<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<com.shen.apitest.MyAnalogClock
android:id="@+id/clock"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</RelativeLayout>
文章 要点： 取消了广播接收器，增加了handle message的消息处理机制，
用到的资源图片，都是apiDemo下面的drawable
路径（D:\android-sdk-windows\platforms\android-8\data\res\drawable-hdpi)
package com.shen.apitest;
/*
* Copyright (C) 2006 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.
*/
import java.util.TimeZone;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.os.Handler;
import android.os.Message;
import android.text.format.Time;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.widget.RemoteViews.RemoteView;
import com.shen.R;
/**
* This widget display an analogic clock with two hands for hours and minutes.
*/
@RemoteView
public class MyAnalogClock extends View {
private Time mCalendar;
private Drawable mHourHand;
private Drawable mMinuteHand;
private Drawable mDial;
private int mDialWidth;
private int mDialHeight;
private boolean mAttached;
private float mMinutes;
private float mHour;
private boolean mChanged;
// /增加了秒针显示所用到的秒表
private static String debug = "MyAnalogClock";
private static int SECONDS_FLAG = 0;
private Message secondsMsg;
private float mSeconds;
// /////end
private final Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case 0:
onTimeChanged();// 重新获取的系统的当前时间，得到时，分，秒
invalidate();// 强制绘制，调用自身的onDraw();
break;
default:
break;
}
super.handleMessage(msg);
}
};
public MyAnalogClock(Context context) {
this(context, null);
}
public MyAnalogClock(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public MyAnalogClock(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
Resources r = context.getResources();
if (mDial == null) {
mDial = r.getDrawable(R.drawable.clock_dial);
}
if (mHourHand == null) {
mHourHand = r.getDrawable(R.drawable.clock_hand_hour);
}
if (mMinuteHand == null) {
mMinuteHand = r.getDrawable(R.drawable.clock_hand_minute);
}
mCalendar = new Time();
mDialWidth = mDial.getIntrinsicWidth();
mDialHeight = mDial.getIntrinsicHeight();
}
@Override
/*
* * 吸附到窗体上
*/
protected void onAttachedToWindow() {
Log.e(debug, "onAttachedToWindow");
super.onAttachedToWindow();
if (!mAttached) {
mAttached = true;
// /////////修改到秒针显示后，不需要广播接收器
// IntentFilter filter = new IntentFilter();
//
// filter.addAction(Intent.ACTION_TIME_TICK);// 每隔一分钟会发出这样的一个action
// filter.addAction(Intent.ACTION_TIME_CHANGED);//
// 外部修改系统时间，发出这样的action
// filter.addAction(Intent.ACTION_TIMEZONE_CHANGED);//
// 外部修改系统的时区，发出action
// getContext().registerReceiver(mIntentReceiver, filter);
// null,handler 这两个参数暂时无效，故去掉，
// ///////end
}
// NOTE: It's safe to do these after registering the receiver since the
// receiver always runs
// in the main thread, therefore the receiver can't run before this
// method returns.
