(Paint.Cap.ROUND);

            mSecondPaint = new Paint();
            mSecondPaint.setARGB(255, 255, 0, 0);
            mSecondPaint.setStrokeWidth(2.f);
            mSecondPaint.setAntiAlias(true);
            mSecondPaint.setStrokeCap(Paint.Cap.ROUND);

            mTickPaint = new Paint();
            mTickPaint.setARGB(100, 255, 255, 255);
            mTickPaint.setStrokeWidth(2.f);
            mTickPaint.setAntiAlias(true);

            mTime = new Time();
        }

        @Override
        public void onDestroy() {
            mUpdateTimeHandler.removeMessages(MSG_UPDATE_TIME);
            super.onDestroy();
        }

        @Override
        public void onPropertiesChanged(Bundle properties) {
            super.onPropertiesChanged(properties);
            mLowBitAmbient = properties.getBoolean(PROPERTY_LOW_BIT_AMBIENT, false);
            if (Log.isLoggable(TAG, Log.DEBUG)) {
                Log.d(TAG, "onPropertiesChanged: low-bit ambient = " + mLowBitAmbient);
            }
        }

        @Override
        public void onTimeTick() {
            super.onTimeTick();
            if (Log.isLoggable(TAG, Log.DEBUG)) {
                Log.d(TAG, "onTimeTick: ambient = " + isInAmbientMode());
            }
            invalidate();
        }

        @Override
        public void onAmbientModeChanged(boolean inAmbientMode) {
            super.onAmbientModeChanged(inAmbientMode);
            if (Log.isLoggable(TAG, Log.DEBUG)) {
                Log.d(TAG, "onAmbientModeChanged: " + inAmbientMode);
            }
            if (mLowBitAmbient) {
                boolean antiAlias = !inAmbientMode;
                mHourPaint.setAntiAlias(antiAlias);
                mMinutePaint.setAntiAlias(antiAlias);
                mSecondPaint.setAntiAlias(antiAlias);
                mTickPaint.setAntiAlias(antiAlias);
            }
            invalidate();

            // Whether the timer should be running depends on whether we're in ambient mode (as well
            // as whether we're visible), so we may need to start or stop the timer.
            updateTimer();
        }

        @Override
        public void onInterruptionFilterChanged(int interruptionFilter) {
            super.onInterruptionFilterChanged(interruptionFilter);
            boolean inMuteMode = (interruptionFilter == WatchFaceService.INTERRUPTION_FILTER_NONE);
            if (mMute != inMuteMode) {
                mMute = inMuteMode;
                mHourPaint.setAlpha(inMuteMode ? 100 : 255);
                mMinutePaint.setAlpha(inMuteMode ? 100 : 255);
                mSecondPaint.setAlpha(inMuteMode ? 80 : 255);
                invalidate();
            }
        }

        @Override
        public void onDraw(Canvas canvas, Rect bounds) {
            mTime.setToNow();



            int width = bounds.width();
            int height = bounds.height();

            // Draw the background, scaled to fit.
            if (mBackgroundScaledBitmap == null
                    || mBackgroundScaledBitmap.getWidth() != width
                    || mBackgroundScaledBitmap.getHeight() != height) {
                mBackgroundScaledBitmap = Bitmap.createScaledBitmap(mBackgroundBitmap,
                        width, height, true /* filter */);
            }
            canvas.drawBitmap(mBackgroundScaledBitmap, 0, 0, null);

            // Find the center. Ignore the window insets so that, on round watches with a
            // "chin", the watch face is centered on the entire screen, not just the usable
            // portion.
            float centerX = width / 2f;
            float centerY = height / 2f;

