复制代码for e in elements:
    e.mutate()

复制代码import audio

core = audio.Core()
controller = audio.Controller()

复制代码import audio

core = audio.AudioCore()
controller = audio.AudioController()

复制代码elements = ...
elements_active = ...
elements_defunct = ...

复制代码elements = ...
active_elements = ...
defunct_elements ...

复制代码person.age = 42

复制代码person.set_age(42)

复制代码import canteen
import canteen.sessions
from canteen import sessions

复制代码from canteen import get_user  # Symbol from canteen/__init__.py
from canteen.sessions import get_session  # Symbol from canteen/sessions.py

复制代码"""Return the pathname of ``foo``."""

复制代码"""Train a model to classify Foos and Bars.

Usage::

    >>> import klassify
    >>> data = [("green", "foo"), ("orange", "bar")]
    >>> classifier = klassify.train(data)

:param train_data: A list of tuples of the form ``(color, label)``.
:rtype: A :class:`Classifier <Classifier>`
"""

复制代码class Person(object):
    """A simple representation of a human being.

    :param name: A string, the person's name.
    :param age: An int, the person's age.
    """
    def __init__(self, name, age):
        self.name = name
        self.age = age

复制代码# If the sign is a stop sign
if sign.color == 'red' and sign.sides == 8:
    stop()

复制代码def is_stop_sign(sign):
    return sign.color == 'red' and sign.sides == 8

if is_stop_sign(sign):
    stop()

复制代码wiki = (
    "The Colt Python is a .357 Magnum caliber revolver formerly manufactured "
    "by Colt's Manufacturing Company of Hartford, Connecticut. It is sometimes "
    'referred to as a "Combat Magnum". It was first introduced in 1955, the '
    "same year as Smith & Wesson's M29 .44 Magnum."
)

复制代码import unittest
import factories

class PersonTest(unittest.TestCase):
    def setUp(self):
        self.person = factories.PersonFactory()

    def test_has_age_in_dog_years(self):
        self.assertEqual(self.person.dog_years, self.person.age / 7)

复制代码import unittest

class TestAUser(unittest.TestCase):

    def test_can_write_a_blog_post(self):
        # Goes to the her dashboard
        ...
        # Clicks "New Post"
        ...
        # Fills out the post form
        ...
        # Clicks "Submit"
        ...
        # Can see the new post
        ...

复制代码class SubThread extends  Thread{
    @Override
    public void run() {
       //具体需要完成的业务代码
    }
}
SubThread subThread=new SubThread();//创建实例
subThread.start();//线程启动

复制代码class SubThread implements Runnable{//创建一个实现Runnable接口的类
    @Override
    public void run() {//实现run方法
     //你的业务代码
    }
}
SubThread subThread1=new SubThread();//创建一个实例
Thread t1=new Thread(subThread1);//把实例当参数传递给Thread构造方法 //得到一个线程实例
t1.start();//调用线程实例的start方法

复制代码Thread.currentThread() //获取当前线程
//以下都是线程实例上的方法
setName(); //设置线程名字
getName(); //获取线程名字
yield();//显示释放cpu的执行权  
join();//在一个线程执行中调用另一个目标线程的join方法，意味着立马执行目标线程，且执行完毕才回到原线程
isAlive();//判断当前线程是否还存活
sleep();//显示的让线程睡眠
setPriority() //设置当前线程的优先级
getPriority()//获取当前线程的优先级

复制代码class Window extends  Thread{//继承
    static int ticket=100;
    @Override
    public void run() {
        while (true){
            if(ticket>0){
                System.out.println(Thread.currentThread().getName()+"售票：票号为："+ ticket--);
            }else{
                break;
            }
        }
    }
}
//创建三个线程实例
Window w1=new Window();
Window w2=new Window();
Window w3=new Window();
w1.setName("窗口1");
w2.setName("窗口2");
w3.setName("窗口3");
w1.start();
w2.start();
w3.start();

