How to: Delete a Slide from a Presentation

Artigo
07/30/2014

Applies to: Excel 2010 | Office 2010 | PowerPoint 2010 | Word 2010

In this article
Getting a Presentation Object
Basic Presentation Document Structure
Counting the Number of Slides
Deleting a Specific Slide
Sample Code

This topic shows how to use the Open XML SDK 2.0 for Microsoft Office to delete a slide from a presentation programmatically. It also shows how to delete all references to the slide from any custom shows that may exist. To delete a specific slide in a presentation file you need to know first the number of slides in the presentation. Therefore the code in this how-to is divided into two parts. The first is counting the number of slides, and the second is deleting a slide at a specific index.

Note

Deleting a slide from more complex presentations, such as those that contain outline view settings, for example, may require additional steps.

The following assembly directives are required to compile the code in this topic.

using System;
using System.Collections.Generic;
using System.Linq;
using DocumentFormat.OpenXml.Presentation;
using DocumentFormat.OpenXml.Packaging;

Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports DocumentFormat.OpenXml.Presentation
Imports DocumentFormat.OpenXml.Packaging

Getting a Presentation Object

In the Open XML SDK, the PresentationDocument class represents a presentation document package. To work with a presentation document, first create an instance of the PresentationDocument class, and then work with that instance. To create the class instance from the document call one of the Open method overloads. The code in this topic uses the PresentationDocument.Open(String, Boolean) method, which takes a file path as the first parameter to specify the file to open, and a Boolean value as the second parameter to specify whether a document is editable. Set this second parameter to false to open the file for read-only access, or true if you want to open the file for read/write access. The code in this topic opens the file twice, once to count the number of slides and once to delete a specific slide. When you count the number of slides in a presentation, it is best to open the file for read-only access to protect the file against accidental writing. The following using statement opens the file for read-only access. In this code example, the presentationFile parameter is a string that represents the path for the file from which you want to open the document.

// Open the presentation as read-only.
using (PresentationDocument presentationDocument = PresentationDocument.Open(presentationFile, false))
{
    // Insert other code here.
}

' Open the presentation as read-only.
Using presentationDocument As PresentationDocument = PresentationDocument.Open(presentationFile, False)
    ' Insert other code here.
End Using

To delete a slide from the presentation file, open it for read/write access as shown in the following using statement.

// Open the source document as read/write.
using (PresentationDocument presentationDocument = PresentationDocument.Open(presentationFile, true))
{
    // Place other code here.
}

' Open the source document as read/write.
Using presentationDocument As PresentationDocument = PresentationDocument.Open(presentationFile, True)
    ' Place other code here.
End Using

The using statement provides a recommended alternative to the typical .Open, .Save, .Close sequence. It ensures that the Dispose method (internal method used by the Open XML SDK to clean up resources) is automatically called when the closing brace is reached. The block that follows the using statement establishes a scope for the object that is created or named in the using statement, in this case presentationDocument.

Basic Presentation Document Structure

The basic document structure of a PresentationML document consists of the main part that contains the presentation definition. The following text from the ISO/IEC 29500 specification introduces the overall form of a PresentationML package.

A PresentationML package’s main part starts with a presentation root element. That element contains a presentation, which, in turn, refers to a slide list, a slide master list, a notes master list, and a handout master list. The slide list refers to all of the slides in the presentation; the slide master list refers to the entire slide masters used in the presentation; the notes master contains information about the formatting of notes pages; and the handout master describes how a handout looks. A handout is a printed set of slides that can be provided to an audience for future reference.As well as text and graphics, each slide can contain comments and notes, can have a layout, and can be part of one or more custom presentations. (A comment is an annotation intended for the person maintaining the presentation slide deck. A note is a reminder or piece of text intended for the presenter or the audience.)Other features that a PresentationML document can include the following: animation, audio, video, and transitions between slides.A PresentationML document is not stored as one large body in a single part. Instead, the elements that implement certain groupings of functionality are stored in separate parts. For example, all comments in a document are stored in one comment part while each slide has its own part.© ISO/IEC29500: 2008.

