Android性能优化（一）

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <item name="android:windowFullscreen">true</item>
        <item name="android:windowIsTranslucent">true</item>
    </style>

    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <item name="android:windowBackground">@drawable/lunch</item>  //闪屏页图片
        <item name="android:windowFullscreen">true</item>
        <item name="android:windowDrawsSystemBarBackgrounds">false</item><!--显示虚拟按键，并腾出空间-->
    </style>

C:\Android\Demo>adb shell am start -S -W com.example.moneyqian.demo/com.example.moneyqian.demo.MainActivity
Stopping: com.example.moneyqian.demo
Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=com.example.moneyqian.demo/.MainActivity }
Status: ok
Activity: com.example.moneyqian.demo/.MainActivity
ThisTime: 2247
TotalTime: 2247
WaitTime: 2278
Complete

//ActivityRecord

    private void reportLaunchTimeLocked(final long curTime) {
		``````
        final long thisTime = curTime - displayStartTime;
        final long totalTime = stack.mLaunchStartTime != 0 ? (curTime - stack.mLaunchStartTime) : thisTime;
    }

        new Thread(new Runnable() {
            @Override
            public void run() {
                //设置线程的优先级，不与主线程抢资源
                Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND);
				//子线程初始化第三方组件
				Thread.sleep(5000);//建议延迟初始化，可以发现是否影响其它功能，或者是崩溃！
            }
        }).start();

        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
				//延迟初始化组件
            }
        }, 3000);

//Application

    @Override
    protected void attachBaseContext(Context base) {
        super.attachBaseContext(base);
		SPUtil.putLong("application_attach_time", System.currentTimeMillis());//记录Application初始化时间
    }

//入口Activity

    @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        super.onWindowFocusChanged(hasFocus);
  
          long appAttachTime = SPUtil.getLong("application_attach_time");
          long diffTime = System.currentTimeMillis() - appAttachTime;//从application到入口Acitity的时间
 
		 //所以闪屏页展示的时间为 2000ms - diffTime.
    }

//ActivityStack


 final void startActivityLocked(ActivityRecord r, boolean newTask, boolean keepCurTransition,
            ActivityOptions options) {

		``````
        if (!isHomeStack() || numActivities() > 0) {//HOME_STACK表示Launcher桌面所在的Stack
	        // 1.首先当前启动栈不在Launcher的桌面栈里,并且当前系统已经有激活过Activity
	        
            // We want to show the starting preview window if we are
            // switching to a new task, or the next activity's process is
            // not currently running.

            boolean doShow = true;
            if (newTask) {
	            // 2.要将该Activity组件放在一个新的任务栈中启动
	            
                // Even though this activity is starting fresh, we still need
                // to reset it to make sure we apply affinities to move any
                // existing activities from other tasks in to it.
                if ((r.intent.getFlags() & Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED) != 0) {
                    resetTaskIfNeededLocked(r, r);
                    doShow = topRunningNonDelayedActivityLocked(null) == r;
                }
            } else if (options != null && options.getAnimationType()
                    == ActivityOptions.ANIM_SCENE_TRANSITION) {
                doShow = false;
            }
            if (r.mLaunchTaskBehind) {
	            //3. 热启动，不需要启动窗口
	            
                // Don't do a starting window for mLaunchTaskBehind. More importantly make sure we
                // tell WindowManager that r is visible even though it is at the back of the stack.
                mWindowManager.setAppVisibility(r.appToken, true);
                ensureActivitiesVisibleLocked(null, 0, !PRESERVE_WINDOWS);
            } else if (SHOW_APP_STARTING_PREVIEW && doShow) {

