Events01 示例
此示例演示如何创建一个 cmdlet，该 cmdlet 允许用户注册 由 System.IO.FileSystemWatcher 引发的事件。 通过此 cmdlet，用户可以注册特定目录下创建文件时要执行的操作。 此示例派生自 Microsoft.PowerShell.Commands.ObjectEventRegistrationBase 基类。
如何使用示例生成Visual Studio。
安装 Windows PowerShell 2.0 SDK 后，导航到 Events01 文件夹。 默认位置为
C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0\Samples\sysmgmt\WindowsPowerShell\csharp\Events01。双击解决方案 (.sln) 图标。 这会在 Microsoft Visual Studio 中打开示例项目。
在“生成”菜单中选择“生成解决方案” 。 示例的库将在默认 或 文件夹中
\bin\bin\debug生成。
如何运行示例
创建以下模块文件夹：
[user]/documents/windowspowershell/modules/events01将示例的库文件复制到模块文件夹。
启动 Windows PowerShell。
运行以下命令，将 cmdlet 加载到Windows PowerShell：
import-module events01使用 Register-FileSystemEvent cmdlet 注册在 TEMP 目录下创建文件时将写入消息的操作。
Register-FileSystemEvent $env:temp Created -filter "*.txt" -action { Write-Host "A file was created in the TEMP directory" }在 TEMP 目录下创建一个文件，请注意，该操作是在 (消息时执行的) 。
这是通过执行这些步骤获得的示例输出。
Id Name State HasMoreData Location Command
-- ---- ----- ----------- -------- -------
1 26932870-d3b... NotStarted False Write-Host "A f...
Set-Content $env:temp\test.txt "This is a test file"
A file was created in the TEMP directory
要求
此示例需要 Windows PowerShell 2.0。
演示
此示例演示了以下内容。
如何编写用于事件注册的 cmdlet
cmdlet 派生自 Microsoft.PowerShell.Commands.ObjectEventRegistrationBase 类，该类支持 Register-*Event cmdlet 通用的参数。 派生自 Microsoft.PowerShell.Commands.ObjectEventRegistrationBase 的 Cmdlet 只需定义其特定参数并重写 和 GetSourceObject GetSourceObjectEventName 抽象方法。
示例
此示例演示如何注册 System.IO.FileSystemWatcher 引发的事件。
namespace Sample
{
using System;
using System.IO;
using System.Management.Automation;
using System.Management.Automation.Runspaces;
using Microsoft.PowerShell.Commands;
[Cmdlet(VerbsLifecycle.Register, "FileSystemEvent")]
public class RegisterObjectEventCommand : ObjectEventRegistrationBase
{
/// <summary>The FileSystemWatcher that exposes the events.</summary>
private FileSystemWatcher fileSystemWatcher = new FileSystemWatcher();
/// <summary>Name of the event to which the cmdlet registers.</summary>
private string eventName = null;
/// <summary>
/// Gets or sets the path that will be monitored by the FileSystemWatcher.
/// </summary>
[Parameter(Mandatory = true, Position = 0)]
public string Path
{
get
{
return this.fileSystemWatcher.Path;
}
set
{
this.fileSystemWatcher.Path = value;
}
}
/// <summary>
/// Gets or sets the name of the event to which the cmdlet registers.
/// <para>
/// Currently System.IO.FileSystemWatcher exposes 6 events: Changed, Created,
/// Deleted, Disposed, Error, and Renamed. Check the documentation of
/// FileSystemWatcher for details on each event.
/// </para>
/// </summary>
[Parameter(Mandatory = true, Position = 1)]
public string EventName
{
get
{
return this.eventName;
}
set
{
this.eventName = value;
}
}
/// <summary>
/// Gets or sets the filter that will be user by the FileSystemWatcher.
/// </summary>
[Parameter(Mandatory = false)]
public string Filter
{
get
{
return this.fileSystemWatcher.Filter;
}
set
{
this.fileSystemWatcher.Filter = value;
}
}
/// <summary>
/// Derived classes must implement this method to return the object that generates
/// the events to be monitored.
/// </summary>
/// <returns> This sample returns an instance of System.IO.FileSystemWatcher</returns>
protected override object GetSourceObject()
{
return this.fileSystemWatcher;
}
/// <summary>
/// Derived classes must implement this method to return the name of the event to
/// be monitored. This event must be exposed by the input object.
/// </summary>
/// <returns> This sample returns the event specified by the user with the -EventName parameter.</returns>
protected override string GetSourceObjectEventName()
{
return this.eventName;
}
}
}