我有一个Flask服务器通过端口5000运行，它很好。我可以在http://example.com:5000上访问它

但是是否可以通过http://example.com访问呢?我假设这意味着我必须将端口从5000更改为80。但是当我在Flask上尝试时，当我运行它时，我得到这个错误消息。

Traceback (most recent call last):
  File "xxxxxx.py", line 31, in <module>
app.run(host="0.0.0.0", port=int("80"), debug=True)
   File "/usr/local/lib/python2.6/dist-packages/flask/app.py", line 772, in run
run_simple(host, port, self, **options)
  File "/usr/local/lib/python2.6/dist-packages/werkzeug/serving.py", line 706, in run_simple
    test_socket.bind((hostname, port))
  File "<string>", line 1, in bind
socket.error: [Errno 98] Address already in use

运行lsof -i:80返回

COMMAND   PID     USER   FD   TYPE   DEVICE SIZE/OFF NODE NAME
apache2   467     root    3u  IPv4 92108840      0t0  TCP *:www (LISTEN)
apache2  4413 www-data    3u  IPv4 92108840      0t0  TCP *:www (LISTEN)
apache2 14346 www-data    3u  IPv4 92108840      0t0  TCP *:www (LISTEN)
apache2 14570 www-data    3u  IPv4 92108840      0t0  TCP *:www (LISTEN)
apache2 14571 www-data    3u  IPv4 92108840      0t0  TCP *:www (LISTEN)
apache2 14573 www-data    3u  IPv4 92108840      0t0  TCP *:www (LISTEN)

我需要先终止这些进程吗?这样安全吗?或者有没有另一种方法来保持Flask在端口5000上运行，但有主网站域名以某种方式重定向?

我试图使用android-support-v7:21库创建简单的应用程序。 代码片段: MainActivity.java

public class MainActivity extends ActionBarActivity {

    Toolbar mActionBarToolbar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mActionBarToolbar = (Toolbar) findViewById(R.id.toolbar_actionbar);            
        mActionBarToolbar.setTitle("My title");
        setSupportActionBar(mActionBarToolbar);
}

activity_main.xml

<LinearLayout
    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"
    android:fitsSystemWindows="true"
    android:orientation="vertical">

    <android.support.v7.widget.Toolbar            
        android:id="@+id/toolbar_actionbar"
        android:background="@null"
        android:layout_width="match_parent"
        android:layout_height="?actionBarSize"
        android:fitsSystemWindows="true" />

</LinearLayout>

但是工具栏上显示的不是“我的标题”%应用程序名称%。 似乎setTitle方法没有效果。 我想展示"我的头衔"

乌利希期刊指南: 在此之前，styles.xml是:

<style name="AppTheme" parent="Theme.AppCompat">
    <item name="windowActionBar">false</item>
</style>

我以为动作栏不用。 我添加了NoActionBar到父样式:

<style name="AppTheme" parent="Theme.AppCompat.NoActionBar">
    <item name="windowActionBar">false</item>
</style>

但问题并没有解决。

因为TCP保证数据包的传递，因此可以被认为是“可靠的”，而UDP不保证任何东西，数据包可能会丢失。在应用程序中使用UDP而不是TCP流传输数据的优势是什么?在什么情况下UDP是更好的选择，为什么?

我假设UDP更快，因为它没有创建和维护流的开销，但如果一些数据从未到达目的地，这不是无关紧要的吗?

I'm an iOS developer with some experience and this question is really interesting to me. I saw a lot of different resources and materials on this topic, but nevertheless I'm still confused. What is the best architecture for an iOS networked application? I mean basic abstract framework, patterns, which will fit every networking application whether it is a small app which only have a few server requests or a complex REST client. Apple recommends to use MVC as a basic architectural approach for all iOS applications, but neither MVC nor the more modern MVVM patterns explain where to put network logic code and how to organize it in general. Do I need to develop something like MVCS(S for Service) and in this Service layer put all API requests and other networking logic, which in perspective may be really complex? After doing some research I found two basic approaches for this. Here it was recommended to create a separate class for every network request to web-service API (like LoginRequest class or PostCommentRequest class and so on) which all inherits from the base request abstract class AbstractBaseRequest and in addition to create some global network manager which encapsulates common networking code and other preferences (it may be AFNetworking customisation or RestKit tuning, if the we have complex object mappings and persistence, or even an own network communication implementation with standard API). But this approach seems an overhead for me. Another approach is to have some singleton API dispatcher or manager class as in the first approach, but not to create classes for every request and instead to encapsulate every request as an instance public method of this manager class like: fetchContacts, loginUser methods, etc. So, what is the best and correct way? Are there other interesting approaches I don't know yet? And should I create another layer for all this networking stuff like Service, or NetworkProvider layer or whatever on top of my MVC architecture, or this layer should be integrated (injected) into existing MVC layers e.g. Model? I know there exists beautiful approaches, or how then such mobile monsters like Facebook client or LinkedIn client deal with exponentially growing complexity of networking logic? I know there are no exact and formal answer to the problem. The goal of this question is to collect the most interesting approaches from experienced iOS developers. The best suggested approach will be marked as accepted and awarded with a reputation bounty, others will be upvoted. It is mostly a theoretical and research question. I want to understand basic, abstract and correct architectural approach for networking applications in iOS. I hope for detailed explanation from experienced developers.