				``````
				//4. 显示启动窗口
                r.showStartingWindow(prev, showStartingIcon);
            }
        } else {
	        // 当前启动的是桌面Launcher (开机启动)
            // If this is the first activity, don't do any fancy animations,
            // because there is nothing for it to animate on top of.
			``````
        }

    }

//ActivityRecord


    void showStartingWindow(ActivityRecord prev, boolean createIfNeeded) {
        final CompatibilityInfo compatInfo =
                service.compatibilityInfoForPackageLocked(info.applicationInfo);
        final boolean shown = service.mWindowManager.setAppStartingWindow(
                appToken, packageName, theme, compatInfo, nonLocalizedLabel, labelRes, icon,
                logo, windowFlags, prev != null ? prev.appToken : null, createIfNeeded);
        if (shown) {
            mStartingWindowState = STARTING_WINDOW_SHOWN;
        }
    }

//WindowManagerService

 @Override
    public boolean setAppStartingWindow(IBinder token, String pkg,
            int theme, CompatibilityInfo compatInfo,
            CharSequence nonLocalizedLabel, int labelRes, int icon, int logo,
            int windowFlags, IBinder transferFrom, boolean createIfNeeded) {

        synchronized(mWindowMap) {

			//1. 启动窗口也是需要token的
            AppWindowToken wtoken = findAppWindowToken(token);
            
			//2. 如果已经设置过启动窗口了，不继续处理
            if (wtoken.startingData != null) {
                return false;
            }

            // If this is a translucent window, then don't
            // show a starting window -- the current effect (a full-screen
            // opaque starting window that fades away to the real contents
            // when it is ready) does not work for this.
            if (theme != 0) {
                AttributeCache.Entry ent = AttributeCache.instance().get(pkg, theme,
                        com.android.internal.R.styleable.Window, mCurrentUserId);
                        
               //3. 一堆代码对主题判断，不符合要求则不显示启动窗口（如透明主题）
                if (windowIsTranslucent) {
                    return false;
                }
                if (windowIsFloating || windowDisableStarting) {
                    return false;
                }
				``````
            }

			//4. 创建StartingData，并且通过Handler发送消息

            wtoken.startingData = new StartingData(pkg, theme, compatInfo, nonLocalizedLabel,
                    labelRes, icon, logo, windowFlags);
            Message m = mH.obtainMessage(H.ADD_STARTING, wtoken);
            // Note: we really want to do sendMessageAtFrontOfQueue() because we
            // want to process the message ASAP, before any other queued
            // messages.

            mH.sendMessageAtFrontOfQueue(m);
        }
        return true;
    }

//WindowManagerService --> H 

        public void handleMessage(Message msg) {
            switch (msg.what) {

                case ADD_STARTING: {
                    final AppWindowToken wtoken = (AppWindowToken)msg.obj;
                    final StartingData sd = wtoken.startingData;

                    View view = null;
                    try {
                        final Configuration overrideConfig = wtoken != null && wtoken.mTask != null
                                ? wtoken.mTask.mOverrideConfig : null;
                        view = mPolicy.addStartingWindow(wtoken.token, sd.pkg, sd.theme,
                            sd.compatInfo, sd.nonLocalizedLabel, sd.labelRes, sd.icon, sd.logo,
                            sd.windowFlags, overrideConfig);
                    } catch (Exception e) {
                        Slog.w(TAG_WM, "Exception when adding starting window", e);
                    }

                    ``````
      
                } break;
   }     

//PhoneWindowManager


@Override
    public View addStartingWindow(IBinder appToken, String packageName, int theme,
            CompatibilityInfo compatInfo, CharSequence nonLocalizedLabel, int labelRes,
            int icon, int logo, int windowFlags, Configuration overrideConfig) {
            
         //可以通过SHOW_STARTING_ANIMATIONS设置不显示启动窗口
        if (!SHOW_STARTING_ANIMATIONS) {
            return null;
        }
        WindowManager wm = null;
        View view = null;

        try {
	        //1. 获取上下文Context和主题theme以及标题
            Context context = mContext;
            if (theme != context.getThemeResId() || labelRes != 0) {
                try {
                    context = context.createPackageContext(packageName, 0);
                    context.setTheme(theme);
                } catch (PackageManager.NameNotFoundException e) {
                    // Ignore
                }
            }

			//2. 创建PhoneWindow 用来显示
            final PhoneWindow win = new PhoneWindow(context);
            win.setIsStartingWindow(true);

			//3. 设置当前窗口type和flag,源码注释中描述的很清晰...
            win.setType(
                WindowManager.LayoutParams.TYPE_APPLICATION_STARTING);

            // Force the window flags: this is a fake window, so it is not really
            // touchable or focusable by the user.  We also add in the ALT_FOCUSABLE_IM
            // flag because we do know that the next window will take input
            // focus, so we want to get the IME window up on top of us right away.
            win.setFlags(
                windowFlags|
                WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE|
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE|
                WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM,
                windowFlags|
                WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE|
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE|
                WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM);

            win.setLayout(WindowManager.LayoutParams.MATCH_PARENT,
                    WindowManager.LayoutParams.MATCH_PARENT);

			``````
			
