How to: Change the Fill Color of a Shape in a Presentation

Artigo
07/30/2014

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

In this article
Getting a Presentation Object
The Structure of the Shape Tree
How the Sample Code Works
Sample Code

This topic shows how to use the classes in the Open XML SDK 2.0 for Microsoft Office to change the fill color of a shape on the first slide in a presentation programmatically.

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

using DocumentFormat.OpenXml.Presentation;
using DocumentFormat.OpenXml.Packaging;
using DocumentFormat.OpenXml;
using Drawing = DocumentFormat.OpenXml.Drawing;

Imports DocumentFormat.OpenXml.Presentation
Imports DocumentFormat.OpenXml.Packaging
Imports DocumentFormat.OpenXml
Imports Drawing = DocumentFormat.OpenXml.Drawing

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 the Open method that uses a file path, and a Boolean value as the second parameter to specify whether a document is editable. To open a document for read/write, specify the value true for this parameter as shown in the following using statement. In this code, the file parameter is a string that represents the path for the file from which you want to open the document.

using (PresentationDocument ppt = PresentationDocument.Open(docName, true))
{
    // Insert other code here.
}

Using ppt As PresentationDocument = PresentationDocument.Open(docName, True)
    ' Insert 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 ppt.

The Structure of the Shape Tree

The basic document structure of a PresentationML document consists of a number of parts, among which is the Shape Tree (sp Tree) element.

The following text from the ISO/IEC 29500 specification introduces the overall form of a PresentationML package.

This element specifies all shapes within a slide. Contained within here are all the shapes, either grouped or not, that can be referenced on a given slide. As most objects within a slide are shapes, this represents the majority of content within a slide. Text and effects are attached to shapes that are contained within the spTree element.[Example: Consider the following PresentationML slide

<p:sld>
  <p:cSld>
    <p:spTree>
      <p:nvGrpSpPr>
      ..
      </p:nvGrpSpPr>
      <p:grpSpPr>
      ..
      </p:grpSpPr>
      <p:sp>
      ..
      </p:sp>
    </p:spTree>
  </p:cSld>
  ..
</p:sld>

In the above example the shape tree specifies all the shape properties for this slide. end example]© ISO/IEC29500: 2008.

The following table lists the child elements of the Shape Tree along with the description of each.

Element	Description
cxnSp	Connection Shape
extLst	Extension List with Modification Flag
graphicFrame	Graphic Frame
grpSp	Group Shape
grpSpPr	Group Shape Properties
nvGrpSpPr	Non-Visual Properties for a Group Shape
pic	Picture
sp	Shape

The following XML Schema fragment defines the contents of this element.

<complexType name="CT_GroupShape">
   <sequence>
       <element name="nvGrpSpPr" type="CT_GroupShapeNonVisual" minOccurs="1" maxOccurs="1"/>
       <element name="grpSpPr" type="a:CT_GroupShapeProperties" minOccurs="1" maxOccurs="1"/>
       <choice minOccurs="0" maxOccurs="unbounded">
          <element name="sp" type="CT_Shape"/>
          <element name="grpSp" type="CT_GroupShape"/>
          <element name="graphicFrame" type="CT_GraphicalObjectFrame"/>
          <element name="cxnSp" type="CT_Connector"/>
          <element name="pic" type="CT_Picture"/>
       </choice>
       <element name="extLst" type="CT_ExtensionListModify" minOccurs="0" maxOccurs="1"/>
   </sequence>
</complexType>

How the Sample Code Works

After opening the presentation file for read/write access in the using statement, the code gets the presentation part from the presentation document. Then it gets the relationship ID of the first slide, and gets the slide part from the relationship ID.

Note

The test file must have a filled shape as the first shape on the first slide.

using (PresentationDocument ppt = PresentationDocument.Open(docName, true))
{
    // Get the relationship ID of the first slide.
    PresentationPart part = ppt.PresentationPart;
    OpenXmlElementList slideIds = part.Presentation.SlideIdList.ChildElements;
    string relId = (slideIds[0] as SlideId).RelationshipId;

    // Get the slide part from the relationship ID.
    SlidePart slide = (SlidePart)part.GetPartById(relId);

Using ppt As PresentationDocument = PresentationDocument.Open(docName, True)

    ' Get the relationship ID of the first slide.
    Dim part As PresentationPart = ppt.PresentationPart
    Dim slideIds As OpenXmlElementList = part.Presentation.SlideIdList.ChildElements
    Dim relId As String = CType(slideIds(0), SlideId).RelationshipId

    ' Get the slide part from the relationship ID.
    Dim slide As SlidePart = CType(part.GetPartById(relId), SlidePart)

The code then gets the shape tree that contains the shape whose fill color is to be changed, and gets the first shape in the shape tree. It then gets the style of the shape and the fill reference of the style, and assigns a new fill color to the shape. Finally it saves the modified presentation.

if (slide != null)
{
    // Get the shape tree that contains the shape to change.
    ShapeTree tree = slide.Slide.CommonSlideData.ShapeTree;

