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# Class PageLabel

PDF page labels can be used to describe a page. This is used to allow for non-sequential page numbering or the addition of arbitrary labels for a page (such as the inclusion of Roman numerals at the beginning of a book). PDFNet PageLabel object can be used to specify the numbering style to use (for example, upper- or lower-case Roman, decimal, and so forth), the starting number for the first page, and an arbitrary prefix to be pre-appended to each number (for example, "A-" to generate "A-1", "A-2", "A-3", and so forth.)

`PageLabel` corresponds to the PDF Page Label object (Section 8.3.1, 'Page Labels' in the PDF Reference Manual.

Each page in a PDF document is identified by an integer page index that expresses the page's relative position within the document. In addition, a document may optionally define page labels to identify each page visually on the screen or in print. Page labels and page indices need not coincide: the indices are fixed, running consecutively through the document starting from 1 for the first page, but the labels can be specified in any way that is appropriate for the particular document. For example, if the document begins with 12 pages of front matter numbered in roman numerals and the remainder of the document is numbered in Arabic, the first page would have a page index of 1 and a page label of i, the twelfth page would have index 12 and label xii, and the thirteenth page would have index 13 and label 1.

For purposes of page labeling, a document can be divided into labeling ranges, each of which is a series of consecutive pages using the same numbering system. Pages within a range are numbered sequentially in ascending order. A page's label consists of a numeric portion based on its position within its labeling range, optionally preceded by a label prefix denoting the range itself. For example, the pages in an appendix might be labeled with decimal numeric portions prefixed with the string "A-" and the resulting page labels would be "A-1", "A-2",

There is no default numbering style; if no 'S' (Style) entry is present, page labels consist solely of a label prefix with no numeric portion. For example, if the 'P' entry (Prefix) specifies the label prefix "Appendix", each page is simply labeled "Appendix" with no page number. If the 'P' entry is also missing or empty, the page label is an empty string.

Sample code (See PableLabelsTest sample project for examples):

Create a page labeling scheme that starts with the first page in the document (page 1) and is using uppercase roman numbering style.

    doc.SetPageLabel(1, PageLabel::Create(doc, PageLabel::e_roman_uppercase, "My Prefix ", 1));

Create a page labeling scheme that starts with the fourth page in the document and is using decimal arabic numbering style. Also the numeric portion of the first label should start with number 4 (otherwise the first label would be "My Prefix 1").

    PageLabel L2 = PageLabel::Create(doc, PageLabel::e_decimal, "My Prefix ", 4);
    doc.SetPageLabel(4, L2);

Create a page labeling scheme that starts with the seventh page in the document and is using alphabetic numbering style. The numeric portion of the first label should start with number 1.

    PageLabel L3 = PageLabel::Create(doc, PageLabel::e_alphabetic_uppercase, "My Prefix ", 1);
    doc.SetPageLabel(7, L3);

Read page labels from an existing PDF document.

    PageLabel label = new PageLabel();
    for (int i=1; i<=doc.GetPageCount(); ++i) {
    label = doc.GetPageLabel(i);
    if (label.IsValid()) {
    string title = label.GetLabelTitle(i);
    }

##### Inheritance

object
PageLabel

##### Implements

IDisposable

##### Inherited Members

object.Equals(object)
object.Equals(object, object)
object.GetHashCode()
object.GetType()
object.MemberwiseClone()
object.ReferenceEquals(object, object)
object.ToString()

###### Namespace: pdftron.PDF

###### Assembly: PDFTronDotNet.dll

##### Syntax

    public class PageLabel : IDisposable

### Constructors

#### PageLabel()

##### Declaration

    public PageLabel()

#### PageLabel(Obj)

Instantiates a new page label.

##### Declaration

    public PageLabel(Obj obj)

##### Parameters

Type | Name | Description
--- | --- | ---
Obj | obj | the l

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

### Methods

#### Create(SDFDoc, Style, string, int)

Creates a new PageLabel.