复制代码class Window implements Runnable{//实现接口
    int ticket=100;
    @Override
    public void run() {
        while (true){
            if(ticket>0){
                System.out.println(Thread.currentThread().getName()+"售票：票号为："+ ticket--);
            }else{
                break;
            }
        }
    }
}

//构建三个线程实例
Window w=new Window();
Thread t1=new Thread(w);
Thread t2=new Thread(w);
Thread t3=new Thread(w);
t1.setName("窗口1");
t2.setName("窗口2");
t3.setName("窗口3");
t1.start();
t2.start();
t3.start();

复制代码    <groupId>com.github.Dorae132</groupId>
<artifactId>easyutil.easyexcel</artifactId>
<version>1.1.0</version>

复制代码ExcelUtils.excelRead(ExcelProperties.produceReadProperties("C:\\Users\\Dorae\\Desktop\\ttt\\",
			"append_0745704108fa42ffb656aef983229955.xlsx"), new IRowConsumer<String>() {
				@Override
				public void consume(List<String> row) {
					System.out.println(row);
					count.incrementAndGet();
					try {
						TimeUnit.MICROSECONDS.sleep(100);
					} catch (InterruptedException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
				}
			}, new IReadDoneCallBack<Void>() {
				@Override
				public Void call() {
					System.out.println(
							"end, count: " + count.get() + "\ntime: " + (System.currentTimeMillis() - start));
					return null;
				}
			}, 3, true);

复制代码public static void excelRead(IHandlerContext context, IRowConsumer rowConsumer, IReadDoneCallBack callBack,
		int threadCount, boolean syncCurrentThread) throws Exception {
	// synchronized main thread
	CyclicBarrier cyclicBarrier = null;
	threadCount = syncCurrentThread ? ++threadCount : threadCount;
	if (callBack != null) {
		cyclicBarrier = new CyclicBarrier(threadCount, () -> {
			callBack.call();
		});
	} else {
		cyclicBarrier = new CyclicBarrier(threadCount);
	}
	for (int i = 0; i < threadCount; i++) {
		THREADPOOL.execute(new ConsumeRowThread(context, rowConsumer, cyclicBarrier));
	}
	context.process();
	if (syncCurrentThread) {
		cyclicBarrier.await();
	}
}

复制代码from functools import wraps

import cProfile
from line_profiler import LineProfiler

import time


def func_time(f):
    """
    简单记录执行时间
    :param f:
    :return:
    """

    @wraps(f)
    def wrapper(*args, **kwargs):
        start = time.time()
        result = f(*args, **kwargs)
        end = time.time()
        print f.__name__, 'took', end - start, 'seconds'
        return result

    return wrapper


def func_cprofile(f):
    """
    内建分析器
    """

    @wraps(f)
    def wrapper(*args, **kwargs):
        profile = cProfile.Profile()
        try:
            profile.enable()
            result = f(*args, **kwargs)
            profile.disable()
            return result
        finally:
            profile.print_stats(sort='time')

    return wrapper



try:
    from line_profiler import LineProfiler


    def func_line_time(follow=[]):
        """
        每行代码执行时间详细报告
        :param follow: 内部调用方法
        :return:
        """
        def decorate(func):
            @wraps(func)
            def profiled_func(*args, **kwargs):
                try:
                    profiler = LineProfiler()
                    profiler.add_function(func)
                    for f in follow:
                        profiler.add_function(f)
                    profiler.enable_by_count()
                    return func(*args, **kwargs)
                finally:
                    profiler.print_stats()

            return profiled_func

        return decorate

except ImportError:
    def func_line_time(follow=[]):
        "Helpful if you accidentally leave in production!"
        def decorate(func):
            @wraps(func)
            def nothing(*args, **kwargs):
                return func(*args, **kwargs)

            return nothing

        return decorate

复制代码def test():
    for x in range(10000000):
        print x

复制代码@func_time
def test():
    for x in range(10000000):
        print x
# 输出
test took 6.10190296173 seconds

