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# Class ContentReplacer

ContentReplacer is a utility class for replacing content (text and images) in existing PDF (template) documents.

Users can replace content in a PDF page using the following operations:

- Replace an image that exists in a target rectangle with a replacement image.
- Replace text that exists in a target rectangle with replacement text.
- Replace all instances of a specially marked string with replacement string.

The following code replaces an image in a target region. It also replaces the text "[NAME]" and "[JOB_TITLE]" with "John Smith" and "Software Developer" respectively. Notice the square braces ('[' and ']') on the target strings in the original PDFDoc. These square braces are not included in the actual function calls below, as they're implicitly added.

    PDFDoc doc("../../TestFiles/BusinessCardTemplate.pdf");
    doc.InitSecurityHandler();
    ContentReplacer replacer;
    Page pg = doc.GetPage(1);
    Image img = Image.Create(doc, "../../TestFiles/peppers.jpg");
    replacer.AddImage(page.GetMediaBox(), img.GetSDFObj());
    replacer.AddString("NAME", "John Smith");
    replacer.AddString("JOB_TITLE", "Software Developer");
    replacer.Process(page);

##### Inheritance

object
ContentReplacer

##### 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 ContentReplacer : IDisposable

### Constructors

#### ContentReplacer()

Create a new ContentReplacer object, to which replacement rules will be added. The same object can be used to 'Process' multiple pages.

##### Declaration

    public ContentReplacer()

### Methods

#### AddImage(Rect, Obj)

Replace the image that best fits 'target_region' with 'replacement_image'.

##### Declaration

    public void AddImage(Rect target_region, Obj replacement_image)

##### Parameters

Type | Name | Description
--- | --- | ---
Rect | target_region | The rectangle defining the area in which an image that best fits the rectangle will be replaced by 'replacement_image'.
Obj | replacement_image | The 'SDF.Obj' of a 'PDF.Image' object.

##### Remarks

The best fit is the image that closest matches 'target_region'. For example if there are two images on the page, one taking up the entire page, and the other smaller, and the smaller one has similar dimensions and position of 'target_region', then the smaller image would be replaced, not the larger. Furthermore, if 'target_region' encloses multiple images, then only the image with the largest area will be replaced.

#### AddString(string, string)

Any text of the form "[template_text]" will be replaced by "replacement_text".

##### Declaration

    public void AddString(string template_text, string replacement_text)

##### Parameters

Type | Name | Description
--- | --- | ---
string | template_text | The text to remove.
string | replacement_text | The new text that will appear in place of 'template_text'.

##### Remarks

Only text wrapped in '[' and ']' will be checked, and if it matches 'template_text', then 'template_text' and the surrounding square braces will be replaced by 'replacement_text'. For example AddString("TITLE", "Doctor") will replace any text consisting of "[TITLE]" with "Doctor".

#### AddText(Rect, string)

All text inside 'target_region' will be deleted and replaced with 'replacement_text'.

##### Declaration

    public void AddText(Rect target_region, string replacement_text)

##### Parameters

Type | Name | Description
--- | --- | ---
Rect | target_region | The rectangle defining the area in which all text will be replaced by 'replacement_text'.
string | replacement_text | The new text that will replace the existing text in 'target_region'.

##### Remarks

The 'replacement_text' will be styled in the same font/color/style that is used by the original text. If there are multiple font styles, the most prevalent style will be used. Also, the 'replacement_text' will wrap within the 'target_region', but if it is too long, the overflow text will not be visible, and no surrounding content will be affected.

#### Destroy()

##### Declaration

    public void Destroy()

#### 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 |

#### ~ContentReplacer()

Releases all resources used by the ContentReplacer

##### Declaration

    protected ~ContentReplacer()

#### Process(Page)

Apply the replacement instructions to the target page. Subsequent calls to 'Process' can be made on other pages, and it will apply the same rules.

##### Declaration

    public void Process(Page page)

##### Parameters

Type | Name | Description
--- | --- | ---
Page | page | The page to apply the content replacement instructions to.

### Implements

IDisposable