Android 开发错误集锦
1. eclipse的Device中不显示手机
在eclipse中连接不上手机,出现adb server didn't ACK fail to start daemon 错误.
出现这种原因是因为adb所使用的5037端口被占用了.
使用adb kill-server 关闭adb服务 , 使用adb start-server开启adb命令 ; 如果5037端口被占用则会出现启动失败, 报出上述错误;
查看哪些进程占用了端口 : netstat -ano | findstr "5037" 会出现下面的结果
G:\Documents and Settings\Administrator>netstat -ano | findstr "5037" TCP 127.0.0.1:1939 127.0.0.1:5037 ESTABLISHED 5748 TCP 127.0.0.1:1978 127.0.0.1:5037 ESTABLISHED 3000 TCP 127.0.0.1:5037 0.0.0.0:0 LISTENING 5748 TCP 127.0.0.1:5037 127.0.0.1:1939 ESTABLISHED 5748 TCP 127.0.0.1:5037 127.0.0.1:1977 CLOSE_WAIT 5748 TCP 127.0.0.1:5037 127.0.0.1:1978 ESTABLISHED 5748
可以看到 5748 3000 两个进程占用了5037端口.
打开进程管理器, 点击查看,选择列,将PID进程标示符勾选上,然后根据pid终止相应的进程.
这两个进程分别是豌豆荚 和 QQ , 同时将adb.exe 和 tadb.exe 进程干掉.
此时执行 adb start-server 命令即可启动adb服务 , 之后启动就会启动成功.
2. java.lang.OutOfMemoryError: thread creation failed 错误
10-17 09:51:58.830: E/AndroidRuntime(15695): FATAL EXCEPTION: Thread-316 10-17 09:51:58.830: E/AndroidRuntime(15695): java.lang.OutOfMemoryError: thread creation failed 10-17 09:51:58.830: E/AndroidRuntime(15695): at java.lang.VMThread.create(Native Method) 10-17 09:51:58.830: E/AndroidRuntime(15695): at java.lang.Thread.start(Thread.java:1050) 10-17 09:51:58.830: E/AndroidRuntime(15695): at com.ivt.mHealth.alarm.AlarmPlayer.enqueue(AlarmPlayer.java:201) 10-17 09:51:58.830: E/AndroidRuntime(15695): at com.ivt.mHealth.alarm.AlarmPlayer.resume(AlarmPlayer.java:192) 10-17 09:51:58.830: E/AndroidRuntime(15695): at com.ivt.mHealth.director.MpmDirector.filterMpmHealthData(MpmDirector.java:270) 10-17 09:51:58.830: E/AndroidRuntime(15695): at com.ivt.mHealth.director.MpmDirector.onHealthDataDecoded(MpmDirector.java:72) 10-17 09:51:58.830: E/AndroidRuntime(15695): at com.ivt.mHealth.decoder.BaseDecoder.notifyAllDataDecodedListener(BaseDecoder.java:89) 10-17 09:51:58.830: E/AndroidRuntime(15695): at com.ivt.mHealth.decoder.MpmEcgDecoder.caculateEcgResult(MpmEcgDecoder.java:394) 10-17 09:51:58.830: E/AndroidRuntime(15695): at com.ivt.mHealth.decoder.MpmEcgDecoder.casulateResult(MpmEcgDecoder.java:269) 10-17 09:51:58.830: E/AndroidRuntime(15695): at com.ivt.mHealth.decoder.MpmEcgDecoder.processBigPackageOfEcgData(MpmEcgDecoder.java:100) 10-17 09:51:58.830: E/AndroidRuntime(15695): at com.ivt.mHealth.decoder.MpmEcgDecoder.processData(MpmEcgDecoder.java:87) 10-17 09:51:58.830: E/AndroidRuntime(15695): at com.ivt.mHealth.decoder.MpmDecoder.operator(MpmDecoder.java:135) 10-17 09:51:58.830: E/AndroidRuntime(15695): at com.ivt.mHealth.BqfjApplication$2.receiveData(BqfjApplication.java:148) 10-17 09:51:58.830: E/AndroidRuntime(15695): at com.ivt.mHealth.bluetooth.BqfjBluetoothManager.notifyReceivers(BqfjBluetoothManager.java:281) 10-17 09:51:58.830: E/AndroidRuntime(15695): at