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Change the fill color of a shape in a presentation

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

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))

With v3.0.0+ the Close() method has been removed in favor of relying on the using statement. This ensures that the Dispose() method 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 (<spTree/>) 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/IEC 29500: 2016

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 shape on the first slide.

// Get the relationship ID of the first slide.
PresentationPart presentationPart = ppt.PresentationPart ?? ppt.AddPresentationPart();
presentationPart.Presentation.SlideIdList ??= new SlideIdList();
SlideId? slideId = presentationPart.Presentation.SlideIdList.GetFirstChild<SlideId>();

if (slideId is not null)
{
    string? relId = slideId.RelationshipId;

    if (relId is not null)
    {
        // Get the slide part from the relationship ID.
        SlidePart slidePart = (SlidePart)presentationPart.GetPartById(relId);

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 shape properties of the shape and the solid fill reference of the shape properties, and assigns a new fill color to the shape. There is no need to explicitly save the file when inside of a using.

// Get or add the shape tree
slidePart.Slide.CommonSlideData ??= new CommonSlideData();

// Get the shape tree that contains the shape to change.
slidePart.Slide.CommonSlideData.ShapeTree ??= new ShapeTree();

// Get the first shape in the shape tree.
Shape? shape = slidePart.Slide.CommonSlideData.ShapeTree.GetFirstChild<Shape>();

if (shape is not null)
{
    // Get or add the shape properties element of the shape.
    shape.ShapeProperties ??= new ShapeProperties();

    // Get or add the fill reference.
    Drawing.SolidFill? solidFill = shape.ShapeProperties.GetFirstChild<Drawing.SolidFill>();

    if (solidFill is null)
    {
        shape.ShapeProperties.AddChild(new Drawing.SolidFill());
        solidFill = shape.ShapeProperties.GetFirstChild<Drawing.SolidFill>();
    }

    // Set the fill color to SchemeColor
    solidFill!.SchemeColor = new Drawing.SchemeColor() { Val = Drawing.SchemeColorValues.Accent2 };
}

Sample Code

Following is the complete sample code that you can use to change the fill color of a shape in a presentation.

// Change the fill color of a shape.
// The test file must have a shape on the first slide.
static void SetPPTShapeColor(string docName)
{
    using (PresentationDocument ppt = PresentationDocument.Open(docName, true))
    {
        // Get the relationship ID of the first slide.
        PresentationPart presentationPart = ppt.PresentationPart ?? ppt.AddPresentationPart();
        presentationPart.Presentation.SlideIdList ??= new SlideIdList();
        SlideId? slideId = presentationPart.Presentation.SlideIdList.GetFirstChild<SlideId>();

        if (slideId is not null)
        {
            string? relId = slideId.RelationshipId;

            if (relId is not null)
            {
                // Get the slide part from the relationship ID.
                SlidePart slidePart = (SlidePart)presentationPart.GetPartById(relId);
                // Get or add the shape tree
                slidePart.Slide.CommonSlideData ??= new CommonSlideData();

                // Get the shape tree that contains the shape to change.
                slidePart.Slide.CommonSlideData.ShapeTree ??= new ShapeTree();

                // Get the first shape in the shape tree.
                Shape? shape = slidePart.Slide.CommonSlideData.ShapeTree.GetFirstChild<Shape>();

                if (shape is not null)
                {
                    // Get or add the shape properties element of the shape.
                    shape.ShapeProperties ??= new ShapeProperties();

                    // Get or add the fill reference.
                    Drawing.SolidFill? solidFill = shape.ShapeProperties.GetFirstChild<Drawing.SolidFill>();

                    if (solidFill is null)
                    {
                        shape.ShapeProperties.AddChild(new Drawing.SolidFill());
                        solidFill = shape.ShapeProperties.GetFirstChild<Drawing.SolidFill>();
                    }

                    // Set the fill color to SchemeColor
                    solidFill!.SchemeColor = new Drawing.SchemeColor() { Val = Drawing.SchemeColorValues.Accent2 };
                }
            }
        }
    }
}

See also