有没有一种方法可以从Windows命令行检查特定端口的状态?我知道我可以使用netstat来检查所有端口，但netstat很慢，而查看特定的端口可能不是。

是否有一种方法可以获得本地网络中所有有效IP地址的列表?

我指的是每个用户在网络中使用的所有IP地址。

我如何能看到什么是在S3桶与boto3?(例如，写一个“ls”)?

做以下事情:

import boto3
s3 = boto3.resource('s3')
my_bucket = s3.Bucket('some/path/')

返回:

s3.Bucket(name='some/path/')

我如何看到它的内容?

在互联网上有几个地方告诉你如何获得一个IP地址。很多都像这个例子:

String strHostName = string.Empty;
// Getting Ip address of local machine...
// First get the host name of local machine.
strHostName = Dns.GetHostName();
Console.WriteLine("Local Machine's Host Name: " + strHostName);
// Then using host name, get the IP address list..
IPHostEntry ipEntry = Dns.GetHostEntry(strHostName);
IPAddress[] addr = ipEntry.AddressList;

for (int i = 0; i < addr.Length; i++)
{
    Console.WriteLine("IP Address {0}: {1} ", i, addr[i].ToString());
}
Console.ReadLine();

在这个例子中，我得到了几个IP地址，但我只对路由器分配给运行程序的计算机的IP地址感兴趣:例如，如果某人希望访问我计算机中的共享文件夹，我将给他的IP地址。

如果我没有连接到网络，我直接通过没有路由器的调制解调器连接到互联网，那么我希望得到一个错误。我如何才能看到我的计算机是否连接到网络与c#，如果它是然后得到局域网IP地址。

我在我们的软件中有一个错误，当我收到连接超时时发生。这些错误是非常罕见的(通常是当我的连接被我们的内部网络丢弃时)。我怎样才能人为地产生这种效果来测试我们的软件呢?

如果重要，应用程序是用c++ /MFC编写的，使用CAsyncSocket类。

编辑:

我尝试使用一个不存在的主机，我得到套接字错误:

无效的参数

我的下一个尝试是使用Alexander的建议，连接到不同的端口，例如81(在我自己的服务器上)。这很有效。与断开连接完全相同(等待60秒，然后出错)。谢谢你！

我试图用相机拍照，但我得到以下错误:

FATAL EXCEPTION: main
Process: com.example.marek.myapplication, PID: 6747
java.lang.IllegalArgumentException: Failed to find configured root that contains /storage/emulated/0/Android/data/com.example.marek.myapplication/files/Pictures/JPEG_20170228_175633_470124220.jpg
    at android.support.v4.content.FileProvider$SimplePathStrategy.getUriForFile(FileProvider.java:711)
    at android.support.v4.content.FileProvider.getUriForFile(FileProvider.java:400)
    at com.example.marek.myapplication.MainActivity.dispatchTakePictureIntent(MainActivity.java:56)
    at com.example.marek.myapplication.MainActivity.access$100(MainActivity.java:22)
    at com.example.marek.myapplication.MainActivity$1.onClick(MainActivity.java:35)

AndroidManifest.xml:

<provider
        android:name="android.support.v4.content.FileProvider"
        android:authorities="com.example.marek.myapplication.fileprovider"
        android:enabled="true"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_paths" />
</provider>

Java:

Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    // Ensure that there's a camera activity to handle the intent
    if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
        // Create the File where the photo should go
        File photoFile = null;
        try {
            photoFile = createImageFile();
        } catch (IOException ex) {
            Toast.makeText(getApplicationContext(), "Error while saving picture.", Toast.LENGTH_LONG).show();
        }
        // Continue only if the File was successfully created
        if (photoFile != null) {
            Uri photoURI = FileProvider.getUriForFile(this,
                    "com.example.marek.myapplication.fileprovider",
                    photoFile);
            takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
            startActivityForResult(takePictureIntent, REQUEST_TAKE_PHOTO);
        }
    }

file_paths.xml

<?xml version="1.0" encoding="utf-8"?>
<paths>
    <files-path name="my_images" path="images/"/>
</paths>

我一整天都在搜索这个错误，试图理解FileProvider，但我不知道这个错误消息试图告诉我什么。如果你想要更多信息/代码，请在评论中告诉我。