com.ivt.mHealth.bluetooth.BqfjConnectionManager$DataPump.run(BqfjConnectionManager.java:397) 10-17 09:51:58.830: E/AndroidRuntime(15695): at com.ivt.mHealth.util.ReusableThread.run(ReusableThread.java:85) 10-17 09:51:58.830: E/AndroidRuntime(15695): at java.lang.Thread.run(Thread.java:856) 10-17 09:51:58.920: V/StagefrightPlayer(1875): isPlaying 10-17 09:51:58.920: V/MediaPlayerService(1875): [20] isPlaying: 0 10-17 09:51:58.920: V/MediaPlayer(15695): isPlaying: 0 10-17 09:51:58.920: V/MediaPlayer-JNI(15695): isPlaying: 0 10-17 09:51:58.925: D/dalvikvm(2219): GC_FOR_ALLOC freed 1595K, 30% free 26891K/37895K, paused 77ms, total 77ms 10-17 09:51:58.930: E/SQLiteLog(15695): (14) cannot open file at line 30241 of [00bb9c9ce4] 10-17 09:51:58.930: E/SQLiteLog(15695): (14) os_unix.c:30241: (2) open(/NotificationPermissions.db) - 10-17 09:51:58.930: D/STATUSBAR-NetworkController(2441): refreshSignalCluster: data=-1 bt=false
开发中遇到了上述错误 , 后来发现是 使用了TraceView导致的
不知道在代码的什么地方添加了TraceView的相关代码 , 去掉之后 , 就好了
我在Activity中的onCreate()方法中添加了 :
Debug.startMethodTracing();
在onDestroy()方法中添加了 :
Debug.stopMethodTracing();
去掉了上述两行代码 , 就不会出现上述错误了 ;
3. Call requires API level 8 (current min is 1)错误
导入了一个程序 , 每次运行之后都会出现该错误 .
点击clean 错误就会消失 , 但是执行该错误的时候该错误就会重新出现 .
这个错误需要在AndroidManifest.xml配置文件中修改 user-sdk 标签
给user-sdk 添加一个android:minSdkVersion="8" 属性
4. 奇怪的空指针异常
今天出现一个奇怪的错误, 很简单空指针异常, 我只负责编码, 不管编译, 然后上传到SVN上, 结果出了下面的错误 , 看了半天 , 木有看懂 :
11-13 10:39:53.337: E/AndroidRuntime(11030): FATAL EXCEPTION: Thread-394 11-13 10:39:53.337: E/AndroidRuntime(11030): java.lang.NullPointerException 11-13 10:39:53.337: E/AndroidRuntime(11030): at com.ivt.mHealth.widget.aa.b(Unknown Source) 11-13 10:39:53.337: E/AndroidRuntime(11030): at com.ivt.mHealth.widget.DisplaySurfaceView.a(Unknown Source) 11-13 10:39:53.337: E/AndroidRuntime(11030): at com.ivt.mHealth.widget.ae.run(Unknown Source)
我一看 蒙了 , 这是什么错误 , 没定义过这个类啊 , 后来才想起来 这是代码混淆以后的效果 .
有点无语 ... 想了半小时才反应过来
我直接从SVN上down了一下代码, 重新编译下 , ╮(╯▽╰)╭ 拨云见日
11-13 10:41:57.432: E/AndroidRuntime(11507): FATAL EXCEPTION: Thread-398 11-13 10:41:57.432: E/AndroidRuntime(11507): java.lang.NullPointerException 11-13 10:41:57.432: E/AndroidRuntime(11507): at com.ivt.mHealth.widget.BpmSurface.drawMpmBpm(BpmSurface.java:169) 11-13 10:41:57.432: E/AndroidRuntime(11507): at com.ivt.mHealth.widget.BpmSurface.drawToSurfaceView(BpmSurface.java:109) 11-13 10:41:57.432: E/AndroidRuntime(11507): at com.ivt.mHealth.widget.DisplaySurfaceView.drawToSurface(DisplaySurfaceView.java:183) 11-13 10:41:57.432: E/AndroidRuntime(11507): at com.ivt.mHealth.widget.DisplaySurfaceView.access$1(DisplaySurfaceView.java:178) 11-13 10:41:57.432: E/AndroidRuntime(11507): at com.ivt.mHealth.widget.DisplaySurfaceView$RenderThread.run(DisplaySurfaceView.java:144)
以后千万不要看编译出来的产品的log , 都是混效过的 ........
