Process Class

Provides access to local and remote processes and enables you to start and stop local system processes.

To browse the .NET Framework source code for this type, see the Reference Source.

Namespace:  System.Diagnostics
Assembly:  System (in System.dll)

'Declaration
<HostProtectionAttribute(SecurityAction.LinkDemand, SharedState := True, Synchronization := True,  _
	ExternalProcessMgmt := True, SelfAffectingProcessMgmt := True)> _
<PermissionSetAttribute(SecurityAction.LinkDemand, Name := "FullTrust")> _
<PermissionSetAttribute(SecurityAction.InheritanceDemand, Name := "FullTrust")> _
Public Class Process _
	Inherits Component

The Process type exposes the following members.

  NameDescription
Public methodProcessInitializes a new instance of the Process class.
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  NameDescription
Public propertyBasePriorityGets the base priority of the associated process.
Protected propertyCanRaiseEventsGets a value indicating whether the component can raise an event. (Inherited from Component.)
Public propertyContainerGets the IContainer that contains the Component. (Inherited from Component.)
Protected propertyDesignModeGets a value that indicates whether the Component is currently in design mode. (Inherited from Component.)
Public propertyEnableRaisingEventsGets or sets whether the Exited event should be raised when the process terminates.
Protected propertyEventsGets the list of event handlers that are attached to this Component. (Inherited from Component.)
Public propertyExitCodeGets the value that the associated process specified when it terminated.
Public propertyExitTimeGets the time that the associated process exited.
Public propertyHandleGets the native handle of the associated process.
Public propertyHandleCountGets the number of handles opened by the process.
Public propertyHasExitedGets a value indicating whether the associated process has been terminated.
Public propertyIdGets the unique identifier for the associated process.
Public propertyMachineNameGets the name of the computer the associated process is running on.
Public propertyMainModuleGets the main module for the associated process.
Public propertyMainWindowHandleGets the window handle of the main window of the associated process.
Public propertyMainWindowTitleGets the caption of the main window of the process.
Public propertyMaxWorkingSetGets or sets the maximum allowable working set size for the associated process.
Public propertyMinWorkingSetGets or sets the minimum allowable working set size for the associated process.
Public propertyModulesGets the modules that have been loaded by the associated process.
Public propertyNonpagedSystemMemorySize Obsolete. Gets the nonpaged system memory size allocated to this process.
Public propertyNonpagedSystemMemorySize64Gets the amount of nonpaged system memory allocated for the associated process.
Public propertyPagedMemorySize Obsolete. Gets the paged memory size.
Public propertyPagedMemorySize64Gets the amount of paged memory allocated for the associated process.
Public propertyPagedSystemMemorySize Obsolete. Gets the paged system memory size.
Public propertyPagedSystemMemorySize64Gets the amount of pageable system memory allocated for the associated process.
Public propertyPeakPagedMemorySize Obsolete. Gets the peak paged memory size.
Public propertyPeakPagedMemorySize64Gets the maximum amount of memory in the virtual memory paging file used by the associated process.
Public propertyPeakVirtualMemorySize Obsolete. Gets the peak virtual memory size.
Public propertyPeakVirtualMemorySize64Gets the maximum amount of virtual memory used by the associated process.
Public propertyPeakWorkingSet Obsolete. Gets the peak working set size for the associated process.
Public propertyPeakWorkingSet64Gets the maximum amount of physical memory used by the associated process.
Public propertyPriorityBoostEnabledGets or sets a value indicating whether the associated process priority should temporarily be boosted by the operating system when the main window has the focus.
Public propertyPriorityClassGets or sets the overall priority category for the associated process.
Public propertyPrivateMemorySize Obsolete. Gets the private memory size.
Public propertyPrivateMemorySize64Gets the amount of private memory allocated for the associated process.
Public propertyPrivilegedProcessorTimeGets the privileged processor time for this process.
Public propertyProcessNameGets the name of the process.
Public propertyProcessorAffinityGets or sets the processors on which the threads in this process can be scheduled to run.
Public propertyRespondingGets a value indicating whether the user interface of the process is responding.
Public propertySessionIdGets the Terminal Services session identifier for the associated process.
Public propertySiteGets or sets the ISite of the Component. (Inherited from Component.)
Public propertyStandardErrorGets a stream used to read the error output of the application.
Public propertyStandardInputGets a stream used to write the input of the application.
Public propertyStandardOutputGets a stream used to read the output of the application.
Public propertyStartInfoGets or sets the properties to pass to the Start method of the Process.
Public propertyStartTimeGets the time that the associated process was started.
Public propertySynchronizingObjectGets or sets the object used to marshal the event handler calls that are issued as a result of a process exit event.
Public propertyThreadsGets the set of threads that are running in the associated process.
Public propertyTotalProcessorTimeGets the total processor time for this process.
Public propertyUserProcessorTimeGets the user processor time for this process.
Public propertyVirtualMemorySize Obsolete. Gets the size of the process's virtual memory.
Public propertyVirtualMemorySize64Gets the amount of the virtual memory allocated for the associated process.
Public propertyWorkingSet Obsolete. Gets the associated process's physical memory usage.
Public propertyWorkingSet64Gets the amount of physical memory allocated for the associated process.
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  NameDescription