复制代码@func_cprofile
def test():
 for x in range(10000000):
     print x
# 输出
      3 function calls in 6.249 seconds

Ordered by: internal time

ncalls  tottime  percall  cumtime  percall filename:lineno(function)
     1    6.022    6.022    6.249    6.249 test.py:41(test)
     1    0.227    0.227    0.227    0.227 {range}
     1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}

复制代码@func_line_time()
def test():
    for x in range(10000000):
        print x
# 输出
Timer unit: 1e-06 s

Total time: 14.4183 s
File: /xx/test.py
Function: test at line 41

Line #      Hits         Time  Per Hit   % Time  Line Contents
==============================================================
    41                                           @func_line_time()
    42                                           def test():
    43  10000001    4031936.0      0.4     28.0      for x in range(10000000):
    44  10000000   10386347.0      1.0     72.0          print x

复制代码postgres=# create database blog;
CREATE DATABASE

postgres=# \c blog;
blog=#

复制代码CREATE TABLE posts (
    id              SERIAL,
    body            text,
    title           varchar(80)
);

CREATE TABLE tags (
    id              SERIAL,
    name            varchar(80)
);

CREATE TABLE tags_posts (
    id              SERIAL,
    tag_id          integer,
    post_id         integer
);

复制代码-- 填充文章数据
INSERT INTO posts (body, title) VALUES ('Hello Ruby', 'Ruby');
INSERT INTO posts (body, title) VALUES ('Hello Docker', 'Docker');

-- 填充标签数据
INSERT INTO tags (name) VALUES ('language');
INSERT INTO tags (name) VALUES ('container');
INSERT INTO tags (name) VALUES ('tech');

-- 为相关资源打上标签
INSERT INTO tags_posts (tag_id, post_id) VALUES ((SELECT id FROM tags WHERE name = 'container'), (SELECT id FROM posts WHERE title = 'Docker'));
INSERT INTO tags_posts (tag_id, post_id) VALUES ((SELECT id FROM tags WHERE name = 'tech'), (SELECT id FROM posts WHERE title = 'Docker'));
INSERT INTO tags_posts (tag_id, post_id) VALUES ((SELECT id FROM tags WHERE name = 'tech'), (SELECT id FROM posts WHERE title = 'Ruby'));
INSERT INTO tags_posts (tag_id, post_id) VALUES ((SELECT id FROM tags WHERE name = 'language'), (SELECT id FROM posts WHERE title = 'Ruby'));

复制代码blog=# SELECT tags.name FROM tags, posts, tags_posts WHERE tags.id = tags_posts.tag_id AND posts.id = tags_posts.post_id AND posts.title = 'Ruby';
   name
----------
 language
 tech
(2 rows)

blog=# SELECT tags.name FROM tags, posts, tags_posts WHERE tags.id = tags_posts.tag_id AND posts.id = tags_posts.post_id AND posts.title = 'Docker';
   name
-----------
 container
 tech
(2 rows)

复制代码naive_development=# select id, tag_id, taggable_type, taggable_id from taggings;
 id | tag_id |    taggable_type     | taggable_id
----+--------+----------------------+-------------
  1 |      1 | Refinery::Blog::Post |           1
  2 |      2 | Refinery::Blog::Post |           1
  3 |      3 | Refinery::Blog::Post |           1

复制代码ALTER TABLE tags_posts ADD COLUMN type varchar(80);
ALTER TABLE tags_posts RENAME TO taggings;
ALTER TABLE taggings RENAME COLUMN post_id TO taggable_id;
UPDATE taggings SET type='post';

复制代码-- 创建简单的用户表
CREATE TABLE users (
    id              SERIAL,
    username        varchar(80),
    age             integer
);


