MemoryMappedFile.CreateViewAccessor Method
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Creates a MemoryMappedViewAccessor that maps to a view of the memory-mapped file.
| CreateViewAccessor() |
Creates a MemoryMappedViewAccessor that maps to a view of the memory-mapped file. |
| CreateViewAccessor(Int64, Int64) |
Creates a MemoryMappedViewAccessor that maps to a view of the memory-mapped file, and that has the specified offset and size. |
| CreateViewAccessor(Int64, Int64, MemoryMappedFileAccess) |
Creates a MemoryMappedViewAccessor that maps to a view of the memory-mapped file, and that has the specified offset, size, and access restrictions. |
- Source:
- MemoryMappedFile.cs
- Source:
- MemoryMappedFile.cs
- Source:
- MemoryMappedFile.cs
Creates a MemoryMappedViewAccessor that maps to a view of the memory-mapped file.
public:
System::IO::MemoryMappedFiles::MemoryMappedViewAccessor ^ CreateViewAccessor();public System.IO.MemoryMappedFiles.MemoryMappedViewAccessor CreateViewAccessor();member this.CreateViewAccessor : unit -> System.IO.MemoryMappedFiles.MemoryMappedViewAccessorPublic Function CreateViewAccessor () As MemoryMappedViewAccessorReturns
A randomly accessible block of memory.
Exceptions
Access to the memory-mapped file is unauthorized.
Remarks
You can use the view returned by this method for random access to a memory-mapped file.
See also
Applies to
.NET 10 and other versions
| Product | Versions |
|---|---|
| .NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10 |
| .NET Framework | 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
| .NET Standard | 2.0, 2.1 |
- Source:
- MemoryMappedFile.cs
- Source:
- MemoryMappedFile.cs
- Source:
- MemoryMappedFile.cs
Creates a MemoryMappedViewAccessor that maps to a view of the memory-mapped file, and that has the specified offset and size.
public:
System::IO::MemoryMappedFiles::MemoryMappedViewAccessor ^ CreateViewAccessor(long offset, long size);public System.IO.MemoryMappedFiles.MemoryMappedViewAccessor CreateViewAccessor(long offset, long size);member this.CreateViewAccessor : int64 * int64 -> System.IO.MemoryMappedFiles.MemoryMappedViewAccessorPublic Function CreateViewAccessor (offset As Long, size As Long) As MemoryMappedViewAccessorParameters
- offset
- Int64
The byte at which to start the view.
- size
- Int64
The size of the view. Specify 0 (zero) to create a view that starts at offset and ends approximately at the end of the memory-mapped file.
Returns
A randomly accessible block of memory.
Exceptions
offset or size is a negative value.
-or-
size is greater than the logical address space.
Access to the memory-mapped file is unauthorized.
An I/O error occurred.
Examples
The following example creates a view of a memory-mapped file and edits it. This code example is part of a larger example provided for the MemoryMappedFile class.
// Create a random access view, from the 256th megabyte (the offset)
// to the 768th megabyte (the offset plus length).
using (var accessor = mmf.CreateViewAccessor(offset, length))
{
int colorSize = Marshal.SizeOf(typeof(MyColor));
MyColor color;
// Make changes to the view.
for (long i = 0; i < length; i += colorSize)
{
accessor.Read(i, out color);
color.Brighten(10);
accessor.Write(i, ref color);
}
}
' Create a random access view, from the 256th megabyte (the offset)
' to the 768th megabyte (the offset plus length).
Using accessor = mmf.CreateViewAccessor(offset, length)
Dim colorSize As Integer = Marshal.SizeOf(GetType(MyColor))
Dim color As MyColor
Dim i As Long = 0
' Make changes to the view.
Do While (i < length)
accessor.Read(i, color)
color.Brighten(10)
accessor.Write(i, color)
i += colorSize
Loop
End Using
Remarks
You can use the view returned by this method for random access to a memory-mapped file.
To create a complete view of the memory-mapped file, specify 0 (zero) for the size parameter. If you do this, the size of the view might be larger than the size of the source file on disk. This is because views are provided in units of system pages, and the size of the view is rounded up to the next system page size.
See also
Applies to
.NET 10 and other versions
| Product | Versions |
|---|---|
| .NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10 |
| .NET Framework | 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
| .NET Standard | 2.0, 2.1 |
- Source:
- MemoryMappedFile.cs
- Source:
- MemoryMappedFile.cs
- Source:
- MemoryMappedFile.cs
Creates a MemoryMappedViewAccessor that maps to a view of the memory-mapped file, and that has the specified offset, size, and access restrictions.
public:
System::IO::MemoryMappedFiles::MemoryMappedViewAccessor ^ CreateViewAccessor(long offset, long size, System::IO::MemoryMappedFiles::MemoryMappedFileAccess access);public System.IO.MemoryMappedFiles.MemoryMappedViewAccessor CreateViewAccessor(long offset, long size, System.IO.MemoryMappedFiles.MemoryMappedFileAccess access);[System.Security.SecurityCritical]
public System.IO.MemoryMappedFiles.MemoryMappedViewAccessor CreateViewAccessor(long offset, long size, System.IO.MemoryMappedFiles.MemoryMappedFileAccess access);member this.CreateViewAccessor : int64 * int64 * System.IO.MemoryMappedFiles.MemoryMappedFileAccess -> System.IO.MemoryMappedFiles.MemoryMappedViewAccessor[<System.Security.SecurityCritical>]
member this.CreateViewAccessor : int64 * int64 * System.IO.MemoryMappedFiles.MemoryMappedFileAccess -> System.IO.MemoryMappedFiles.MemoryMappedViewAccessorPublic Function CreateViewAccessor (offset As Long, size As Long, access As MemoryMappedFileAccess) As MemoryMappedViewAccessorParameters
- offset
- Int64
The byte at which to start the view.
- size
- Int64
The size of the view. Specify 0 (zero) to create a view that starts at offset and ends approximately at the end of the memory-mapped file.
- access
- MemoryMappedFileAccess
One of the enumeration values that specifies the type of access allowed to the memory-mapped file. The default is ReadWrite.
Returns
A randomly accessible block of memory.
- Attributes
Exceptions
offset or size is a negative value.
-or-
size is greater than the logical address space.
access is invalid for the memory-mapped file.
An I/O error occurred.
Remarks
You can use the view returned by this method for random access to a memory-mapped file.
To create a complete view of the memory-mapped file, specify 0 (zero) for the size parameter. If you do this, the size of the view might be larger than the size of the source file on disk. This is because views are provided in units of system pages, and the size of the view is rounded up to the next system page size.
See also
Applies to
.NET 10 and other versions
| Product | Versions |
|---|---|
| .NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10 |
| .NET Framework | 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
| .NET Standard | 2.0, 2.1 |
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