paragraph.ParagraphFormat.FirstLineIndentChars = value;
Positive value: sets first-line indentation
Negative value: sets hanging indentation
When value is 0, using paragraph.Format.SetFirstLineIndentChars(0) method.

textBox.AspectRatioLocked = true; //The aspect ratio is not locked by default when a text box is added

picture.AspectRatioLocked = true; // The aspect ratio is locked by default when a picture is added

Spire.Presentation.FileFormat.Pptx2016
Spire.Presentation.FileFormat.Pptx2019

Presentation ppt = new Presentation();
IChart chart = ppt.Slides[0].Shapes.AppendChart(ChartType.ColumnClustered, new RectangleF(50, 50, 400, 400));

//Gets the PrimaryCategory axis
IChartAxis chartAxis = chart.PrimaryCategoryAxis;

//Set "Distance from axis"
chartAxis.LabelsDistance = 200;

//Save to file
ppt.SaveToFile(outputFile, FileFormat.Pptx2013);

PdfDocument doc = new PdfDocument();
PdfPageBase page = doc.Pages.Add(PdfPageSize.A4, new PdfMargins(20));
page.SetTabOrder(TabOrder.Structure);
PdfTaggedContent taggedContent = new PdfTaggedContent(doc);
taggedContent.SetLanguage("en-US");
taggedContent.SetTitle("test");
taggedContent.SetPdfUA1Identification();
PdfTrueTypeFont font = new PdfTrueTypeFont(new System.Drawing.Font("Times New Roman", 14), true);
PdfSolidBrush brush = new PdfSolidBrush(Color.Black);
PdfStructureElement document = taggedContent.StructureTreeRoot.AppendChildElement(PdfStandardStructTypes.Document);
PdfStructureElement heading1 = document.AppendChildElement(PdfStandardStructTypes.HeadingLevel1);
heading1.BeginMarkedContent(page);
string headingText = "What is a Tagged PDF?";
page.Canvas.DrawString(headingText, font, brush, new PointF(0, 0));
heading1.EndMarkedContent(page);
PdfStructureElement paragraph = document.AppendChildElement(PdfStandardStructTypes.Paragraph);
paragraph.BeginMarkedContent(page);
string paragraphText = ""Tagged PDF" doesn’t seem like a life-changing term. But for some, it is. For people who are " +
    "blind or have low vision and use assistive technology (such as screen readers and connected Braille displays) to " +
    "access information, an untagged PDF means they are missing out on information contained in the document because assistive " +
    "technology cannot "read" untagged PDFs.  Digital accessibility has opened up so many avenues to information that were once " +
    "closed to people with visual disabilities, but PDFs often get left out of the equation.";
RectangleF rect = new RectangleF(0, 30, page.Canvas.ClientSize.Width, page.Canvas.ClientSize.Height);
page.Canvas.DrawString(paragraphText, font, brush, rect);
paragraph.EndMarkedContent(page);
PdfStructureElement figure = document.AppendChildElement(PdfStandardStructTypes.Figure);
figure.BeginMarkedContent(page);
PdfImage image = PdfImage.FromFile(TestUtil.DataPath + "ImgFiles/Bug_3938.png");
page.Canvas.DrawImage(image, new PointF(0, 150));
figure.EndMarkedContent(page);

PdfStructureElement table = document.AppendChildElement(PdfStandardStructTypes.Table);
PdfTable pdfTable = new PdfTable();
pdfTable.Style.DefaultStyle.Font = font;
System.Data.DataTable dataTable = new System.Data.DataTable();
dataTable.Columns.Add("Name");
dataTable.Columns.Add("Age");
dataTable.Columns.Add("Sex");
dataTable.Rows.Add(new string[] { "John", "22", "Male" });
dataTable.Rows.Add(new string[] { "Katty", "25", "Female" });
pdfTable.DataSource = dataTable;
pdfTable.Style.ShowHeader = true;
pdfTable.StructureElement = table;
pdfTable.Draw(page.Canvas, new PointF(0, 280), 300f);

doc.SaveToFile("1.pdf");
doc.Dispose();

PdfDocument myPdf = new PdfDocument("test.pdf");
PdfPageBase page = myPdf .Pages[0];
PdfDestination dest = new PdfDestination(page, new PointF(-40f, -40f));
dest.Mode = PdfDestinationMode.FitV; 
PdfGoToAction gotoaction = new PdfGoToAction(dest);
myPdf.AfterOpenAction = gotoaction;
myPdf.ViewerPreferences.PageMode = PdfPageMode.UseOutlines;
myPdf.SaveToFile("FitBH.pdf");
myPdf.Close();