Public methodBeginErrorReadLineBegins asynchronous read operations on the redirected StandardError stream of the application.
Public methodBeginOutputReadLineBegins asynchronous read operations on the redirected StandardOutput stream of the application.
Public methodCancelErrorReadCancels the asynchronous read operation on the redirected StandardError stream of an application.
Public methodCancelOutputReadCancels the asynchronous read operation on the redirected StandardOutput stream of an application.
Public methodCloseFrees all the resources that are associated with this component.
Public methodCloseMainWindowCloses a process that has a user interface by sending a close message to its main window.
Public methodCreateObjRefCreates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from MarshalByRefObject.)
Public methodDisposeReleases all resources used by the Component. (Inherited from Component.)
Protected methodDispose(Boolean)Infrastructure. Release all resources used by this process. (Overrides Component.Dispose(Boolean).)
Public methodStatic memberEnterDebugModePuts a Process component in state to interact with operating system processes that run in a special mode by enabling the native property SeDebugPrivilege on the current thread.
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodFinalizeReleases unmanaged resources and performs other cleanup operations before the Component is reclaimed by garbage collection. (Inherited from Component.)
Public methodStatic memberGetCurrentProcessGets a new Process component and associates it with the currently active process.
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetLifetimeServiceRetrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
Public methodStatic memberGetProcessById(Int32)Returns a new Process component, given the identifier of a process on the local computer.
Public methodStatic memberGetProcessById(Int32, String)Returns a new Process component, given a process identifier and the name of a computer on the network.
Public methodStatic memberGetProcessesCreates a new Process component for each process resource on the local computer.
Public methodStatic memberGetProcesses(String)Creates a new Process component for each process resource on the specified computer.
Public methodStatic memberGetProcessesByName(String)Creates an array of new Process components and associates them with all the process resources on the local computer that share the specified process name.
Public methodStatic memberGetProcessesByName(String, String)Creates an array of new Process components and associates them with all the process resources on a remote computer that share the specified process name.
Protected methodGetServiceReturns an object that represents a service provided by the Component or by its Container. (Inherited from Component.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodInitializeLifetimeServiceObtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
Public methodKillImmediately stops the associated process.
Public methodStatic memberLeaveDebugModeTakes a Process component out of the state that lets it interact with operating system processes that run in a special mode.
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Protected methodMemberwiseClone(Boolean)Creates a shallow copy of the current MarshalByRefObject object. (Inherited from MarshalByRefObject.)
Protected methodOnExitedRaises the Exited event.
Public methodRefreshDiscards any information about the associated process that has been cached inside the process component.
Public methodStartStarts (or reuses) the process resource that is specified by the StartInfo property of this Process component and associates it with the component.
Public methodStatic memberStart(ProcessStartInfo)Starts the process resource that is specified by the parameter containing process start information (for example, the file name of the process to start) and associates the resource with a new Process component.
Public methodStatic memberStart(String)Starts a process resource by specifying the name of a document or application file and associates the resource with a new Process component.
Public methodStatic memberStart(String, String)Starts a process resource by specifying the name of an application and a set of command-line arguments, and associates the resource with a new Process component.
Public methodStatic memberStart(String, String, SecureString, String)Starts a process resource by specifying the name of an application, a user name, a password, and a domain and associates the resource with a new Process component.
Public methodStatic memberStart(String, String, String, SecureString, String)Starts a process resource by specifying the name of an application, a set of command-line arguments, a user name, a password, and a domain and associates the resource with a new Process component.
Public methodToStringFormats the process's name as a string, combined with the parent component type, if applicable. (Overrides Component.ToString.)
Public methodWaitForExitInstructs the Process component to wait indefinitely for the associated process to exit.
Public methodWaitForExit(Int32)Instructs the Process component to wait the specified number of milliseconds for the associated process to exit.
Public methodWaitForInputIdleCauses the Process component to wait indefinitely for the associated process to enter an idle state. This overload applies only to processes with a user interface and, therefore, a message loop.
Public methodWaitForInputIdle(Int32)Causes the Process component to wait the specified number of milliseconds for the associated process to enter an idle state. This overload applies only to processes with a user interface and, therefore, a message loop.
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  NameDescription
Public eventDisposedOccurs when the component is disposed by a call to the Dispose method. (Inherited from Component.)
Public eventErrorDataReceivedOccurs when an application writes to its redirected StandardError stream.
Public eventExitedOccurs when a process exits.
Public eventOutputDataReceivedOccurs when an application writes to its redirected StandardOutput stream.
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NoteNote