This following XML code segment represents a presentation that contains two slides denoted by the IDs 267 and 256.

<p:presentation xmlns:p="…" … > 
   <p:sldMasterIdLst>
      <p:sldMasterId
         xmlns:rel="http://…/relationships" rel:id="rId1"/>
   </p:sldMasterIdLst>
   <p:notesMasterIdLst>
      <p:notesMasterId
         xmlns:rel="http://…/relationships" rel:id="rId4"/>
   </p:notesMasterIdLst>
   <p:handoutMasterIdLst>
      <p:handoutMasterId
         xmlns:rel="http://…/relationships" rel:id="rId5"/>
   </p:handoutMasterIdLst>
   <p:sldIdLst>
      <p:sldId id="267"
         xmlns:rel="http://…/relationships" rel:id="rId2"/>
      <p:sldId id="256"
         xmlns:rel="http://…/relationships" rel:id="rId3"/>
   </p:sldIdLst>
       <p:sldSz cx="9144000" cy="6858000"/>
   <p:notesSz cx="6858000" cy="9144000"/>
</p:presentation>

Using the Open XML SDK 2.0, you can create document structure and content using strongly-typed classes that correspond to PresentationML elements. You can find these classes in the DocumentFormat.OpenXml.Presentation namespace. The following table lists the class names of the classes that correspond to the sld, sldLayout, sldMaster, and notesMaster elements.

PresentationML Element	Open XML SDK 2.0 Class	Description
sld	Slide	Presentation Slide. It is the root element of SlidePart.
sldLayout	SlideLayout	Slide Layout. It is the root element of SlideLayoutPart.
sldMaster	SlideMaster	Slide Master. It is the root element of SlideMasterPart.
notesMaster	NotesMaster	Notes Master (or handoutMaster). It is the root element of NotesMasterPart.

Counting the Number of Slides

The sample code consists of two overloads of the CountSlides method. The first overload uses a string parameter and the second overload uses a PresentationDocument parameter. In the first CountSlides method, the sample code opens the presentation document in the using statement. Then it passes the PresentationDocument object to the second CountSlides method, which returns an integer number that represents the number of slides in the presentation.

// Pass the presentation to the next CountSlides method
// and return the slide count.
return CountSlides(presentationDocument);

' Pass the presentation to the next CountSlides method
' and return the slide count.
Return CountSlides(presentationDocument)

In the second CountSlides method, the code verifies that the PresentationDocument object passed in is not null, and if it is not, it gets a PresentationPart object from the PresentationDocument object. By using the SlideParts the code gets the slideCount and returns it.

// Check for a null document object.
if (presentationDocument == null)
{
    throw new ArgumentNullException("presentationDocument");
}

int slidesCount = 0;

// Get the presentation part of document.
PresentationPart presentationPart = presentationDocument.PresentationPart;

// Get the slide count from the SlideParts.
if (presentationPart != null)
{
    slidesCount = presentationPart.SlideParts.Count();
}
// Return the slide count to the previous method.
return slidesCount;

' Check for a null document object.
If presentationDocument Is Nothing Then
    Throw New ArgumentNullException("presentationDocument")
End If

Dim slidesCount As Integer = 0

' Get the presentation part of document.
Dim presentationPart As PresentationPart = presentationDocument.PresentationPart

' Get the slide count from the SlideParts.
If presentationPart IsNot Nothing Then
    slidesCount = presentationPart.SlideParts.Count()
End If
' Return the slide count to the previous method.
Return slidesCount

Deleting a Specific Slide

The code for deleting a slide uses two overloads of the DeleteSlide method. The first overloaded DeleteSlide method takes two parameters: a string that represents the presentation file name and path, and an integer that represents the zero-based index position of the slide to delete. It opens the presentation file for read/write access, gets a PresentationDocument object, and then passes that object and the index number to the next overloaded DeleteSlide method, which performs the deletion.

