NSData.FromFile Method
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Overloads
| FromFile(String) |
Creates an NSData by loading the contents of the specified file into memory. |
| FromFile(String, NSDataReadingOptions, NSError) |
Creates an NSData by loading the contents of the specified file into memory. |
FromFile(String)
Creates an NSData by loading the contents of the specified file into memory.
[Foundation.Export("dataWithContentsOfFile:")]
public static Foundation.NSData FromFile (string path);static member FromFile : string -> Foundation.NSDataParameters
- path
- String
Path to the filename to wrap as an NSData.
Returns
Newly created NSData object exposing the contents of the file, or null on error.
- Attributes
Remarks
This version of FromFile loads the contents of the file into memory on startup, use the M:Foundation.NSData.FromFile(string,Foundation.NSDataReadingOptions,Foundation.Error) to use mmap.
Applies to
FromFile(String, NSDataReadingOptions, NSError)
Creates an NSData by loading the contents of the specified file into memory.
[Foundation.Export("dataWithContentsOfFile:options:error:")]
public static Foundation.NSData FromFile (string path, Foundation.NSDataReadingOptions mask, out Foundation.NSError error);static member FromFile : string * Foundation.NSDataReadingOptions * -> Foundation.NSDataParameters
- path
- String
Path to the filename to wrap as an NSData.
- mask
- NSDataReadingOptions
Options can be used to control the file loading, can be used to force the file to be mapped into the VM, instead of loaded by reading the contents.
- error
- NSError
Returns the error on failure.
Returns
Newly created NSData object exposing the contents of the file, or null on error.
- Attributes
Remarks
By default NSData will loads the contents of the file in memory by allocating a block of memory and then reading the contents of the file into it.
The Mapped and MappedAlways parameter instruct NSData to use the kernel's interface to map the file into the process address space. This has a few advantages: instead of allocating read/write memory for the process, that becomes real memory usage, the mapped versions map the file into memory which means that the data is loaded on demand instead of being loaded upfront. This also allows the kernel to discard the data loaded from memory when the system is running low on memory.