##### Declaration

    public static PageLabel Create(SDFDoc doc, PageLabel.Style style, string prefix, int start_at)

##### Parameters

Type | Name | Description
--- | --- | ---
SDFDoc | doc | A document to which the page label is added.
PageLabel.Style | style | The numbering style for the label.
string | prefix | page label prefix
int | start_at | start at position

##### Returns

Type | Description
--- | ---
PageLabel | newly created PageLabel object.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### Dispose()

Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.

##### Declaration

    public void Dispose()

#### Dispose(bool)

##### Declaration

    protected virtual void Dispose(bool disposing)

##### Parameters

Type | Name | Description
--- | --- | ---
bool | disposing |

#### ~PageLabel()

Releases all resources used by the PageLabel

##### Declaration

    protected ~PageLabel()

#### GetFirstPageNum()

Gets the first page num.

##### Declaration

    public int GetFirstPageNum()

##### Returns

Type | Description
--- | ---
int | the first page in the range associated with this label or -1 if the label is not associated with any page.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetLabelTitle(int)

Gets full tittle of the page label

##### Declaration

    public string GetLabelTitle(int page_num)

##### Parameters

Type | Name | Description
--- | --- | ---
int | page_num | page number

##### Returns

Type | Description
--- | ---
string | the full label title that is in effect for the given page. If there is no label object in effect, this method returns an empty string.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetLastPageNum()

Gets the last page num.

##### Declaration

    public int GetLastPageNum()

##### Returns

Type | Description
--- | ---
int | the last page in the range associated with this label or -1 if the label is not associated with any page.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetPrefix()

Gets the prefix.

##### Declaration

    public string GetPrefix()

##### Returns

Type | Description
--- | ---
string | the string used to prefix the numeric portion of the page label

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetSDFObj()

Gets the sDF obj.

##### Declaration

    public Obj GetSDFObj()

##### Returns

Type | Description
--- | ---
Obj | The pointer to the underlying SDF/Cos object.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetStart()

Gets the start.

##### Declaration

    public int GetStart()

##### Returns

Type | Description
--- | ---
int | the value to use when generating the numeric portion of the first label in this range; must be greater than or equal to 1.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### GetStyle()

Gets the style.

##### Declaration

    public PageLabel.Style GetStyle()

##### Returns

Type | Description
--- | ---
PageLabel.Style | page numbering style.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### IsValid()

Checks if is valid.

##### Declaration

    public bool IsValid()

##### Returns

Type | Description
--- | ---
bool | whether this is a valid (non-null) PageLabel. If the function returns false the underlying SDF/Cos object is null or is not valid and the PageLabel object should be treated as null as well.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### SetPrefix(string)

Sets the prefix.

##### Declaration

    public void SetPrefix(string prefix)

##### Parameters

Type | Name | Description
--- | --- | ---
string | prefix | the string used to prefix the numeric portion of the page label.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### SetStart(int)

Sets the start.

##### Declaration

    public void SetStart(int start_at)

##### Parameters

Type | Name | Description
--- | --- | ---
int | start_at | the value to use when generating the numeric portion of the first label in this range; must be greater than or equal to 1.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### SetStyle(Style)

Sets the numbering style for the label.

##### Declaration

    public void SetStyle(PageLabel.Style style)

##### Parameters

Type | Name | Description
--- | --- | ---
PageLabel.Style | style | the numbering style for the label.

##### Remarks

You may use label style to customize the page numbering schemes used throughout a document. There are three numbering formats:

There is no default numbering style; if no 'S' (Style) entry is present, page labels consist solely of a label prefix with no numeric portion.

##### Exceptions

Type | Condition
--- | ---
PDFNetException | PDFNetException the PDFNet exception

#### op_Assign(PageLabel)

##### Declaration

    public PageLabel op_Assign(PageLabel r)

##### Parameters

Type | Name | Description
--- | --- | ---
PageLabel | r |

##### Returns

Type | Description
--- | ---
PageLabel |

#### op_Compare(PageLabel)

##### Declaration

    public bool op_Compare(PageLabel r)

##### Parameters

Type | Name | Description
--- | --- | ---
PageLabel | r |

##### Returns

Type | Description
--- | ---
bool |

### Implements

IDisposable