-- 添加一个名为lan的用户，并添加两个相关的标签

INSERT INTO users (username, age) values ('lan', 26);

INSERT INTO tags (name) VALUES ('student');
INSERT INTO tags (name) VALUES ('programmer');

复制代码INSERT INTO taggings (tag_id, taggable_id, type) VALUES ((SELECT id FROM tags WHERE name = 'student'), (SELECT id FROM users WHERE username = 'lan'), 'user');

INSERT INTO taggings (tag_id, taggable_id, type) VALUES ((SELECT id FROM tags WHERE name = 'programmer'), (SELECT id FROM users WHERE username = 'lan'), 'user');

复制代码blog=# SELECT tags.name FROM tags, users, taggings WHERE tags.id = taggings.tag_id AND users.id = taggings.taggable_id AND taggings.type = 'user' AND users.username = 'lan';

    name
------------
 student
 programmer
(2 rows)

复制代码blog=# SELECT tags.name FROM tags, posts, taggings WHERE tags.id = taggings.tag_id AND posts.id = taggings.taggable_id AND taggings.type = 'post' AND posts.title = 'Ruby';

   name
----------
 language
 tech

复制代码func main() {
	conent,err:=ioutil.ReadFile("filepath")
	if err !=nil{
		//错误处理
	}else {
		fmt.Println(string(conent))
	}
}

复制代码// The error built-in interface type is the conventional interface for
// representing an error condition, with the nil value representing no error.
type error interface {
	Error() string
}

复制代码type fileError struct {
}

func (fe *fileError) Error() string {
	return "文件错误"
}

复制代码func main() {
	conent, err := openFile()
	if err != nil {
		fmt.Println(err)
	} else {
		fmt.Println(string(conent))
	}
}

//只是模拟一个错误
func openFile() ([]byte, error) {
	return nil, &fileError{}
}

复制代码type fileError struct {
	s string
}

func (fe *fileError) Error() string {
	return fe.s
}

复制代码//只是模拟一个错误
func openFile() ([]byte, error) {
	return nil, &fileError{"文件错误，自定义"}
}

复制代码//blog:www.flysnow.org
//wechat:flysnow_org
func New(text string) error {
	return &errorString{text}
}

type errorString struct {
	s string
}

func (e *errorString) Error() string {
	return e.s
}

复制代码type stack []uintptr
type errorString struct {
	s string
	*stack
}

复制代码//blog:www.flysnow.org
//wechat:flysnow_org

func callers() *stack {
	const depth = 32
	var pcs [depth]uintptr
	n := runtime.Callers(3, pcs[:])
	var st stack = pcs[0:n]
	return &st
}

func New(text string) error {
	return &errorString{
		s:   text,
		stack: callers(),
	}
}

复制代码type withMessage struct {
	cause error
	msg   string
}

func WithMessage(err error, message string) error {
	if err == nil {
		return nil
	}
	return &withMessage{
		cause: err,
		msg:   message,
	}
}

复制代码func New(message string) error

复制代码//只附加新的信息
func WithMessage(err error, message string) error

//只附加调用堆栈信息
func WithStack(err error) error

//同时附加堆栈和信息
func Wrap(err error, message string) error

复制代码func Cause(err error) error {
	type causer interface {
		Cause() error
	}

	for err != nil {
		cause, ok := err.(causer)
		if !ok {
			break
		}
		err = cause.Cause()
	}
	return err
}

复制代码%s,%v //功能一样，输出错误信息，不包含堆栈
%q //输出的错误信息带引号，不包含堆栈
%+v //输出错误信息和堆栈

复制代码package com.yuloran;

import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

    public static void main(String[] args) throws ParserConfigurationException, IOException, SAXException, TransformerException {

        // 1. 解析
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder documentBuilder = factory.newDocumentBuilder();
        Document document = documentBuilder.parse(new InputSource(new InputStreamReader(new FileInputStream("strings.xml"), "UTF-8")));