            view = win.getDecorView();

			//4. WindowManager的绘制流程
            wm.addView(view, params);

            return view.getParent() != null ? view : null;
        } catch (WindowManager.BadTokenException e) {
            // ignore
        } catch (RuntimeException e) {
            // don't crash if something else bad happens, for example a
            // failure loading resources because we are loading from an app
            // on external storage that has been unmounted.
            Log.w(TAG, appToken + " failed creating starting window", e);
        }
        return null;
    }

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">

<ListView
android:id="@+id/list_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:divider="#F1F1F1"
android:dividerHeight="1dp"
android:background="@android:color/white"
android:scrollbars="vertical">
</ListView>

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="52dp"
android:background="@drawable/ts_account_list_selector">

<TextView
android:id="@+id/ts_item_has_login_account"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:layout_marginTop="4dp"
android:gravity="center"
android:text="12345678999"
android:textColor="@android:color/black"
android:textSize="16sp" />

<LinearLayout
android:layout_width="wrap_content"
android:layout_height="20dp"
android:layout_alignParentBottom="true"
android:layout_marginBottom="3dp"
android:layout_marginLeft="10dp"
android:gravity="center_vertical" >

<ImageView
android:id="@+id/ts_item_time_clock_image"
android:layout_width="12dp"
android:layout_height="12dp"
android:src="@mipmap/ts_login_clock" />

<TextView
android:id="@+id/ts_item_last_login_time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:layout_toRightOf="@id/ts_item_time_clock_image"
android:text="上次登录"
android:textColor="@android:color/darker_gray"
android:textSize="11sp" />

<TextView
android:id="@+id/ts_item_login_time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:layout_toRightOf="@id/ts_item_last_login_time"
android:text="59分钟前"
android:textColor="@android:color/darker_gray"
android:textSize="11sp" />
</LinearLayout>

<TextView
android:id="@+id/ts_item_always_account_image_tips"
android:layout_width="wrap_content"
android:layout_height="13dp"
android:layout_alignParentRight="true"
android:layout_marginTop="2dp"
android:background="@mipmap/ts_always_account_bg"
android:gravity="center"
android:text="常用"
android:textColor="@android:color/white"
android:textSize="9sp" />

<ImageView
android:id="@+id/ts_item_delete_account_image"
android:layout_width="12dp"
android:layout_height="12dp"
android:layout_alignParentRight="true"
android:layout_marginTop="2dp"
android:layout_marginRight="13dp"
android:layout_centerVertical="true"
android:src="@mipmap/ts_close" />