// Get the presentation object and pass it to the next DeleteSlide method.
public static void DeleteSlide(string presentationFile, int slideIndex)
{
    // Open the source document as read/write.

    using (PresentationDocument presentationDocument = PresentationDocument.Open(presentationFile, true))
    {
      // Pass the source document and the index of the slide to be deleted to the next DeleteSlide method.
      DeleteSlide(presentationDocument, slideIndex);
    }
}

' Check for a null document object.
If presentationDocument Is Nothing Then
    Throw New ArgumentNullException("presentationDocument")
End If

Dim slidesCount As Integer = 0

' Get the presentation part of document.
Dim presentationPart As PresentationPart = presentationDocument.PresentationPart

' Get the slide count from the SlideParts.
If presentationPart IsNot Nothing Then
    slidesCount = presentationPart.SlideParts.Count()
End If
' Return the slide count to the previous method.
Return slidesCount

The first section of the second overloaded DeleteSlide method uses the CountSlides method to get the number of slides in the presentation. Then, it gets the list of slide IDs in the presentation, identifies the specified slide in the slide list, and removes the slide from the slide list.

// Delete the specified slide from the presentation.
public static void DeleteSlide(PresentationDocument presentationDocument, int slideIndex)
{
    if (presentationDocument == null)
    {
        throw new ArgumentNullException("presentationDocument");
    }

    // Use the CountSlides sample to get the number of slides in the presentation.
    int slidesCount = CountSlides(presentationDocument);

    if (slideIndex < 0 || slideIndex >= slidesCount)
    {
        throw new ArgumentOutOfRangeException("slideIndex");
    }

    // Get the presentation part from the presentation document. 
    PresentationPart presentationPart = presentationDocument.PresentationPart;

    // Get the presentation from the presentation part.
    Presentation presentation = presentationPart.Presentation;

    // Get the list of slide IDs in the presentation.
    SlideIdList slideIdList = presentation.SlideIdList;

    // Get the slide ID of the specified slide
    SlideId slideId = slideIdList.ChildElements[slideIndex] as SlideId;

    // Get the relationship ID of the slide.
    string slideRelId = slideId.RelationshipId;

    // Remove the slide from the slide list.
    slideIdList.RemoveChild(slideId);

' Delete the specified slide from the presentation.
Public Shared Sub DeleteSlide(ByVal presentationDocument As 
    If presentationDocument Is Nothing Then
        Throw New ArgumentNullException("presentationDocument")
    End If

    ' Use the CountSlides sample to get the number of slides in the presentation.
    Dim slidesCount As Integer = CountSlides(presentationDocument)

    If slideIndex < 0 OrElse slideIndex >= slidesCount Then
        Throw New ArgumentOutOfRangeException("slideIndex")
    End If

    ' Get the presentation part from the presentation document. 
    Dim presentationPart As PresentationPart = presentationDocument.PresentationPart

    ' Get the presentation from the presentation part.
    Dim presentation As Presentation = presentationPart.Presentation

    ' Get the list of slide IDs in the presentation.
    Dim slideIdList As SlideIdList = presentation.SlideIdList

    ' Get the slide ID of the specified slide
    Dim slideId As SlideId = TryCast(slideIdList.ChildElements(slideIndex), SlideId)

    ' Get the relationship ID of the slide.
    Dim slideRelId As String = slideId.RelationshipId

    ' Remove the slide from the slide list.
    slideIdList.RemoveChild(slideId)

The next section of the second overloaded DeleteSlide method removes all references to the deleted slide from custom shows. It does that by iterating through the list of custom shows and through the list of slides in each custom show. It then declares and instantiates a linked list of slide list entries, and finds references to the deleted slide by using the relationship ID of that slide. It adds those references to the list of slide list entries, and then removes each such reference from the slide list of its respective custom show.