        // 2. 遍历
        NodeList strings = document.getElementsByTagName("string");
        for (int i = 0; i < strings.getLength(); i++) {
            Node item = strings.item(i);
            System.out.print(String.format("Element:[tag:%s, content:%s] ", item.getNodeName(), item.getTextContent()));
            NamedNodeMap attributes = item.getAttributes();
            for (int j = 0; j < attributes.getLength(); j++) {
                Node attr = attributes.item(j);
                System.out.println(String.format("Attr:[key:%s, value:%s]", attr.getNodeName(), attr.getNodeValue()));
            }
        }

        // 3. 保存
        Transformer transformer = TransformerFactory.newInstance().newTransformer();
        transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
        transformer.setOutputProperty(OutputKeys.INDENT, "yes");
        transformer.transform(new DOMSource(document), new StreamResult("strings_copy.xml"));
    }

}

复制代码package com.yuloran;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Node;
import org.dom4j.io.SAXReader;
import org.xml.sax.InputSource;

import java.io.*;
import java.util.List;

public class Main {

    public static void main(String[] args) throws DocumentException, IOException {
        // 1. 解析
        SAXReader reader = new SAXReader();
        Document document = reader.read(new InputSource(new InputStreamReader(new FileInputStream("strings.xml"), "UTF-8")));

        // 2. 遍历
        List<Node> list = document.selectNodes("/resources/string[@name]");
        for (Node node : list) {
            System.out.print(String.format("Element:[tag:%s, content:%s] ", node.getName(), node.getText()));
            System.out.println(String.format("Attr:[name@%s]", node.valueOf("@name")));
        }

        // 3.保存
        OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream("strings_dom4j.xml"), "UTF-8");
        XMLWriter xmlWriter = new XMLWriter(writer);
        // 忽略 Element 对象中的转义字符
        xmlWriter.setEscapeText(false);
        xmlWriter.write(document);
        xmlWriter.close();
    }

}

复制代码        reader.setXMLFilter(new XMLFilterImpl() {
            @Override
            public void characters(char[] ch, int start, int length) throws SAXException {
                String text = new String(ch, start, length);
                System.out.println("text is: " + text);

                if (length == 1) {
                    if ((int) ch[0] == 160) {
                        char[] escape = " ".toCharArray();
                        super.characters(escape, 0, escape.length);
                        return;
                    }
                }

                super.characters(ch, start, length);
            }
        });

复制代码        // 3.保存
        OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream("strings_dom4j.xml"), "UTF-8");
        XMLWriter xmlWriter = new XMLWriter(writer);
        xmlWriter.setEscapeText(false);
        xmlWriter.write(document);
        xmlWriter.close();

复制代码static final int INITIALIZING = 0;     // Not yet created.
static final int CREATED = 1;          // Created.
static final int ACTIVITY_CREATED = 2; // The activity has finished its creation.
static final int STOPPED = 3;          // Fully created, not started.
static final int STARTED = 4;          // Created and started, not resumed.
static final int RESUMED = 5;          // Created started and resumed.

复制代码@SuppressWarnings("ReferenceEquality")
@Override
public Object instantiateItem(ViewGroup container, int position) {
    //...
    final long itemId = getItemId(position);

    // Do we already have this fragment?
    String name = makeFragmentName(container.getId(), itemId);
    Fragment fragment = mFragmentManager.findFragmentByTag(name);
    if (fragment != null) {
        //如果已经存在Fragment实例
        //那么使用attach操作进行添加
        mCurTransaction.attach(fragment);
    } else {
        //Fragment实例还没创建，通过getItem创建一个实例
        //然后通过add操作添加
        fragment = getItem(position);
        mCurTransaction.add(container.getId(), fragment,
                makeFragmentName(container.getId(), itemId));
    }
    //...
    return fragment;
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
    if (mCurTransaction == null) {
        mCurTransaction = mFragmentManager.beginTransaction();
    }
    //...
    //使用detach销毁Fragment
    mCurTransaction.detach((Fragment)object);
}