    // Get the first shape in the shape tree.
    Shape shape = tree.GetFirstChild<Shape>();

    if (shape != null)
    {
        // Get the style of the shape.
        ShapeStyle style = shape.ShapeStyle;

        // Get the fill reference.
        Drawing.FillReference fillRef = style.FillReference;

        // Set the fill color to SchemeColor Accent 6;
        fillRef.SchemeColor = new Drawing.SchemeColor();
        fillRef.SchemeColor.Val = Drawing.SchemeColorValues.Accent6;

        // Save the modified slide.
        slide.Slide.Save();
    }
}

If (Not (slide) Is Nothing) Then

    ' Get the shape tree that contains the shape to change.
    Dim tree As ShapeTree = slide.Slide.CommonSlideData.ShapeTree

    ' Get the first shape in the shape tree.
    Dim shape As Shape = tree.GetFirstChild(Of Shape)()

    If (Not (shape) Is Nothing) Then

        ' Get the style of the shape.
        Dim style As ShapeStyle = shape.ShapeStyle

        ' Get the fill reference.
        Dim fillRef As Drawing.FillReference = style.FillReference

        ' Set the fill color to SchemeColor Accent 6;
        fillRef.SchemeColor = New Drawing.SchemeColor
        fillRef.SchemeColor.Val = Drawing.SchemeColorValues.Accent6

        ' Save the modified slide.
        slide.Slide.Save()
    End If
End If

Sample Code

Following is the complete sample code that you can use to change the fill color of a shape in a presentation. In your program, you can invoke the method SetPPTShapeColor to change the fill color in the file "Myppt3.pptx" by using the following call.

string docName = @"C:\Users\Public\Documents\Myppt3.pptx";
SetPPTShapeColor(docName);

Dim docName As String = "C:\Users\Public\Documents\Myppt3.pptx"
SetPPTShapeColor(docName)

After running the program, examine the file "Myppt3.pptx" to see the change in the fill color.

// Change the fill color of a shape.
// The test file must have a filled shape as the first shape on the first slide.
public static void SetPPTShapeColor(string docName)
{
    using (PresentationDocument ppt = PresentationDocument.Open(docName, true))
    {
        // Get the relationship ID of the first slide.
        PresentationPart part = ppt.PresentationPart;
        OpenXmlElementList slideIds = part.Presentation.SlideIdList.ChildElements;
        string relId = (slideIds[0] as SlideId).RelationshipId;

        // Get the slide part from the relationship ID.
        SlidePart slide = (SlidePart)part.GetPartById(relId);

        if (slide != null)
        {
            // Get the shape tree that contains the shape to change.
            ShapeTree tree = slide.Slide.CommonSlideData.ShapeTree;

            // Get the first shape in the shape tree.
            Shape shape = tree.GetFirstChild<Shape>();

            if (shape != null)
            {
                // Get the style of the shape.
                ShapeStyle style = shape.ShapeStyle;

                // Get the fill reference.
                Drawing.FillReference fillRef = style.FillReference;

                // Set the fill color to SchemeColor Accent 6;
                fillRef.SchemeColor = new Drawing.SchemeColor();
                fillRef.SchemeColor.Val = Drawing.SchemeColorValues.Accent6;

                // Save the modified slide.
                slide.Slide.Save();
            }
        }
    }
}

' Change the fill color of a shape.
' The test file must have a filled shape as the first shape on the first slide.
Public Sub SetPPTShapeColor(ByVal docName As String)
    Using ppt As PresentationDocument = PresentationDocument.Open(docName, True)
        ' Get the relationship ID of the first slide.
        Dim part As PresentationPart = ppt.PresentationPart
        Dim slideIds As OpenXmlElementList = part.Presentation.SlideIdList.ChildElements
        Dim relId As String = TryCast(slideIds(0), SlideId).RelationshipId

        ' Get the slide part from the relationship ID.
        Dim slide As SlidePart = DirectCast(part.GetPartById(relId), SlidePart)

        If slide IsNot Nothing Then
            ' Get the shape tree that contains the shape to change.
            Dim tree As ShapeTree = slide.Slide.CommonSlideData.ShapeTree

            ' Get the first shape in the shape tree.
            Dim shape As Shape = tree.GetFirstChild(Of Shape)()

            If shape IsNot Nothing Then
                ' Get the style of the shape.
                Dim style As ShapeStyle = shape.ShapeStyle

                ' Get the fill reference.
                Dim fillRef As Drawing.FillReference = style.FillReference

                ' Set the fill color to SchemeColor Accent 6;
                fillRef.SchemeColor = New Drawing.SchemeColor()
                fillRef.SchemeColor.Val = Drawing.SchemeColorValues.Accent6

                ' Save the modified slide.
                slide.Slide.Save()
            End If
        End If
    End Using
End Sub

Compartilhar via

How to: Change the Fill Color of a Shape in a Presentation

Getting a Presentation Object

The Structure of the Shape Tree

How the Sample Code Works

Sample Code

See Also

Reference

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