// Remove references to the slide from all custom shows.
if (presentation.CustomShowList != null)
{
    // Iterate through the list of custom shows.
    foreach (var customShow in presentation.CustomShowList.Elements<CustomShow>())
    {
        if (customShow.SlideList != null)
        {
            // Declare a link list of slide list entries.
            LinkedList<SlideListEntry> slideListEntries = new LinkedList<SlideListEntry>();
            foreach (SlideListEntry slideListEntry in customShow.SlideList.Elements())
            {
                // Find the slide reference to remove from the custom show.
                if (slideListEntry.Id != null && slideListEntry.Id == slideRelId)
                {
                    slideListEntries.AddLast(slideListEntry);
                }
            }

            // Remove all references to the slide from the custom show.
            foreach (SlideListEntry slideListEntry in slideListEntries)
            {
                customShow.SlideList.RemoveChild(slideListEntry);
            }
        }
    }
}

' Remove references to the slide from all custom shows.
If presentation.CustomShowList IsNot Nothing Then
    ' Iterate through the list of custom shows.
    For Each customShow In presentation.CustomShowList.Elements(Of CustomShow)()
        If customShow.SlideList IsNot Nothing Then
            ' Declare a link list of slide list entries.
            Dim slideListEntries As New LinkedList(Of SlideListEntry)()
            For Each slideListEntry As SlideListEntry In customShow.SlideList.Elements()
                ' Find the slide reference to remove from the custom show.
                If slideListEntry.Id IsNot Nothing AndAlso slideListEntry.Id = slideRelId Then
                    slideListEntries.AddLast(slideListEntry)
                End If
            Next slideListEntry

            ' Remove all references to the slide from the custom show.
            For Each slideListEntry As SlideListEntry In slideListEntries
                customShow.SlideList.RemoveChild(slideListEntry)
            Next slideListEntry
        End If
    Next customShow
End If

Finally, the code saves the modified presentation, and deletes the slide part for the deleted slide.

// Save the modified presentation.
presentation.Save();

// Get the slide part for the specified slide.
SlidePart slidePart = presentationPart.GetPartById(slideRelId) as SlidePart;

// Remove the slide part.
presentationPart.DeletePart(slidePart);
}

' Save the modified presentation.
presentation.Save()

' Get the slide part for the specified slide.
Dim slidePart As SlidePart = TryCast(presentationPart.GetPartById(slideRelId), SlidePart)

' Remove the slide part.
presentationPart.DeletePart(slidePart)
End Sub

Sample Code

The following is the complete sample code for the two overloaded methods, CountSlides and DeleteSlide. To use the code, you can use the following call as an example to delete the slide at index 2 in the presentation file "Myppt6.pptx."

DeleteSlide(@"C:\Users\Public\Documents\Myppt6.pptx", 2);

DeleteSlide("C:\Users\Public\Documents\Myppt6.pptx", 0)

You can also use the following call to count the number of slides in the presentation.

Console.WriteLine("Number of slides = {0}",
CountSlides(@"C:\Users\Public\Documents\Myppt6.pptx"));

Console.WriteLine("Number of slides = {0}", _
CountSlides("C:\Users\Public\Documents\Myppt6.pptx"))

It might be a good idea to count the number of slides before and after performing the deletion.

Following is the complete sample code in both C# and Visual Basic.

// Get the presentation object and pass it to the next CountSlides method.
public static int CountSlides(string presentationFile)
{
    // Open the presentation as read-only.
    using (PresentationDocument presentationDocument = PresentationDocument.Open(presentationFile, false))
    {
        // Pass the presentation to the next CountSlide method
        // and return the slide count.
        return CountSlides(presentationDocument);
    }
}

// Count the slides in the presentation.
public static int CountSlides(PresentationDocument presentationDocument)
{
    // Check for a null document object.
    if (presentationDocument == null)
    {
        throw new ArgumentNullException("presentationDocument");
    }

    int slidesCount = 0;