复制代码public void show(FragmentManager manager, String tag) {
    mDismissed = false;
    mShownByMe = true;
    FragmentTransaction ft = manager.beginTransaction();
    //核心操作
    ft.add(this, tag);
    ft.commit();
}


void dismissInternal(boolean allowStateLoss) {
    //...
    if (mBackStackId >= 0) {
        //...
    } else {
        FragmentTransaction ft = getFragmentManager().beginTransaction();
        //核心操作
        ft.remove(this);
        if (allowStateLoss) {
            ft.commitAllowingStateLoss();
        } else {
            ft.commit();
        }
    }
}

复制代码//FragmentManager.java
public View onCreateView(View parent, String name, Context context, AttributeSet attrs) {
    //判断是否是Fragment标签
    if (!"fragment".equals(name)) {
        return null;
    }

    //下面这些代码是获取xml中定义的
    //Fragment的一些信息
    //如类名(全路径)、id、tag
    String fname = attrs.getAttributeValue(null, "class");
    TypedArray a =  context.obtainStyledAttributes(attrs, FragmentTag.Fragment);
    if (fname == null) {
        fname = a.getString(FragmentTag.Fragment_name);
    }
    int id = a.getResourceId(FragmentTag.Fragment_id, View.NO_ID);
    String tag = a.getString(FragmentTag.Fragment_tag);
    a.recycle();

    //检查指定的Fragment类是否派生子Fragment
    if (!Fragment.isSupportFragmentClass(mHost.getContext(), fname)) {
        return null;
    }
    
    //必须满足id不为空或者tag不为空或者包裹Fragment的Container的id不为空
    //否则抛出异常
    int containerId = parent != null ? parent.getId() : 0;
    if (containerId == View.NO_ID && id == View.NO_ID && tag == null) {
        throw new IllegalArgumentException(attrs.getPositionDescription()
                + ": Must specify unique android:id, android:tag, or have a parent with an id for " + fname);
    }

    // If we restored from a previous state, we may already have
    // instantiated this fragment from the state and should use
    // that instance instead of making a new one.
    Fragment fragment = id != View.NO_ID ? findFragmentById(id) : null;
    if (fragment == null && tag != null) {
        fragment = findFragmentByTag(tag);
    }
    if (fragment == null && containerId != View.NO_ID) {
        fragment = findFragmentById(containerId);
    }

    //log...
    
    //通过反射创建Fragment实例
    if (fragment == null) {
        fragment = Fragment.instantiate(context, fname);
        //这个字段标志该Fragment实例是来自于xml文件
        fragment.mFromLayout = true;
        fragment.mFragmentId = id != 0 ? id : containerId;
        fragment.mContainerId = containerId;
        fragment.mTag = tag;
        fragment.mInLayout = true;
        fragment.mFragmentManager = this;
        fragment.mHost = mHost;
        fragment.onInflate(mHost.getContext(), attrs, fragment.mSavedFragmentState);
        //重点方法
        //第二个参数名为moveToStateNow
        //此处为true，因此该Fragment将会立即
        //迁移到当前FragmentManager所记录的状态
        //通常我们在onCreate方法中设置layout
        //因此通常来讲此时FragmentManager
        //处于CREATED状态
        addFragment(fragment, true);

    } else if (fragment.mInLayout) {
        //...
    } else {
        //...
    }

    if (mCurState < Fragment.CREATED && fragment.mFromLayout) {
        //如果当前FragmentManager处于INITIALIZING状态
        //那么强制将该Fragment迁移至CREATED状态
        moveToState(fragment, Fragment.CREATED, 0, 0, false);
    } else {
        //如果此时FragmentManager的状态大于CREATED
        //那么将该Fragment迁移至对应的状态
        moveToState(fragment);
    }

