巨应打字员


```Python
import datetime
import time

def wait(timeout_ms, calback=None):
    '''等待指定时间

    Arguments:
        timeout_ms {[type]} -- [等待指定毫秒数]

    Keyword Arguments:
        calback {[type]} -- [每一秒触发一次回调，回调参数是剩余的秒数] (default: {None})
    '''

    now = datetime.datetime.now()
    endTime = now+datetime.timedelta(milliseconds=timeout_ms)
    timespane = endTime-now
    while timespane.seconds > 0:
        if(calback is not None):
            calback(timespane.seconds)
        now = datetime.datetime.now()
        timespane = endTime-now
        time.sleep(1)

def callback(remain_seconds):
    print("剩余", remain_seconds)

wait(5, callback)
print('end')
```

输出结果：
剩余 5
剩余 4
剩余 3
剩余 2
剩余 1
end


<pre><code>import datetime
import time

def wait(timeout_ms, calback=None):
    '''等待指定时间

    Arguments:
        timeout_ms {[type]} -- [等待指定毫秒数]

    Keyword Arguments:
        calback {[type]} -- [每一秒触发一次回调，回调参数是剩余的秒数] (default: {None})
    '''

    now = datetime.datetime.now()
    endTime = now+datetime.timedelta(milliseconds=timeout_ms)
    timespane = endTime-now
    while timespane.seconds > 0:
        if(calback is not None):
            calback(timespane.seconds)
        now = datetime.datetime.now()
        timespane = endTime-now
        time.sleep(1)

def callback(remain_seconds):
    print("剩余", remain_seconds)

wait(5, callback)
print('end')
</code></pre>
<p>输出结果：
剩余 5
剩余 4
剩余 3
剩余 2
剩余 1
end</p>


Python 时间运算

Node 实用工具之 NVM，兼容多个 Node，一键切换版本。

---

## 安装

### Ubuntu

```shell
curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.34.0/install.sh | bash
```

或者

```shell
wget -qO- https://raw.githubusercontent.com/creationix/nvm/v0.34.0/install.sh | bash
```

安装后执行 nvm，如果返回 nvm: command not found，重启终端解决。

### Windows

下载地址：
https://github.com/coreybutler/nvm-windows/releases

## 用法

### 查看已安装版本

```shell
nvm ls
```

### 安装新版本

```shell
nvm install 10.15.3
```

### 切换 node 版本

```shell
nvm use 10.15.3
```



<p>Node 实用工具之 NVM，兼容多个 Node，一键切换版本。</p>
<hr>
<h2>安装</h2>
<h3>Ubuntu</h3>
<pre><code>curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.34.0/install.sh | bash
</code></pre>
<p>或者</p>
<pre><code>wget -qO- https://raw.githubusercontent.com/creationix/nvm/v0.34.0/install.sh | bash
</code></pre>
<p>安装后执行 nvm，如果返回 nvm: command not found，重启终端解决。</p>
<h3>Windows</h3>
<p>下载地址：
https://github.com/coreybutler/nvm-windows/releases</p>
<h2>用法</h2>
<h3>查看已安装版本</h3>
<pre><code>nvm ls
</code></pre>
<h3>安装新版本</h3>
<pre><code>nvm install 10.15.3
</code></pre>
<h3>切换 node 版本</h3>
<pre><code>nvm use 10.15.3
</code></pre>


NVM 一键切换Node版本


##### 概要：

曾经 UWP 只能读写当前应用的存储目录。  
2018 年微软开放了一种更广泛的 IO 读写权限，使 UWP 可以像传统应用程序一样读写几乎所有目录。让 UWP 的能力更上一层楼。

[相关连接](https://blogs.windows.com/buildingapps/2018/02/23/windows-community-standup-discussing-multi-instancing-console-uwps-broader-file-system-access/#lDQ5SHeBiXKQsbHM.97)