    // Get the presentation part of document.
    PresentationPart presentationPart = presentationDocument.PresentationPart;

    // Get the slide count from the SlideParts.
    if (presentationPart != null)
    {
         slidesCount = presentationPart.SlideParts.Count();
     }

    // Return the slide count to the previous method.
    return slidesCount;
}
//
// Get the presentation object and pass it to the next DeleteSlide method.
public static void DeleteSlide(string presentationFile, int slideIndex)
{
    // Open the source document as read/write.

    using (PresentationDocument presentationDocument = PresentationDocument.Open(presentationFile, true))
    {
      // Pass the source document and the index of the slide to be deleted to the next DeleteSlide method.
      DeleteSlide(presentationDocument, slideIndex);
    }
}  

// Delete the specified slide from the presentation.
public static void DeleteSlide(PresentationDocument presentationDocument, int slideIndex)
{
    if (presentationDocument == null)
    {
        throw new ArgumentNullException("presentationDocument");
    }

    // Use the CountSlides sample to get the number of slides in the presentation.
    int slidesCount = CountSlides(presentationDocument);

    if (slideIndex < 0 || slideIndex >= slidesCount)
    {
        throw new ArgumentOutOfRangeException("slideIndex");
    }

    // Get the presentation part from the presentation document. 
    PresentationPart presentationPart = presentationDocument.PresentationPart;

    // Get the presentation from the presentation part.
    Presentation presentation = presentationPart.Presentation;

    // Get the list of slide IDs in the presentation.
    SlideIdList slideIdList = presentation.SlideIdList;

    // Get the slide ID of the specified slide
    SlideId slideId = slideIdList.ChildElements[slideIndex] as SlideId;

    // Get the relationship ID of the slide.
    string slideRelId = slideId.RelationshipId;

    // Remove the slide from the slide list.
    slideIdList.RemoveChild(slideId);

//
    // Remove references to the slide from all custom shows.
    if (presentation.CustomShowList != null)
    {
        // Iterate through the list of custom shows.
        foreach (var customShow in presentation.CustomShowList.Elements<CustomShow>())
        {
            if (customShow.SlideList != null)
            {
                // Declare a link list of slide list entries.
                LinkedList<SlideListEntry> slideListEntries = new LinkedList<SlideListEntry>();
                foreach (SlideListEntry slideListEntry in customShow.SlideList.Elements())
                {
                    // Find the slide reference to remove from the custom show.
                    if (slideListEntry.Id != null && slideListEntry.Id == slideRelId)
                    {
                        slideListEntries.AddLast(slideListEntry);
                    }
                }

                // Remove all references to the slide from the custom show.
                foreach (SlideListEntry slideListEntry in slideListEntries)
                {
                    customShow.SlideList.RemoveChild(slideListEntry);
                }
            }
        }
    }

    // Save the modified presentation.
    presentation.Save();

    // Get the slide part for the specified slide.
    SlidePart slidePart = presentationPart.GetPartById(slideRelId) as SlidePart;

    // Remove the slide part.
    presentationPart.DeletePart(slidePart);
}

' Count the number of slides in the presentation.
Public Function CountSlides(ByVal presentationFile As String) As Integer
    ' Open the presentation as read-only.
    Using presentationDocument__1 As PresentationDocument = PresentationDocument.Open(presentationFile, False)
        ' Pass the presentation to the next CountSlides method
        ' and return the slide count.
        Return CountSlides(presentationDocument__1)
    End Using
End Function
' Count the slides in the presentation.
Public Function CountSlides(ByVal presentationDocument As PresentationDocument) As Integer
    ' Check for a null document object.
    If presentationDocument Is Nothing Then
        Throw New ArgumentNullException("presentationDocument")
    End If

    Dim slidesCount As Integer = 0

    ' Get the presentation part of document.
    Dim presentationPart As PresentationPart = presentationDocument.PresentationPart