    //...
    return fragment.mView;
}

复制代码void moveToState(Fragment f, int newState, int transit, int transitionStyle,
            boolean keepActive) {
            
    //...
     switch (f.mState) {
        case Fragment.INITIALIZING:
            //...
        case Fragment.CREATED:
            //...
            //下面这个if语句来自于ensureInflatedFragmentView方法
            //为了方便，这里直接贴上了该方法的代码
            //如果该Fragment来自于布局文件
            //那么触发onCreateView创建试图实例
             if (f.mFromLayout && !f.mPerformedCreateView) {
                f.mView = f.performCreateView(f.performGetLayoutInflater(
                        f.mSavedFragmentState), null, f.mSavedFragmentState);
                if (f.mView != null) {
                    f.mInnerView = f.mView;
                    f.mView.setSaveFromParentEnabled(false);
                    if (f.mHidden) f.mView.setVisibility(View.GONE);
                    f.onViewCreated(f.mView, f.mSavedFragmentState);
                    dispatchOnFragmentViewCreated(f, f.mView, f.mSavedFragmentState, false);
                } else {
                    f.mInnerView = null;
                }
            }
            if (newState > Fragment.CREATED) {
                //...
            }
        //...
     }
    //...

}

复制代码public class DemoActivity extends FragmentActivity{
    protected void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.demo);
        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        ft.add(R.id.container, new DemoFragment());
        ft.commit();
    }
}

复制代码//FragmentTransaction的实现类为BackStackRecord
//action的实际类型是BackStackRecord
public void enqueueAction(OpGenerator action, boolean allowStateLoss) {
        if (!allowStateLoss) {
            checkStateLoss();
        }
        synchronized (this) {
            //...
            mPendingActions.add(action);
            synchronized (this) {
                boolean postponeReady =
                        mPostponedTransactions != null && !mPostponedTransactions.isEmpty();
                boolean pendingReady = mPendingActions != null && mPendingActions.size() == 1;
                if (postponeReady || pendingReady) {
                    //重点
                    //getHandler拿到的是一个主线程的Handler
                    //这里没有直接调用moveToState，而是抛了一个
                    //消息至消息队列，这将导致Fragment的状态迁移被延后
                    mHost.getHandler().removeCallbacks(mExecCommit);
                    mHost.getHandler().post(mExecCommit);
                }
            }
        }
    }

复制代码protected void onStart() {
    super.onStart();
    //...
    
    //敲黑板
    mFragments.execPendingActions();

    //...

    mFragments.dispatchStart();
    //...
}

javascript复制代码this === window // true
'use strict'
this === window;
this.name = '若川';
console.log(this.name); // 若川

javascript复制代码// 非严格模式
var name = 'window';
var doSth = function(){
    console.log(this.name);
}
doSth(); // 'window'

javascript复制代码// 非严格模式
let name2 = 'window2';
let doSth2 = function(){
    console.log(this === window);
    console.log(this.name2);
}
doSth2() // true, undefined

javascript复制代码// 严格模式
'use strict'
var name = 'window';
var doSth = function(){
    console.log(typeof this === 'undefined');
    console.log(this.name);
}
doSth(); // true，// 报错，因为this是undefined

ini复制代码doSth.call(undefined);
doSth.apply(undefined);

javascript复制代码var name = '若川';
setTimeout(function(){
    console.log(this.name);
}, 0);
// 语法
setTimeout(fn | code, 0, arg1, arg2, ...)
// 也可以是一串代码。也可以传递其他函数
// 类比 setTimeout函数内部调用fn或者执行代码`code`。
fn.call(undefined, arg1, arg2, ...);

javascript复制代码var name = 'window';
var doSth = function(){
    console.log(this.name);
}
var student = {
    name: '若川',
    doSth: doSth,
    other: {
        name: 'other',
        doSth: doSth,
    }
}
student.doSth(); // '若川'
student.other.doSth(); // 'other'
// 用call类比则为：
student.doSth.call(student);
// 用call类比则为：
student.other.doSth.call(student.other);

ini复制代码var studentDoSth = student.doSth;
studentDoSth(); // 'window'
// 用call类比则为：
studentDoSth.call(undefined);

kotlin复制代码fun.call(thisArg, arg1, arg2, ...)