To view the .NET Framework source code for this type, see the Reference Source. You can browse through the source code online, download the reference for offline viewing, and step through the sources (including patches and updates) during debugging; see instructions.

A Process component provides access to a process that is running on a computer. A process, in the simplest terms, is a running application. A thread is the basic unit to which the operating system allocates processor time. A thread can execute any part of the code of the process, including parts currently being executed by another thread.

The Process component is a useful tool for starting, stopping, controlling, and monitoring applications. Using the Process component, you can obtain a list of the processes that are running, or you can start a new process. A Process component is used to access system processes. After a Process component has been initialized, it can be used to obtain information about the running process. Such information includes the set of threads, the loaded modules (.dll and .exe files), and performance information such as the amount of memory the process is using.

This type implements the IDisposable interface. When you have finished using the type, you should dispose of it either directly or indirectly. To dispose of the type directly, call its Dispose method in a try/catch block. To dispose of it indirectly, use a language construct such as using (in C#) or Using (in Visual Basic). For more information, see the “Using an Object that Implements IDisposable” section in the IDisposable interface topic.

NoteNote

A 32-bit processes cannot access the modules of a 64-bit process. If you try to get information about a 64-bit process from a 32-bit process, you will get a Win32Exception exception.

If you have a path variable declared in your system using quotes, you must fully qualify that path when starting any process found in that location. Otherwise, the system will not find the path. For example, if c:\mypath is not in your path, and you add it using quotation marks: path = %path%;"c:\mypath", you must fully qualify any process in c:\mypath when starting it.

The process component obtains information about a group of properties all at once. After the Process component has obtained information about one member of any group, it will cache the values for the other properties in that group and not obtain new information about the other members of the group until you call the Refresh method. Therefore, a property value is not guaranteed to be any newer than the last call to the Refresh method. The group breakdowns are operating-system dependent.