这是少上传了一行代码到SVN上啊 ...... 泪奔 .... 半小时就这么浪费了
5. 内存溢出错误
adb shell dumpsys meminfo com.ivt.mHealth
08-12 12:48:52.798: I/dalvikvm-heap(15260): Clamp target GC heap from 64.996MB to 64.000MB 08-12 12:48:52.798: D/dalvikvm(15260): GC_FOR_ALLOC freed 1K, 3% free 63863K/65543K, paused 190ms, total 190ms 08-12 12:48:52.798: I/dalvikvm-heap(15260): Forcing collection of SoftReferences for 21473-byte allocation 08-12 12:48:52.988: I/dalvikvm-heap(15260): Clamp target GC heap from 64.987MB to 64.000MB 08-12 12:48:52.988: D/dalvikvm(15260): GC_BEFORE_OOM freed 9K, 3% free 63853K/65543K, paused 186ms, total 186ms 08-12 12:48:52.988: E/dalvikvm-heap(15260): Out of memory on a 21473-byte allocation. 08-12 12:48:52.988: I/dalvikvm(15260): "main" prio=5 tid=1 RUNNABLE 08-12 12:48:52.988: I/dalvikvm(15260): | group="main" sCount=0 dsCount=0 obj=0x40efd508 self=0x40d62778 08-12 12:48:52.988: I/dalvikvm(15260): | sysTid=15260 nice=0 sched=0/0 cgrp=apps handle=1074577200 08-12 12:48:52.988: I/dalvikvm(15260): | schedstat=( 21710980394 3466435126 36123 ) utm=1846 stm=324 core=1 08-12 12:48:52.988: I/dalvikvm(15260): at com.ivt.mHealth.util.ByteArrayBuffer.expand(ByteArrayBuffer.java:~28) 08-12 12:48:52.988: I/dalvikvm(15260): at com.ivt.mHealth.util.ByteArrayBuffer.append(ByteArrayBuffer.java:62) 08-12 12:48:52.988: I/dalvikvm(15260): at com.ivt.mHealth.util.BqfjHttpHeaderPacker.packHttpHeader(BqfjHttpHeaderPacker.java:185) 08-12 12:48:52.988: I/dalvikvm(15260): at com.ivt.mHealth.datacommunication.impl.BqfjSendRTMpmDataMessageHandler$PacketTransController.sendPacket(BqfjSendRTMpmDataMessageHandler.java:770) 08-12 12:48:52.988: I/dalvikvm(15260): at com.ivt.mHealth.datacommunication.impl.BqfjSendRTMpmDataMessageHandler$PacketTransController.onPacketReceived(BqfjSendRTMpmDataMessageHandler.java:814) 08-12 12:48:52.988: I/dalvikvm(15260): at com.ivt.mHealth.datacommunication.impl.BqfjSendRTMpmDataMessageHandler$1.handleMessage(BqfjSendRTMpmDataMessageHandler.java:526) 08-12 12:48:52.988: I/dalvikvm(15260): at android.os.Handler.dispatchMessage(Handler.java:99) 08-12 12:48:52.988: I/dalvikvm(15260): at android.os.Looper.loop(Looper.java:137) 08-12 12:48:52.988: I/dalvikvm(15260): at android.app.ActivityThread.main(ActivityThread.java:4921) 08-12 12:48:52.988: I/dalvikvm(15260): at java.lang.reflect.Method.invokeNative(Native Method) 08-12 12:48:52.988: I/dalvikvm(15260): at java.lang.reflect.Method.invoke(Method.java:511) 08-12 12:48:52.988: I/dalvikvm(15260): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038) 08-12 12:48:52.988: I/dalvikvm(15260): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805) 08-12 12:48:52.988: I/dalvikvm(15260): at dalvik.system.NativeStart.main(Native Method) 08-12 12:48:52.988: D/AndroidRuntime(15260): Shutting down VM 08-12 12:48:52.988: W/dalvikvm(15260): threadid=1: thread exiting with uncaught exception (group=0x40efc2a0) 08-12 12:48:52.993: V/BluetoothSocket.cpp(15260): readNative 08-12 12:48:52.993: E/AndroidRuntime(15260): FATAL EXCEPTION: main 08-12 12:48:52.993: E/AndroidRuntime(15260): java.lang.OutOfMemoryError 08-12 12:48:52.993: E/AndroidRuntime(15260): at com.ivt.mHealth.util.ByteArrayBuffer.expand(ByteArrayBuffer.java:28) 08-12 12:48:52.993: E/AndroidRuntime(15260): at com.ivt.mHealth.util.ByteArrayBuffer.append(ByteArrayBuffer.java:62) 08-12 12:48:52.993: E/AndroidRuntime(15260): at com.ivt.mHealth.util.BqfjHttpHeaderPacker.packHttpHeader(BqfjHttpHeaderPacker.java:185) 08-12 12:48:52.993: E/AndroidRuntime(15260): at com.ivt.mHealth.datacommunication.impl.BqfjSendRTMpmDataMessageHandler$PacketTransController.sendPacket(BqfjSendRTMpmDataMessageHandler.java:770) 08-12 12:48:52.993: E/AndroidRuntime(15260): at com.ivt.mHealth.datacommunication.impl.BqfjSendRTMpmDataMessageHandler$PacketTransController.onPacketReceived(BqfjSendRTMpmDataMessageHandler.java:814) 08-12 12:48:52.993: E/AndroidRuntime(15260): at com.ivt.mHealth.datacommunication.impl.BqfjSendRTMpmDataMessageHandler$1.handleMessage(BqfjSendRTMpmDataMessageHandler.java:526) 08-12 12:48:52.993: E/AndroidRuntime(15260): at android.os.Handler.dispatchMessage(Handler.java:99) 08-12 12:48:52.993: E/AndroidRuntime(15260): at android.os.Looper.loop(Looper.java:137) 08-12 12:48:52.993: E/AndroidRuntime(15260): at android.app.ActivityThread.main(ActivityThread.java:4921) 08-12 12:48:52.993: E/AndroidRuntime(15260): at java.lang.reflect.Method.invokeNative(Native Method) 08-12 12:48:52.993: E/AndroidRuntime(15260): at java.lang.reflect.Method.invoke(Method.java:511) 08-12 12:48:52.993: E/AndroidRuntime(15260): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038) 08-12 12:48:52.993: E/AndroidRuntime(15260): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805) 08-12 12:48:52.993: E/AndroidRuntime(15260): at dalvik.system.NativeStart.main(Native Method) 08-12 12:48:53.013: E/android.os.Debug(2224): !@Dumpstate > dumpstate -k -t -z -d -o /data/log/dumpstate_app_error 08-12 12:48:53.018: I/dumpstate(308): begin
1.什么是 OutOfMemoryError：
官方引用： Thrown when a request for memory is made that can not be satisfied using the
available platform resources. Such a request may be made by both the running application or by an internal function of the VM.
通俗的讲：就是在请求一块内存的时候，当前可用资源不够用来请求时抛出的一种错误。我们知道，每个 android 程序就是一个独立 dalvik vm 实例，每个实例限制了最大内存占用，如果超过了这个限制，系统就会抛出这个错误。所以跟整个设备的剩余内存没太大关系，当然如果设备剩余内存都不足以再运行一个程序时，系统就会选择 kill 部分程序以确保有足够内存运行其他程序。
2.android 内存组成：
android 内存由 dalvik 和 native 2部分组成，dalvik 也就是 java 堆，创建的对象就是在这里分配的，而 native 是通过 c/c++ 方式申请的内存，Bitmap 就是以一种方式分配的（android3.0 以后，系统默认是通过 dalvik 分配的）。当然无论以何种方式分配，2部分加起来不能超过 android 对单个程序的内存限制。
3.内存限制大小：
1 ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE); 2 activityManager.getMemoryClass();
以上方法会返回以 M 为单位的数字，可能在不同的平台或者设备上值都不太一样，比如：HTC G7 默认 24M，Galaxy 36M，emulator-2.3 24M，等等。
4.程序实际占用：
以一个简单的 android 程序为例，该程序是用 eclipse adt 自动生成的最简单的一个 android 项目，只有1个 activity 和 adt 自动生成的 res 目录，测试环境：emulator-2.3.3
启动该程序，命令行运行：
adb shell dumpsys meminfo com.mem.demo
执行结果：
