FileSystemWatcher.Filter Property

 
System_CAPS_noteNote

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Gets or sets the filter string used to determine what files are monitored in a directory.

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

[<IODescriptionAttribute("FSW_Filter")>]
[<TypeConverterAttribute("System.Diagnostics.Design.StringValueConverter, System.Design, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")>]
[<SettingsBindableAttribute(true)>]
member Filter : string with get, set

Property Value

Type: System.String

The filter string. The default is "*.*" (Watches all files.)

To watch changes in all files, set the Filter property to an empty string (""). To watch a specific file, set the Filter property to the file name. For example, to watch for changes in the file MyDoc.txt, set the Filter property to "MyDoc.txt". You can also watch for changes in a certain type of file. For example, to watch for changes in any text files, set the Filter property to "*.txt". Use of multiple filters such as "*.txt|*.doc" is not supported.

The Filter property can be changed after the FileSystemWatcher object has started receiving events.

For more information about filtering out unwanted notifications, see the NotifyFilter, IncludeSubdirectories, and InternalBufferSize properties.

Filter accepts wildcards for matching files, as shown in the following examples.

Filter string

Watches the following files

*.*

All files (default). An empty string ("") also watches all files.

*.txt

All files with a "txt" extension.

*recipe.doc

All files ending in "recipe" with a "doc" extension.

win*.xml

All files beginning with "win" with an "xml" extension.

Sales*200?.xls

Matches the following:

Sales July 2001.xlsSales Aug 2002.xlsSales March 2004.xls

but does not match:

Sales Nov 1999.xls

MyReport.Doc

Watches only MyReport.doc

The following example creates a FileSystemWatcher to watch the directory specified at run time. The component is set to watch for changes in LastWrite and LastAccess time, the creation, deletion, or renaming of text files in the directory. If a file is changed, created, or deleted, the path to the file prints to the console. When a file is renamed, the old and new paths print to the console.

Use the System.Diagnostics and System.IO namespaces for this example.

No code example is currently available or this language may not be supported.

.NET Framework
Available since 1.1
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