Class QrSegment

Namespace

Net.Codecrete.QrCodeGenerator

Assembly

QrCodeGenerator.dll

Represents a segment of character/binary/control data in a QR code symbol.

public class QrSegment

Inheritance

object

QrSegment

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Remarks

The easiest way to deal with QR code segments is to call EncodeText(string, Ecc) or EncodeBinary(byte[], Ecc), and not to use instances of this class directly. The mid-level way is to take the payload data and call a static factory function such as MakeNumeric(string). The low-level way is to custom-make the bit array and call the QrSegment(Mode, int, BitArray) constructor with appropriate values.

This segment class imposes no length restrictions, but QR codes have restrictions. Even in the most favorable conditions, a QR code can only hold 7089 characters of data. Any segment longer than this is meaningless for the purpose of generating QR codes.

This class can represent kanji mode segments, but provides no help in encoding them - see QrSegmentAdvanced for full kanji support.

Instances of this class are immutable.

Constructors

QrSegment(Mode, int, BitArray)

Initializes a QR code segment with the specified attributes and data.

The character count numChars must agree with the mode and the bit array length, but the constraint isn't checked. The specified bit array is cloned.

public QrSegment(QrSegment.Mode mode, int numChars, BitArray data)

Parameters

mode QrSegment.Mode

The segment mode used to encode this segment.

numChars int

The data length in characters or bytes (depending on the segment mode).

data BitArray

The data bits.

Exceptions

ArgumentNullException

mode or data is null.

ArgumentOutOfRangeException

numChars is negative.

Properties

EncodingMode

The encoding mode of this segment.

public QrSegment.Mode EncodingMode { get; }

Property Value

QrSegment.Mode

Encoding mode.

NumChars

The length of this segment's unencoded data.

Measured in characters for numeric/alphanumeric/kanji mode, bytes for byte mode, and 0 for ECI mode.

Different from the data's bit length.

public int NumChars { get; }

Property Value

int

Length of the segment's unencoded data.

Methods

GetData()

Returns a copy of this segment's data bits.

public BitArray GetData()

Returns

BitArray

A copy of the data bits.

GetJoinedText(List<QrSegment>)

Returns the joined text represented by the provided segments.

public static string GetJoinedText(List<QrSegment> segments)

Parameters

segments List<QrSegment>

List of segments

Returns

string

GetJoinedText(List<List<QrSegment>>)

Returns the joined text represented by the provided segments.

public static string GetJoinedText(List<List<QrSegment>> segments)

Parameters

segments List<List<QrSegment>>

List of list of segments

Returns

string

GetText()

Returns the text represented by this segment.

This method will fail if the segment contains binary data that cannot be converted to text.

public string GetText()

Returns

string

The text.

IsAlphanumeric(string)

Tests whether the specified string can be encoded as a segment in alphanumeric mode.

A string is encodable iff each character is in the range "0" to "9", "A" to "Z" (uppercase only), space, dollar, percent, asterisk, plus, hyphen, period, slash, colon.

public static bool IsAlphanumeric(string text)

Parameters

text string

the string to test for encodability (not null)

Returns

bool

true iff each character is in the alphanumeric mode character set.

Exceptions

NullReferenceException

if the string is null

See Also

MakeAlphanumeric(string)

IsNumeric(string)

Tests whether the specified string can be encoded as a segment in numeric mode.

A string is encodable iff each character is in the range "0" to "9".

public static bool IsNumeric(string text)

Parameters

text string

the string to test for encodability (not null)

Returns

bool

true iff each character is in the range "0" to "9".

Exceptions

NullReferenceException

if the string is null

See Also

MakeNumeric(string)

MakeAlphanumeric(string)

Creates a segment representing the specified text string. The segment is encoded in alphanumeric mode.

Allowed characters are: 0 to 9, A to Z (uppercase only), space, dollar, percent, asterisk, plus, hyphen, period, slash, colon.

public static QrSegment MakeAlphanumeric(string text)

Parameters

text string

The text to encode, consisting of allowed characters only.

Returns

QrSegment

The created segment containing the text.

Exceptions

ArgumentNullException

text is null.

ArgumentOutOfRangeException

text contains non-encodable characters.

MakeBytes(ArraySegment<byte>)

Creates a segment representing the specified binary data encoded in byte mode. All input byte arrays are acceptable.

Any text string can be converted to UTF-8 bytes (using Encoding.UTF8.GetBytes(str)) and encoded as a byte mode segment.

public static QrSegment MakeBytes(ArraySegment<byte> data)

Parameters

data ArraySegment<byte>

The binary data to encode.

Returns

QrSegment

The created segment containing the specified data.

Exceptions

ArgumentNullException

data is null.

MakeBytes(byte[])

Creates a segment representing the specified binary data encoded in byte mode. All input byte arrays are acceptable.

Any text string can be converted to UTF-8 bytes (using Encoding.UTF8.GetBytes(str)) and encoded as a byte mode segment.

public static QrSegment MakeBytes(byte[] data)

Parameters

data byte[]

The binary data to encode.

Returns

QrSegment

The created segment containing the specified data.

Exceptions

ArgumentNullException

data is null.

MakeEci(int)

Creates a segment representing an Extended Channel Interpretation (ECI) designator with the specified assignment value.

public static QrSegment MakeEci(int assignVal)

Parameters

assignVal int

The ECI assignment number (see the AIM ECI specification).

Returns

QrSegment

The created segment containing the data.

Exceptions

ArgumentOutOfRangeException

assignValis outside the range [0, 10⁶).

MakeNumeric(string)

Creates a segment representing the specified string of decimal digits. The segment is encoded in numeric mode.

public static QrSegment MakeNumeric(string digits)

Parameters

digits string

The text to encode, consisting of digits from 0 to 9 only.

Returns

QrSegment

The created segment containing the text.

Exceptions

ArgumentNullException

digits is null.

ArgumentOutOfRangeException

digits contains non-digit characters

MakeSegments(string)

Creates a list of zero or more segments representing the specified text string.

The text may contain the full range of Unicode characters.

The result may consist of multiple segments with various encoding modes in order to minimize the length of the bit stream.

public static List<QrSegment> MakeSegments(string text)

Parameters

text string

The text to be encoded.

Returns

List<QrSegment>

The created mutable list of segments representing the specified text.

Remarks

The current implementation does not create multiple segments.

Exceptions

ArgumentNullException

text is null.