Class PageLabel
<p>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.
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);
}Implements
Inherited Members
Namespace: pdftron.PDF
Assembly: PDFNet.dll
Syntax
public class PageLabel : IDisposableConstructors
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()
Releases all resources used by the PageLabel
Declaration
public override sealed void Dispose()Dispose(bool)
Declaration
[HandleProcessCorruptedStateExceptions]
protected virtual void Dispose(bool A_0)Parameters
| Type | Name | Description |
|---|---|---|
| bool | A_0 |
~PageLabel()
Allows a PageLabel to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.
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 |