FileSystem.Lock Method (Microsoft.VisualBasic)

Parameters

Examples

This example illustrates the use of the Lock and Unlock functions. This example assumes that People.txt is a file that contains records of the structure Person .
Structure Person
    Dim Name As String
    Dim ID As Integer
End Structure
Sub PutInLockedFile(ByVal onePerson As Person)
    FileOpen(1, "c:\people.txt", OpenMode.Binary)
    Lock(1)
    FilePut(1, onePerson)
    Unlock(1)
    FileClose(1)
End Sub
    	Remarks
    	The Lock and Unlock functions are used in environments where several processes might need access to the same file.
Lock and Unlock functions are always used in pairs. The arguments to Lock and Unlock must be identical.
If Record, or FromRecord and ToRecord are not supplied, the lock will be for the whole file. If Record alone is specified the single record will be locked/unlocked.
If the file has been opened for sequential input or output, Lock and Unlock affect the whole file, regardless of the range specified by FromRecord andToRecord.
	public:
 static void Lock(int FileNumber, long Record);
	public static void Lock (int FileNumber, long Record);
	[System.Runtime.Versioning.UnsupportedOSPlatform("ios")]
[System.Runtime.Versioning.UnsupportedOSPlatform("macos")]
[System.Runtime.Versioning.UnsupportedOSPlatform("tvos")]
public static void Lock (int FileNumber, long Record);
	static member Lock : int * int64 -> unit
	[<System.Runtime.Versioning.UnsupportedOSPlatform("ios")>]
[<System.Runtime.Versioning.UnsupportedOSPlatform("macos")>]
[<System.Runtime.Versioning.UnsupportedOSPlatform("tvos")>]
static member Lock : int * int64 -> unit
	Public Sub Lock (FileNumber As Integer, Record As Long)
	Parameters
  Examples
    	This example illustrates the use of the Lock and Unlock functions. This example assumes that People.txt is a file that contains records of the structure Person.
Structure Person
    Dim Name As String
    Dim ID As Integer
End Structure
Sub PutInLockedFile(ByVal onePerson As Person)
    FileOpen(1, "c:\people.txt", OpenMode.Binary)
    Lock(1)
    FilePut(1, onePerson)
    Unlock(1)
    FileClose(1)
End Sub
    	Remarks
    	The Lock and Unlock functions are used in environments where several processes might need access to the same file.
Lock and Unlock functions are always used in pairs. The arguments to Lock and Unlock must be identical.
If Record, or FromRecord and ToRecord are not supplied, the lock will be for the whole file. If Record alone is specified the single record will be locked/unlocked.
If the file has been opened for sequential input or output, Lock and Unlock affect the whole file, regardless of the range specified by FromRecord andToRecord.
	public:
 static void Lock(int FileNumber, long FromRecord, long ToRecord);
	public static void Lock (int FileNumber, long FromRecord, long ToRecord);
	[System.Runtime.Versioning.UnsupportedOSPlatform("ios")]
[System.Runtime.Versioning.UnsupportedOSPlatform("macos")]
[System.Runtime.Versioning.UnsupportedOSPlatform("tvos")]
public static void Lock (int FileNumber, long FromRecord, long ToRecord);
	static member Lock : int * int64 * int64 -> unit
	[<System.Runtime.Versioning.UnsupportedOSPlatform("ios")>]
[<System.Runtime.Versioning.UnsupportedOSPlatform("macos")>]
[<System.Runtime.Versioning.UnsupportedOSPlatform("tvos")>]
static member Lock : int * int64 * int64 -> unit
	Public Sub Lock (FileNumber As Integer, FromRecord As Long, ToRecord As Long)
	Parameters
  Examples
    	This example illustrates the use of the Lock and Unlock functions. This example assumes that People.txt is a file that contains records of the structure Person.
Structure Person
    Dim Name As String
    Dim ID As Integer
End Structure
Sub PutInLockedFile(ByVal onePerson As Person)
    FileOpen(1, "c:\people.txt", OpenMode.Binary)
    Lock(1)
    FilePut(1, onePerson)
    Unlock(1)
    FileClose(1)
End Sub
    	Remarks
    	The Lock and Unlock functions are used in environments where several processes might need access to the same file.
Lock and Unlock functions are always used in pairs. The arguments to Lock and Unlock must be identical.
If Record, or FromRecord and ToRecord are not supplied, the lock will be for the whole file. If Record alone is specified the single record will be locked/unlocked.
If the file has been opened for sequential input or output, Lock and Unlock affect the whole file, regardless of the range specified by FromRecord andToRecord.
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