Class FileStorage

Represents a storage associated with a file on disk.

Inheritance

FileStorage

Namespace: OpenCV.Net

Assembly: OpenCV.Net.dll

Syntax

public class FileStorage : SafeHandleZeroOrMinusOneIsInvalid

Constructors

| Improve this Doc View Source

FileStorage(String, MemStorage, StorageFlags, String)

Initializes a new instance of the FileStorage class and prepares the file storage for reading or writing data.

Declaration

public FileStorage(string fileName, MemStorage storage, StorageFlags flags, string encoding = null)

Parameters

Type	Name	Description
String	fileName	Name of the file associated with the storage.
MemStorage	storage	Memory storage used for temporary data and for storing dynamic structures, such as Seq or Graph. If it is null, a temporary memory storage is created and used.
StorageFlags	flags	Specifies operation flags associated with the new file storage.
String	encoding	Encoding of the file. Note that UTF-16 XML encoding is not supported currently and you should use 8-bit encoding instead.

Methods

| Improve this Doc View Source

EndWriteStruct()

Ends the writing of a structure.

Declaration

public void EndWriteStruct()

| Improve this Doc View Source

GetFileNode(FileNode, StringHashNode, Boolean)

Finds a node in a map or file storage.

Declaration

public FileNode GetFileNode(FileNode map, StringHashNode key, bool createMissing = false)

Parameters

Type	Name	Description
FileNode	map	The parent map. If it is null, the function searches a top-level node.
StringHashNode	key	Unique pointer to the node name, retrieved with GetHashedKey(String, Boolean).
Boolean	createMissing	A value indicating whether an absent node should be added to the map.

Returns

Type	Description
FileNode	The found or newly created node; null in case of failure.

| Improve this Doc View Source

GetFileNode(FileNode, String)

Finds a node in a map or file storage.

Declaration

public FileNode GetFileNode(FileNode map, string name)

Parameters

Type	Name	Description
FileNode	map	The parent map. If it is null, the function searches a top-level node.
String	name	The file node name.

Returns

Type	Description
FileNode	The found node or null in case of failure.

| Improve this Doc View Source

GetHashedKey(String, Boolean)

Returns a unique reference for a given name.

Declaration

public StringHashNode GetHashedKey(string name, bool createMissing = false)

Parameters

Type	Name	Description
String	name	Literal node name.
Boolean	createMissing	A value indicating whether an absent key should be added into the hash table.

Returns

Type	Description
StringHashNode	A unique reference for each particular file node name. This reference can later be passed to the GetFileNode(FileNode, StringHashNode, Boolean) method.

| Improve this Doc View Source

GetRootFileNode(Int32)

Retrieves one of the top-level nodes of the file storage.

Declaration

public FileNode GetRootFileNode(int streamIndex = 0)

Parameters

Type	Name	Description
Int32	streamIndex	Zero-based index of the stream. In most cases, there is only one stream in the file.

Returns

Type	Description
FileNode	One of the top-level file nodes. The top-level nodes do not have a name, they correspond to the streams that are stored one after another in the file storage. If the index is out of range, the function returns null.

| Improve this Doc View Source

Read<TElement>(FileNode)

Decodes an object and returns a reference to it.

Declaration

public TElement Read<TElement>(FileNode node)
    where TElement : CVHandle

Parameters

Type	Name	Description
FileNode	node	The root object node.

Returns

Type	Description
TElement	The reference to the decoded object.

Type Parameters

Name	Description
TElement	The type of the object.

| Improve this Doc View Source

Read<TElement>(FileNode, String)

Finds an object by name and decodes it.

Declaration

public TElement Read<TElement>(FileNode map, string name)
    where TElement : CVHandle

Parameters

Type	Name	Description
FileNode	map	The parent map. If it is null, the function searches a top-level node.
String	name	The node name.

Returns

Type	Description
TElement	The reference to the decoded object.

Type Parameters

Name	Description
TElement	The type of the object.

| Improve this Doc View Source

ReadInt(FileNode, Int32)

Retrieves an integer value from a file node.

Declaration

public int ReadInt(FileNode node, int defaultValue = 0)

Parameters

Type	Name	Description
FileNode	node	The file node.
Int32	defaultValue	The value that is returned if `node` is null.

Returns

Type	Description
Int32	An integer that is represented by the file node.

| Improve this Doc View Source

ReadInt(FileNode, String, Int32)

Finds a file node and returns its integer value.

Declaration

public int ReadInt(FileNode map, string name, int defaultValue = 0)

Parameters

Type	Name	Description
FileNode	map	The parent map. If it is null, the function searches a top-level node.
String	name	The node name.
Int32	defaultValue	The value that is returned if the file node is not found.

Returns

Type	Description
Int32	An integer that is represented by the file node.

| Improve this Doc View Source

ReadRawData<TElement>(FileNode, TElement[], String)

Reads multiple numbers.

Declaration

public void ReadRawData<TElement>(FileNode src, TElement[] dst, string format)
    where TElement : struct

Parameters

Type	Name	Description
FileNode	src	The file node (a sequence) to read numbers from.
TElement[]	dst	The destination array.
String	format	Specification of each array element.

Type Parameters

Name	Description
TElement	The type of the numbers to read.

| Improve this Doc View Source

ReadReal(FileNode, Double)

Retrieves a floating-point value from a file node.