Applications Memory Usage (kB): Uptime: 1195344 Realtime: 1195344 ** MEMINFO in pid 333 [com.mem.demo] ** native dalvik other total -------------------------------------------------------- | size: 3968 5379 N/A 9347 | | | | allocated: 3964 2649 N/A 6613 | -------------------------------------------------------- free: 3 2730 N/A 2733 (Pss): 553 449 2516 3518 (shared dirty): 2272 1868 6648 10788 (priv dirty): 420 32 1140 1592 Objects Views: 0 ViewRoots: 0 AppContexts: 0 Activities: 0 Assets: 2 AssetManagers: 2 Local Binders: 5 Proxy Binders: 10 Death Recipients: 0 OpenSSL Sockets: 0 SQL heap: 0 MEMORY_USED: 0 PAGECACHE_OVERFLOW: 0 MALLOC_SIZE: 0 Asset Allocations zip:/data/app/com.mem.demo-1.apk:/resources.arsc: 1K
从上面被框出来的部分可以看出，一个最简单的 android 程序在启动后都有 6m 左右内存的占用（上面是 6613kb）。那这 6m 的内存除了该 android 自己的资源和类之外，其他的还有什么呢：
简单说：在初始化的时候会 preload 一些东西，这些就包括 classes 和系统资源，就是系统的一些布局啊，图片啊，等等，在 android 完成启动以后，这部分就通过内存共享的方式共享给其他程序，可以让其他程序可以调用这部分资源，代码可以参考：http://goo.gl/EKvCV，android 整个启动流程可以参考：http://goo.gl/K36Lr 。
5.发生 OOM ：
为了制造 OOM，我们对上面最简单的程序进行了改写：
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package com.mem.demo;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.os.Bundle;public class DemoActivityextends Activity
{ Bitmap
map1, map2, map3, map4; /**
Called when the activity is first created. */ @Override public void onCreate(Bundle
savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); map1
= BitmapFactory.decodeResource(getResources(), R.drawable.big1); map2
= BitmapFactory.decodeResource(getResources(), R.drawable.big2); map3
= BitmapFactory.decodeResource(getResources(), R.drawable.big3); map4
= BitmapFactory.decodeResource(getResources(), R.drawable.big4); }} |
其中：big1 到 big4 都是 1600*900 分辨率的图片，放在 drawbable-hdpi 文件夹下面，启动程序，发生了 OOM：
05-08 07:44:44.372: E/dalvikvm-heap(386): 5760000-byte external allocation too large for this process. 05-08 07:44:44.412: I/dalvikvm-heap(386): Clamp target GC heap from 25.099MB to 24.000MB 05-08 07:44:44.412: E/GraphicsJNI(386): VM won't let us allocate 5760000 bytes 05-08 07:44:44.412: D/dalvikvm(386): GC_FOR_MALLOC freed 0K, 53% free 2548K/5379K, external 18500K/20548K, paused 36ms 05-08 07:44:44.422: D/skia(386): --- decoder->decode returned false 05-08 07:44:44.422: D/AndroidRuntime(386): Shutting down VM 05-08 07:44:44.432: W/dalvikvm(386): threadid=1: thread exiting with uncaught exception (group=0x40015560) 05-08 07:44:44.442: E/AndroidRuntime(386): FATAL EXCEPTION: main 05-08 07:44:44.442: E/AndroidRuntime(386): java.lang.OutOfMemoryError: bitmap size exceeds VM budget 05-08 07:44:44.442: E/AndroidRuntime(386): at android.graphics.BitmapFactory.nativeDecodeAsset(Native Method) 05-08 07:44:44.442: E/AndroidRuntime(386): at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:460) 05-08 07:44:44.442: E/AndroidRuntime(386): at android.graphics.BitmapFactory.decodeResourceStream(BitmapFactory.java:336) 05-08 07:44:44.442: E/AndroidRuntime(386): at android.graphics.BitmapFactory.decodeResource(BitmapFactory.java:359) 05-08 07:44:44.442: E/AndroidRuntime(386): at android.graphics.BitmapFactory.decodeResource(BitmapFactory.java:385) 