            // Draw the ticks.
            float innerTickRadius = centerX - 10;
            float outerTickRadius = centerX;
            for (int tickIndex = 0; tickIndex < 12; tickIndex++) {
                float tickRot = (float) (tickIndex * Math.PI * 2 / 12);
                float innerX = (float) Math.sin(tickRot) * innerTickRadius;
                float innerY = (float) -Math.cos(tickRot) * innerTickRadius;
                float outerX = (float) Math.sin(tickRot) * outerTickRadius;
                float outerY = (float) -Math.cos(tickRot) * outerTickRadius;
                canvas.drawLine(centerX + innerX, centerY + innerY,
                        centerX + outerX, centerY + outerY, mTickPaint);
            }

            float secRot = mTime.second / 30f * (float) Math.PI;
            int minutes = mTime.minute;
            float minRot = minutes / 30f * (float) Math.PI;
            float hrRot = ((mTime.hour + (minutes / 60f)) / 6f ) * (float) Math.PI;

            float secLength = centerX - 20;
            float minLength = centerX - 40;
            float hrLength = centerX - 80;

            if (!isInAmbientMode()) {
                float secX = (float) Math.sin(secRot) * secLength;
                float secY = (float) -Math.cos(secRot) * secLength;
                canvas.drawLine(centerX, centerY, centerX + secX, centerY + secY, mSecondPaint);
            }

            float minX = (float) Math.sin(minRot) * minLength;
            float minY = (float) -Math.cos(minRot) * minLength;
            canvas.drawLine(centerX, centerY, centerX + minX, centerY + minY, mMinutePaint);

            float hrX = (float) Math.sin(hrRot) * hrLength;
            float hrY = (float) -Math.cos(hrRot) * hrLength;
            canvas.drawLine(centerX, centerY, centerX + hrX, centerY + hrY, mHourPaint);
        }

        @Override
        public void onVisibilityChanged(boolean visible) {
            super.onVisibilityChanged(visible);
            if (Log.isLoggable(TAG, Log.DEBUG)) {
                Log.d(TAG, "onVisibilityChanged: " + visible);
            }

            if (visible) {
                registerReceiver();

                // Update time zone in case it changed while we weren't visible.
                mTime.clear(TimeZone.getDefault().getID());
                mTime.setToNow();
            } else {
                unregisterReceiver();
            }

            // Whether the timer should be running depends on whether we're visible (as well as
            // whether we're in ambient mode), so we may need to start or stop the timer.
            updateTimer();
        }

        private void registerReceiver() {
            if (mRegisteredTimeZoneReceiver) {
                return;
            }
            mRegisteredTimeZoneReceiver = true;
            IntentFilter filter = new IntentFilter(Intent.ACTION_TIMEZONE_CHANGED);
            AnalogWatchFaceService.this.registerReceiver(mTimeZoneReceiver, filter);
        }

        private void unregisterReceiver() {
            if (!mRegisteredTimeZoneReceiver) {
                return;
            }
            mRegisteredTimeZoneReceiver = false;
            AnalogWatchFaceService.this.unregisterReceiver(mTimeZoneReceiver);
        }

        /**
         * Starts the {@link #mUpdateTimeHandler} timer if it should be running and isn't currently
         * or stops it if it shouldn't be running but currently is.
         */
        private void updateTimer() {
            if (Log.isLoggable(TAG, Log.DEBUG)) {
                Log.d(TAG, "updateTimer");
            }
            mUpdateTimeHandler.removeMessages(MSG_UPDATE_TIME);
            if (shouldTimerBeRunning()) {
                mUpdateTimeHandler.sendEmptyMessage(MSG_UPDATE_TIME);
            }
        }

        /**
         * Returns whether the {@link #mUpdateTimeHandler} timer should be running. The timer should
         * only run when we're visible and in interactive mode.
         */
        private boolean shouldTimerBeRunning() {
            return isVisible() && !isInAmbientMode() && false;
        }

    }
}

最佳答案

onTimeTick 将以环境模式传送给您。查看WatchFaceService的引用:

     Called periodically in ambient mode to update the time shown by the watch face. This
     method is called at least once per minute.

在交互模式下，您需要实现自己的机制。

关于Android Wear WatchFace API onTimeTick 未触发，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/27440982/