</RelativeLayout>

public class DroidCard {

public int x;//左侧绘制起点
public int width;
public int height;
public Bitmap bitmap;

public DroidCard(Resources res,int resId,int x){
this.bitmap = BitmapFactory.decodeResource(res,resId);
this.x = x;
this.width = this.bitmap.getWidth();
this.height = this.bitmap.getHeight();
}
}

public class DroidCardsView extends View {
//图片与图片之间的间距
private int mCardSpacing = 150;
//图片与左侧距离的记录
private int mCardLeft = 10;

private List<DroidCard> mDroidCards = new ArrayList<DroidCard>();

private Paint paint = new Paint();

public DroidCardsView(Context context) {
super(context);
initCards();
}

public DroidCardsView(Context context, AttributeSet attrs) {
super(context, attrs);
initCards();
}
/**
* 初始化卡片集合
*/
protected void initCards(){
Resources res = getResources();
mDroidCards.add(new DroidCard(res,R.drawable.alex,mCardLeft));

mCardLeft+=mCardSpacing;
mDroidCards.add(new DroidCard(res,R.drawable.claire,mCardLeft));

mCardLeft+=mCardSpacing;
mDroidCards.add(new DroidCard(res,R.drawable.kathryn,mCardLeft));
}

@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
for (DroidCard c : mDroidCards){
drawDroidCard(canvas, c);
}
invalidate();
}

/**
* 绘制DroidCard
*/
private void drawDroidCard(Canvas canvas, DroidCard c) {
canvas.drawBitmap(c.bitmap,c.x,0f,paint);
}
}

public class DroidCardsView extends View {

//图片与图片之间的间距
private int mCardSpacing = 150;
//图片与左侧距离的记录
private int mCardLeft = 10;

private List<DroidCard> mDroidCards = new ArrayList<DroidCard>();

private Paint paint = new Paint();

public DroidCardsView(Context context) {
super(context);
initCards();
}

public DroidCardsView(Context context, AttributeSet attrs) {
super(context, attrs);
initCards();
}
/**
* 初始化卡片集合
*/
protected void initCards(){
Resources res = getResources();
mDroidCards.add(new DroidCard(res, R.drawable.alex,mCardLeft));

mCardLeft+=mCardSpacing;
mDroidCards.add(new DroidCard(res, R.drawable.claire,mCardLeft));

mCardLeft+=mCardSpacing;
mDroidCards.add(new DroidCard(res, R.drawable.kathryn,mCardLeft));
}

@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
for (int i = 0; i < mDroidCards.size() - 1; i++){
drawDroidCard(canvas, mDroidCards,i);
}
drawLastDroidCard(canvas,mDroidCards.get(mDroidCards.size()-1));
invalidate();
}

/**
* 绘制最后一个DroidCard
* @param canvas
* @param c
*/
private void drawLastDroidCard(Canvas canvas,DroidCard c) {
canvas.drawBitmap(c.bitmap,c.x,0f,paint);
}

/**
* 绘制DroidCard
* @param canvas
* @param mDroidCards
* @param i
*/
private void drawDroidCard(Canvas canvas,List<DroidCard> mDroidCards,int i) {
DroidCard c = mDroidCards.get(i);
canvas.save();
canvas.clipRect((float)c.x,0f,(float)(mDroidCards.get(i+1).x),(float)c.height);
canvas.drawBitmap(c.bitmap,c.x,0f,paint);
canvas.restore();
}
}

FATAL EXCEPTION: main
Process: com.cchip.csmart, PID: 27456
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(int)' on a null object reference
at com.cchip.alicsmart.activity.SplashActivity$1.handleMessage(SplashActivity.java:67)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:179)
at android.app.ActivityThread.main(ActivityThread.java:5672)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:674)

//system logcat:
10-25 17:13:47.788 21430 21430 D dalvikvm: Trying to load lib ...

//event logcat:
10-25 17:13:47.788 21430 21430 I am_on_resume_called: 生命周期
10-25 17:13:47.788 21430 21430 I am_low_memory: 系统内存不足
10-25 17:13:47.788 21430 21430 I am_destroy_activity: 销毁 Activty
10-25 17:13:47.888 21430 21430 I am_anr: ANR 以及原因
10-25 17:13:47.888 21430 21430 I am_kill: APP 被杀以及原因