Declaration

public double ReadReal(FileNode node, double defaultValue = null)

Parameters

Type	Name	Description
FileNode	node	The file node.
Double	defaultValue	The value that is returned if `node` is null.

Returns

Type	Description
Double	A floating-point value that is represented by the file node.

| Improve this Doc View Source

ReadReal(FileNode, String, Double)

Finds a file node and returns its floating-point value.

Declaration

public double ReadReal(FileNode map, string name, double defaultValue = null)

Parameters

Type	Name	Description
FileNode	map	The parent map. If it is null, the function searches a top-level node.
String	name	The node name.
Double	defaultValue	The value that is returned if the file node is not found.

Returns

Type	Description
Double	A floating-point value that is represented by the file node.

| Improve this Doc View Source

ReadString(FileNode, String)

Retrieves a text string from a file node.

Declaration

public string ReadString(FileNode node, string defaultValue = null)

Parameters

Type	Name	Description
FileNode	node	The file node.
String	defaultValue	The value that is returned if `node` is null.

Returns

Type	Description
String	A text string that is represented by the file node.

| Improve this Doc View Source

ReadString(FileNode, String, String)

Finds a file node and returns its text string value.

Declaration

public string ReadString(FileNode map, string name, string defaultValue = null)

Parameters

Type	Name	Description
FileNode	map	The parent map. If it is null, the function searches a top-level node.
String	name	The node name.
String	defaultValue	The value that is returned if the file node is not found.

Returns

Type	Description
String	A text string that is represented by the file node.

| Improve this Doc View Source

ReleaseHandle()

Executes the code required to free the native FileStorage handle.

Declaration

protected override bool ReleaseHandle()

Returns

Type	Description
Boolean	true if the handle is released successfully; otherwise, in the event of a catastrophic failure, false.

| Improve this Doc View Source

StartNextStream()

Starts the next stream in file storage. Both YAML and XML support multiple streams. This is useful for concatenating files or for resuming the writing process.

Declaration

public void StartNextStream()

| Improve this Doc View Source

StartWriteStruct(String, StructStorageFlags, String, AttrList)

Starts writing a new structure.

Declaration

public void StartWriteStruct(string name, StructStorageFlags structFlags, string typeName = null, AttrList attributes = default(AttrList))

Parameters

Type	Name	Description
String	name	Name of the written structure. The structure can be accessed by this name when the storage is read.
StructStorageFlags	structFlags	Operation flags associated with the written structure.
String	typeName	Optional parameter, the object type name. In case of XML it is written as a type_id attribute of the structure opening tag. In the case of YAML it is written after a colon following the structure name.
AttrList	attributes	Not used in the current implementation.

| Improve this Doc View Source

Write(String, CVHandle, AttrList)

Writes an object to file storage.

Declaration

public void Write(string name, CVHandle handle, AttrList attributes = default(AttrList))

Parameters

Type	Name	Description
String	name	Name of the written object. Should be null if and only if the parent structure is a sequence.
CVHandle	handle	Handle to the written object.
AttrList	attributes	The attributes of the object. They are specific for each particular type.

| Improve this Doc View Source

WriteComment(String, Boolean)

Writes a comment.

Declaration

public void WriteComment(string comment, bool eolComment)

Parameters

Type	Name	Description
String	comment	The written comment, single-line or multi-line.
Boolean	eolComment	If true, the method tries to put the comment at the end of current line; otherwise, if the comment is multi-line, or if it does not fit at the end of the current line, the comment starts a new line.

| Improve this Doc View Source

WriteFileNode(String, FileNode, Boolean)

Writes a file node from another file storage.

Declaration

public void WriteFileNode(string newNodeName, FileNode node, bool embed)

Parameters

Type	Name	Description
String	newNodeName	New name of the file node in the destination file storage. To keep the existing name, use the Name property.
FileNode	node	The written node.
Boolean	embed	If the written node is a collection and this parameter is true, no extra level of hierarchy is created. Instead, all the elements of node are written into the currently written structure. Of course, map elements can only be embedded into another map, and sequence elements can only be embedded into another sequence.

| Improve this Doc View Source

WriteInt(String, Int32)

Writes an integer value.

Declaration

public void WriteInt(string name, int value)

Parameters

Type	Name	Description
String	name	Name of the written value. Should be null if and only if the parent structure is a sequence.
Int32	value	The written value.

| Improve this Doc View Source

WriteRawData<TElement>(TElement[], String)

Writes multiple numbers.

Declaration

public void WriteRawData<TElement>(TElement[] source, string format)
    where TElement : struct

Parameters

Type	Name	Description
TElement[]	source	The source array.
String	format	Specification of each array element.

Type Parameters

Name	Description
TElement	The type of the numbers to write.

| Improve this Doc View Source

WriteReal(String, Double)

Writes a floating-point value.

Declaration

public void WriteReal(string name, double value)

Parameters

Type	Name	Description
String	name	Name of the written value. Should be null if and only if the parent structure is a sequence.
Double	value	The written value.

| Improve this Doc View Source

WriteString(String, String, Boolean)

Writes a text string.

Declaration

public void WriteString(string name, string value, bool quote = false)

Parameters

Type	Name	Description
String	name	Name of the written string. Should be null if and only if the parent structure is a sequence.
String	value	The written string.
Boolean	quote	If true, the written string is put in quotes, regardless of whether they are required. Otherwise, if the flag is zero, quotes are used only when they are required (e.g. when the string starts with a digit or contains spaces).