javascript复制代码var doSth = function(name){
    console.log(this);
    console.log(name);
}
doSth.call(2, '若川'); // Number{2}, '若川'
var doSth2 = function(name){
    'use strict';
    console.log(this);
    console.log(name);
}
doSth2.call(2, '若川'); // 2, '若川'

javascript复制代码function Student(name){
    this.name = name;
    console.log(this); // {name: '若川'}
    // 相当于返回了
    // return this;
}
var result = new Student('若川');

sql复制代码function Student(name){
    this.name = name;
    // return function f(){};
    // return {};
}
var result = new Student('若川');
console.log(result); {name: '若川'}
// 如果返回函数f，则result是函数f，如果是对象{}，则result是对象{}

javascript复制代码function Student(name){
    this.name = name;
}
var s1 = new Student('若川');
Student.prototype.doSth = function(){
    console.log(this.name);
}
s1.doSth(); // '若川'

javascript复制代码class Student{
    constructor(name){
        this.name = name;
    }
    doSth(){
        console.log(this.name);
    }
}
let s1 = new Student('若川');
s1.doSth();

javascript复制代码'use strict';

var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

var Student = function () {
    function Student(name) {
        _classCallCheck(this, Student);

        this.name = name;
    }

    _createClass(Student, [{
        key: 'doSth',
        value: function doSth() {
            console.log(this.name);
        }
    }]);

    return Student;
}();

var s1 = new Student('若川');
s1.doSth();

ini复制代码var name = 'window';
var student = {
    name: '若川',
    doSth: function(){
        // var self = this;
        var arrowDoSth = () => {
            // console.log(self.name);
            console.log(this.name);
        }
        arrowDoSth();
    },
    arrowDoSth2: () => {
        console.log(this.name);
    }
}
student.doSth(); // '若川'
student.arrowDoSth2(); // 'window'

javascript复制代码var student = {
    name: '若川',
    doSth: function(){
        console.log(this.name);
        return () => {
            console.log('arrowFn:', this.name);
        }
    }
}
var person = {
    name: 'person',
}
student.doSth().call(person); // '若川'  'arrowFn:' '若川'
student.doSth.call(person)(); // 'person' 'arrowFn:' 'person'

xml复制代码<button class="button">onclick</button>
<ul class="list">
    <li>1</li>
    <li>2</li>
    <li>3</li>
</ul>
<script>
    var button = document.querySelector('button');
    button.onclick = function(ev){
        console.log(this);
        console.log(this === ev.currentTarget); // true
    }
    var list = document.querySelector('.list');
    list.addEventListener('click', function(ev){
        console.log(this === list); // true
        console.log(this === ev.currentTarget); // true
        console.log(this);
        console.log(ev.target);
    }, false);
</script>

ini复制代码<button class="btn1" onclick="console.log(this === document.querySelector('.btn1'))">点我呀</button>
<button onclick="console.log((function(){return this})());">再点我呀</button>

javascript复制代码var name = 'window';
var person = {
    name: 'person',
}
var doSth = function(){
    console.log(this.name);
    return function(){
        console.log('return:', this.name);
    }
}
var Student = {
    name: '若川',
    doSth: doSth,
}
// 普通函数调用
doSth(); // window
// 对象上的函数调用
Student.doSth(); // '若川'
// call、apply 调用
Student.doSth.call(person); // 'person'
new Student.doSth.call(person);

kotlin复制代码Uncaught TypeError: Student.doSth.call is not a constructor