Name: com.xmamiga.name // 进程名
FDSize: 800 // 当前进程申请的文件句柄个数
VmPeak: 3004628 kB // 当前进程的虚拟内存峰值大小
VmSize: 2997032 kB // 当前进程的虚拟内存大小
Threads: 600 // 当前进程包含的线程个数

opened files count 812:
0 -> /dev/null
1 -> /dev/log/main4
2 -> /dev/binder
3 -> /data/data/com.xmamiga.sample/files/test.conf
...

threads count 412:
1820 com.xmamiga.crashsdk
1844 ReferenceQueueD
1869 FinalizerDaemon
...

private static Handler mShakeHandler = new Handler() {
    @Override public void handleMessage(Message msg) {
        super.handleMessage(msg);
        // 频繁创建对象，模拟内存抖动
        for(int index = 0;index <= 100;index ++) {
            String strArray[] = new String[100000];
        }
        mShakeHandler.sendEmptyMessageDelayed(0,30);
    }
};

/**
 * 模拟内存泄露的Activity
 */
public class MemoryLeakActivity extends AppCompatActivity implements CallBack{
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_memoryleak);
        ImageView imageView = findViewById(R.id.iv_memoryleak);
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.splash);
        imageView.setImageBitmap(bitmap);
        
        // 添加静态类引用
        CallBackManager.addCallBack(this);
    }
    @Override
    protected void onDestroy() {
        super.onDestroy();
//        CallBackManager.removeCallBack(this);
    }
    @Override
    public void dpOperate() {
        // do sth
    }

hprof-conv 刚刚生成的hprof文件 memory-mat.hprof

@Override
protected void onDestroy() {
    super.onDestroy();
    CallBackManager.removeCallBack(this);
}

implementation 'me.weishu:epic:0.3.6'

public class CheckBitmapHook extends XC_MethodHook {
    @Override protected void afterHookedMethod(MethodHookParam param) throws Throwable {
        super.afterHookedMethod(param);
        ImageView imageView = (ImageView)param.thisObject;
        checkBitmap(imageView,imageView.getDrawable());
    }
    private static void checkBitmap(Object o,Drawable drawable) {
        if(drawable instanceof BitmapDrawable && o instanceof View) {
            final Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();
            if(bitmap != null) {
                final View view = (View)o;
                int width = view.getWidth();
                int height = view.getHeight();
                if(width > 0 && height > 0) {
                    if(bitmap.getWidth() > (width <<1) && bitmap.getHeight() > (height << 1)) {
                        warn(bitmap.getWidth(),bitmap.getHeight(),width,height,
                                new RuntimeException("Bitmap size is too large"));
                    }
                } else {
                    final Throwable stacktrace = new RuntimeException();
                    view.getViewTreeObserver().addOnPreDrawListener(
                            new ViewTreeObserver.OnPreDrawListener() {
                                @Override public boolean onPreDraw() {
                                    int w = view.getWidth();
                                    int h = view.getHeight();
                                    if(w > 0 && h > 0) {
                                        if (bitmap.getWidth() >= (w << 1)
                                                && bitmap.getHeight() >= (h << 1)) {
                                            warn(bitmap.getWidth(), bitmap.getHeight(), w, h, stacktrace);
                                        }
                                        view.getViewTreeObserver().removeOnPreDrawListener(this);
                                    }
                                    return true;
                                }
                            });
                }
            }
        }
    }
    private static void warn(int bitmapWidth, int bitmapHeight, int viewWidth, int viewHeight, Throwable t) {
        String warnInfo = new StringBuilder("Bitmap size too large: ")
                .append("\n real size: (").append(bitmapWidth).append(',').append(bitmapHeight).append(')')
                .append("\n desired size: (").append(viewWidth).append(',').append(viewHeight).append(')')
                .append("\n call stack trace: \n").append(Log.getStackTraceString(t)).append('\n')
                .toString();
        LogUtils.i(warnInfo);Application初始化时注入Hook

@Override protected void afterHookedMethod(MethodHookParam param) throws Throwable {

    super.afterHookedMethod(param);

    DexposedBridge.findAndHookMethod(ImageView.class,"setImageBitmap", Bitmap.class,

            new CheckBitmapHook());

}