// The time zone may have changed while the receiver wasn't registered,
// so update the Time
mCalendar = new Time();
// Make sure we update to the current time
onTimeChanged();
initSecondsThread();
}
private void initSecondsThread() {
secondsMsg = mHandler.obtainMessage(SECONDS_FLAG);
Thread newThread = new Thread() {
@Override
public void run() {
while (mAttached) {
// 如果这个消息不重新获取的话，
// 会抛一个this message is already in use 的异常
secondsMsg = mHandler.obtainMessage(SECONDS_FLAG);
// /end
mHandler.sendMessage(secondsMsg);
try {
sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
};
newThread.start();
}
@Override
/*
* * 脱离窗体 在按home按键，不触发这个事件，所以这个应用的监听还是持续监听着。
* 如果外部修改系统事件，action=Intent.ACTION_TIME_CHANGED 按back按键，触发事件，下次从onCreate从新载入
*/
protected void onDetachedFromWindow() {
Log.e(debug, "onDetachedFromWindow");
super.onDetachedFromWindow();
if (mAttached) {
// getContext().unregisterReceiver(mIntentReceiver); 增加秒针，不需要接收器了。
mAttached = false;
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
Log.e(debug, "onMeasure");
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
float hScale = 1.0f;
float vScale = 1.0f;
if (widthMode != MeasureSpec.UNSPECIFIED && widthSize < mDialWidth) {
hScale = (float) widthSize / (float) mDialWidth;
}
if (heightMode != MeasureSpec.UNSPECIFIED && heightSize < mDialHeight) {
vScale = (float) heightSize / (float) mDialHeight;
}
float scale = Math.min(hScale, vScale);
setMeasuredDimension(resolveSize((int) (mDialWidth * scale),
widthMeasureSpec), resolveSize((int) (mDialHeight * scale),
heightMeasureSpec));
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
Log.e(debug, "onSizeChanged");
super.onSizeChanged(w, h, oldw, oldh);
mChanged = true;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Log.e(debug, "canvas");
boolean changed = mChanged;
if (changed) {
mChanged = false;
}
int availableWidth = getWidth();
int availableHeight = getHeight();
int x = availableWidth / 2;
int y = availableHeight / 2;
final Drawable dial = mDial;
int w = dial.getIntrinsicWidth();
int h = dial.getIntrinsicHeight();
boolean scaled = false;
if (availableWidth < w || availableHeight < h) {
scaled = true;
float scale = Math.min((float) availableWidth / (float) w,
(float) availableHeight / (float) h);
canvas.save();
canvas.scale(scale, scale, x, y);
}
if (changed) {
dial.setBounds(x - (w / 2), y - (h / 2), x + (w / 2), y + (h / 2));
}
dial.draw(canvas);
// //////以上是绘制12个小时背景图
canvas.save();
canvas.rotate(mHour / 12.0f * 360.0f, x, y);
final Drawable hourHand = mHourHand;
if (changed) {
w = hourHand.getIntrinsicWidth();
h = hourHand.getIntrinsicHeight();
hourHand.setBounds(x - (w / 2), y - (h / 2), x + (w / 2), y
+ (h / 2));
}
hourHand.draw(canvas);
canvas.restore();
// //////以上是绘制时针
canvas.save();
canvas.rotate(mMinutes / 60.0f * 360.0f, x, y);
final Drawable minuteHand = mMinuteHand;
if (changed) {
w = minuteHand.getIntrinsicWidth();
h = minuteHand.getIntrinsicHeight();
minuteHand.setBounds(x - (w / 2), y - (h / 2), x + (w / 2), y
+ (h / 2));
}
minuteHand.draw(canvas);
canvas.restore();
// //////以上是绘制分针
// /增加秒针的绘制
canvas.save();
canvas.rotate(mSeconds / 60.0f * 360.0f, x, y);
final Drawable secondHand = mMinuteHand;// //用时针来代替秒针
if (changed) {
w = secondHand.getIntrinsicWidth();
h = secondHand.getIntrinsicHeight();
secondHand.setBounds(x - (w / 2), y - (h / 2), x + (w / 2), y
+ (h / 2));
}
secondHand.draw(canvas);
canvas.restore();
// /////end
if (scaled) {
canvas.restore();
}
}
/**
* 改变时间
*/
private void onTimeChanged() {
Log.e(debug, "onTimeChanged");
mCalendar.setToNow();// ///获取手机自身的当前时间，而非实际中的标准的北京时间
int hour = mCalendar.hour;// 小时
int minute = mCalendar.minute;// 分钟
int second = mCalendar.second;// 秒
mSeconds = second;
mMinutes = minute + second / 60.0f;
mHour = hour + mMinutes / 60.0f;
mChanged = true;
}
/**
* 这个接收器，只接受三个action， 1.Intent.ACTION_TIME_TICK，每分钟发出一次
* 2.Intent.ACTION_TIME_CHANGE， 外部修改系统时间 3.Intent.ACTION_TIMEZONE_CHANGED
* 外部系统的时区 按home，还能继续监听 按back，监听销毁
*/
private final BroadcastReceiver mIntentReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
Log.e(debug, "onReceive");
Log.e(debug, "intent action=" + intent.getAction());
if (intent.getAction().equals(Intent.ACTION_TIMEZONE_CHANGED)) {
String tz = intent.getStringExtra("time-zone");
mCalendar = new Time(TimeZone.getTimeZone(tz).getID());
}
onTimeChanged();
invalidate();
}
};
}
analogclock.xml