05-08 07:44:44.442: E/AndroidRuntime(386): at com.mem.demo.DemoActivity.onCreate(DemoActivity.java:20) 05-08 07:44:44.442: E/AndroidRuntime(386): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 05-08 07:44:44.442: E/AndroidRuntime(386): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611) 05-08 07:44:44.442: E/AndroidRuntime(386): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663) 05-08 07:44:44.442: E/AndroidRuntime(386): at android.app.ActivityThread.access$1500(ActivityThread.java:117) 05-08 07:44:44.442: E/AndroidRuntime(386): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931) 05-08 07:44:44.442: E/AndroidRuntime(386): at android.os.Handler.dispatchMessage(Handler.java:99) 05-08 07:44:44.442: E/AndroidRuntime(386): at android.os.Looper.loop(Looper.java:123) 05-08 07:44:44.442: E/AndroidRuntime(386): at android.app.ActivityThread.main(ActivityThread.java:3683) 05-08 07:44:44.442: E/AndroidRuntime(386): at java.lang.reflect.Method.invokeNative(Native Method) 05-08 07:44:44.442: E/AndroidRuntime(386): at java.lang.reflect.Method.invoke(Method.java:507) 05-08 07:44:44.442: E/AndroidRuntime(386): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 05-08 07:44:44.442: E/AndroidRuntime(386): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 05-08 07:44:44.442: E/AndroidRuntime(386): at dalvik.system.NativeStart.main(Native Method)
从日志上看，内存不足发生在 decode big4 这个图片的时候，我们对内存情况进行打印：
Applications Memory Usage (kB): Uptime: 958383 Realtime: 958383 ** MEMINFO in pid 386 [com.mem.demo] ** native dalvik other total size: 25144 5379 N/A 30523 allocated: 20799 2614 N/A 23413 free: 60 2765 N/A 2825 (Pss): 494 426 18494 19414 (shared dirty): 2288 1876 5292 9456 (priv dirty): 360 28 17836 18224
从内存打印情况看出，当前已经分配了 23m 左右内存，同时结合 logcat 错误日志，big4 这个图片需要申请 5760000byte，即:5.76m 的内存，加起来就是 29m 左右内存，我们测试环境是 emulator2.3.3 默认是
24m，内存不足以申请这么多，所以抛出了OOM。
那为什么区区3，4张图片就会让 android 程序内存不足？
设备限制是一方面，像上面第3点说的，每个 android 设备的内存限制不一样，这个程序在模拟器上会有问题，在其他设备上，比如：galaxy 就不会有问题。最主要的还是跟图片所占内存有关系，那么一张图片到底
占用多少内存呢，java 没有 c 的 sizeof() 函数，无法准确去量化这个数值，但是可以有粗略的计算方法：
宽 * 高 * 每个像素所占的 bytes
宽度和高度这个很容易获得，那每个像素所占的 bytes 呢，这个主要取决于 decode 图片的方式：
Bitmap.Config ALPHA_8 Each pixel is stored as a single translucency (alpha) channel.
Bitmap.Config ARGB_4444 This field is deprecated. Because of the poor quality of this configuration, it is advised to use ARGB_8888 instead.
Bitmap.Config ARGB_8888 Each pixel is stored on 4 bytes.
Bitmap.Config RGB_565 Each pixel is stored on 2 bytes and only the RGB channels are encoded: red is stored with 5 bits of precision (32 possible values), green is store d with 6 bits of precision (64 possible values) and blue is stored with 5 bits of precision.
以上是官方文档对 Bitmap.Config 类的描述，所以，如果以
ARGB_8888 的方式 decode，那个每个像素占用4个 bytes，而如果用 RGB_565 就占用2个 bytes。
我们计算一下，在 2.3 以后，程序自带的图片资源，都默认以 ARGB_8888 的方式，而在此以之前是以 RGB_565 的方式（不确定，待验证），所以颜色会有损耗，典型的就是如果有渐变色的话，会出现光圈。
所以，计算如下：
1600 * 900 * 4 = 5760000
这个 5760000 也就是上面 logcat 错误日志里面所提到的申请数字，当然在实际用命令打印出的内存情况上看，比这个数字要大，是因为这只是图片像素的内存，还有一些属性，变量和类本身没有计算在内。