A system process is uniquely identified on the system by its process identifier. Like many Windows resources, a process is also identified by its handle, which might not be unique on the computer. A handle is the generic term for an identifier of a resource. The operating system persists the process handle, which is accessed through the Handle property of the Process component, even when the process has exited. Thus, you can get the process's administrative information, such as the ExitCode (usually either zero for success or a nonzero error code) and the ExitTime. Handles are an extremely valuable resource, so leaking handles is more virulent than leaking memory.

NoteNote

This class contains a link demand and an inheritance demand at the class level that applies to all members. A SecurityException is thrown when either the immediate caller or the derived class does not have full-trust permission. For details about security demands, see Link Demands and Inheritance Demands.

NoteNote

The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: SharedState | Synchronization | ExternalProcessMgmt | SelfAffectingProcessMgmt. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.

The following example uses an instance of the Process class to start a process.

Imports System
Imports System.Diagnostics
Imports System.ComponentModel


Namespace MyProcessSample

    Class MyProcess

        Public Shared Sub Main()
            Dim myProcess As New Process()

            Try                ' Get the path that stores user documents.

                myProcess.StartInfo.UseShellExecute = False 
                ' You can start any process, HelloWorld is a do-nothing example.
                myProcess.StartInfo.FileName = "C:\\HelloWorld.exe"
                myProcess.StartInfo.CreateNoWindow = True
                myProcess.Start()
                ' This code assumes the process you are starting will terminate itself.  
                ' Given that is is started without a window so you cannot terminate it  
                ' on the desktop, it must terminate itself or you can do it programmatically 
                ' from this application using the Kill method. 
            Catch e As Exception
                Console.WriteLine((e.Message))
            End Try 
        End Sub 'Main
    End Class 
End Namespace

The following example uses the Process class itself and a static Start method to start a process.

Imports System
Imports System.Diagnostics
Imports System.ComponentModel

Namespace MyProcessSample
    Class MyProcess
            ' Opens the Internet Explorer application. 
            Public Sub OpenApplication(myFavoritesPath As String)
            ' Start Internet Explorer. Defaults to the home page.
            Process.Start("IExplore.exe")

            ' Display the contents of the favorites folder in the browser.
            Process.Start(myFavoritesPath)
        End Sub 'OpenApplication

        ' Opens urls and .html documents using Internet Explorer. 
        Sub OpenWithArguments()
            ' url's are not considered documents. They can only be opened 
            ' by passing them as arguments.
            Process.Start("IExplore.exe", "www.northwindtraders.com")

            ' Start a Web page using a browser associated with .html and .asp files.
            Process.Start("IExplore.exe", "C:\myPath\myFile.htm")
            Process.Start("IExplore.exe", "C:\myPath\myFile.asp")
        End Sub 'OpenWithArguments

        ' Uses the ProcessStartInfo class to start new processes, 
        ' both in a minimized mode. 
        Sub OpenWithStartInfo()
            Dim startInfo As New ProcessStartInfo("IExplore.exe")
            startInfo.WindowStyle = ProcessWindowStyle.Minimized

            Process.Start(startInfo)

            startInfo.Arguments = "www.northwindtraders.com"

            Process.Start(startInfo)
        End Sub 'OpenWithStartInfo

        Shared Sub Main()
            ' Get the path that stores favorite links. 
            Dim myFavoritesPath As String = Environment.GetFolderPath(Environment.SpecialFolder.Favorites)

            Dim myProcess As New MyProcess()

            myProcess.OpenApplication(myFavoritesPath)
            myProcess.OpenWithArguments()
            myProcess.OpenWithStartInfo()
        End Sub 'Main
    End Class 'MyProcess
End Namespace 'MyProcessSample

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

  • LinkDemand 

    for full trust for the immediate caller. This class cannot be used by partially trusted code.

  • InheritanceDemand 

    for full trust for inheritors. This class cannot be inherited by partially trusted code.

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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