##### 如何开启：

打开 Package.appxmanifest。
添加命名空间 rescap，并将其添加到 IgnorableNamespaces：

```xml
<Package
  ...
  xmlns:rescap="http://schemas.microsoft.com/appx/manifest/foundation/windows10/restrictedcapabilities"
  IgnorableNamespaces="uap mp uap5 rescap">
...
<Capabilities>
    <rescap:Capability Name="broadFileSystemAccess" />
</Capabilities>
```

##### 创建文件:

```CSharp
//写入文件
    string dir = "d:\\";
    string fileName = "sample.txt";
    string fullPath = Path.Combine(dir, fileName);
    StorageFolder storageFolder = await StorageFolder.GetFolderFromPathAsync(dir);
    StorageFile writeFile = await storageFolder.CreateFileAsync(fileName, CreationCollisionOption.ReplaceExisting);
    await FileIO.WriteTextAsync(writeFile, DateTime.Now.ToString());

    //读取文件
    StorageFile readFile = await storageFolder.GetFileAsync(fileName);

    //全路径读取
    //StorageFile readFile = await StorageFile.GetFileFromPathAsync(fullPath);
    var stream = await readFile.OpenAsync(FileAccessMode.Read);
    ulong size = stream.Size;
    using (var inputStream = stream.GetInputStreamAt(0))
    {
        using (var dataReader = new Windows.Storage.Streams.DataReader(inputStream))
        {
            uint numBytesLoaded = await dataReader.LoadAsync((uint)size);
            string text = dataReader.ReadString(numBytesLoaded);
        }
    }
```

测试发现系统盘根目录还是没有权限，其他目录可以。已经可以满足大多数需求了。


<h5>概要：</h5>
<p>曾经 UWP 只能读写当前应用的存储目录。  
2018 年微软开放了一种更广泛的 IO 读写权限，使 UWP 可以像传统应用程序一样读写几乎所有目录。让 UWP 的能力更上一层楼。</p>
<p><a href="https://blogs.windows.com/buildingapps/2018/02/23/windows-community-standup-discussing-multi-instancing-console-uwps-broader-file-system-access/#lDQ5SHeBiXKQsbHM.97">相关连接</a></p>
<h5>如何开启：</h5>
<p>打开 Package.appxmanifest。
添加命名空间 rescap，并将其添加到 IgnorableNamespaces：</p>
<pre><code>&#x3C;Package
  ...
  xmlns:rescap="http://schemas.microsoft.com/appx/manifest/foundation/windows10/restrictedcapabilities"
  IgnorableNamespaces="uap mp uap5 rescap">
...
&#x3C;Capabilities>
    &#x3C;rescap:Capability Name="broadFileSystemAccess" />
&#x3C;/Capabilities>
</code></pre>
<h5>创建文件:</h5>
<pre><code>//写入文件
    string dir = "d:\\";
    string fileName = "sample.txt";
    string fullPath = Path.Combine(dir, fileName);
    StorageFolder storageFolder = await StorageFolder.GetFolderFromPathAsync(dir);
    StorageFile writeFile = await storageFolder.CreateFileAsync(fileName, CreationCollisionOption.ReplaceExisting);
    await FileIO.WriteTextAsync(writeFile, DateTime.Now.ToString());

    //读取文件
    StorageFile readFile = await storageFolder.GetFileAsync(fileName);

    //全路径读取
    //StorageFile readFile = await StorageFile.GetFileFromPathAsync(fullPath);
    var stream = await readFile.OpenAsync(FileAccessMode.Read);
    ulong size = stream.Size;
    using (var inputStream = stream.GetInputStreamAt(0))
    {
        using (var dataReader = new Windows.Storage.Streams.DataReader(inputStream))
        {
            uint numBytesLoaded = await dataReader.LoadAsync((uint)size);
            string text = dataReader.ReadString(numBytesLoaded);
        }
    }
</code></pre>
<p>测试发现系统盘根目录还是没有权限，其他目录可以。已经可以满足大多数需求了。</p>