    If presentationPart IsNot Nothing AndAlso presentationPart.Presentation IsNot Nothing Then
        ' Get the Presentation object from the presentation part.
        Dim presentation As Presentation = presentationPart.Presentation

        ' Verify that the presentation contains slides. 
        If presentation.SlideIdList IsNot Nothing Then

            ' Get the slide count from the slide ID list. 
            slidesCount = presentation.SlideIdList.Elements(Of SlideId)().Count()
        End If
    End If

    ' Return the slide count to the previous method.
    Return slidesCount
End Function
' Delete the specified slide from the presentation.
Public Sub DeleteSlide(ByVal presentationFile As String, ByVal slideIndex As Integer)

    ' Open the source document as read/write.
    Dim presentationDocument As PresentationDocument = presentationDocument.Open(presentationFile, True)

    Using (presentationDocument)

        ' Pass the source document and the index of the slide to be deleted to the next DeleteSlide method.
        DeleteSlide2(presentationDocument, slideIndex)

    End Using

End Sub
' Delete the specified slide in the presentation.
Public Sub DeleteSlide2(ByVal presentationDocument As PresentationDocument, ByVal slideIndex As Integer)
    If (presentationDocument Is Nothing) Then
        Throw New ArgumentNullException("presentationDocument")
    End If

    ' Use the CountSlides code example to get the number of slides in the presentation.
    Dim slidesCount As Integer = CountSlides(presentationDocument)
    If ((slideIndex < 0) OrElse (slideIndex >= slidesCount)) Then
        Throw New ArgumentOutOfRangeException("slideIndex")
    End If

    ' Get the presentation part from the presentation document.
    Dim presentationPart As PresentationPart = presentationDocument.PresentationPart

    ' Get the presentation from the presentation part. 
    Dim presentation As Presentation = presentationPart.Presentation

    ' Get the list of slide IDs in the presentation.
    Dim slideIdList As SlideIdList = presentation.SlideIdList

    ' Get the slide ID of the specified slide.
    Dim slideId As SlideId = CType(slideIdList.ChildElements(slideIndex), SlideId)

    ' Get the relationship ID of the specified slide.
    Dim slideRelId As String = slideId.RelationshipId

    ' Remove the slide from the slide list.
    slideIdList.RemoveChild(slideId)
    ' Remove references to the slide from all custom shows.
    If (Not (presentation.CustomShowList) Is Nothing) Then

        ' Iterate through the list of custom shows.
        For Each customShow As System.Object In presentation.CustomShowList.Elements(Of  _
                               DocumentFormat.OpenXml.Presentation.CustomShow)()

            If (Not (customShow.SlideList) Is Nothing) Then

                ' Declare a linked list.
                Dim slideListEntries As LinkedList(Of SlideListEntry) = New LinkedList(Of SlideListEntry)

                ' Iterate through all the slides in the custom show.
                For Each slideListEntry As SlideListEntry In customShow.SlideList.Elements

                    ' Find the slide reference to be removed from the custom show.
                    If ((Not (slideListEntry.Id) Is Nothing) _
                                AndAlso (slideListEntry.Id = slideRelId)) Then

                        ' Add that slide reference to the end of the linked list.
                        slideListEntries.AddLast(slideListEntry)
                    End If
                Next

                ' Remove references to the slide from the custom show.
                For Each slideListEntry As SlideListEntry In slideListEntries
                    customShow.SlideList.RemoveChild(slideListEntry)
                Next
            End If
        Next
    End If

    ' Save the change to the presentation part.
    presentation.Save()

    ' Get the slide part for the specified slide.
    Dim slidePart As SlidePart = CType(presentationPart.GetPartById(slideRelId), SlidePart)

    ' Remove the slide part.
    presentationPart.DeletePart(slidePart)

End Sub

Compartilhar via

How to: Delete a Slide from a Presentation

Getting a Presentation Object

Basic Presentation Document Structure

Counting the Number of Slides

Deleting a Specific Slide

Sample Code

See Also

Reference

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