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Aspose.PDF for .NET是一种高PDF处理和解析API，用于在跨平台应用程序中执行文档管理和操作任务。API可以轻松用于生成、修改、转换、渲染、保护和打印PDF文档，而无需使用Adobe Acrobat。此外，API还提供PDF压缩选项，表格创建和操作，图形和图像功能，广泛的超链接功能，印章和水印任务，扩展的安全控制和自定义字体处理。

在接下来的系列教程中，将为开发者带来Aspose.PDF for .NET的一系列使用教程，例如进行文档间的转换，如何标记PDF文件，如何使用表单和图表等等。本文将介绍如何在设置文本格式，如行缩进、下划线、换行等等。

>>Aspose.PDF for .NET更新至最新版v20.11，欢迎下载体验。

添加删除线文本

TextState类提供了设置放置在PDF文档中的TextFragments格式的功能。您可以使用此类将文本格式设置为粗体，斜体，下划线，并在此版本开始时，API提供了将文本格式标记为Strikeout的功能。请尝试使用以下代码片段添加具有Strikeout格式的TextFragment。请使用完整的代码段：

// The path to the documents directory.
string dataDir = RunExamples.GetDataDir_AsposePdf_Text();
// Open document
Document pdfDocument = new Document();
// Get particular page
Page pdfPage = (Page)pdfDocument.Pages.Add();

// Create text fragment
TextFragment textFragment = new TextFragment("main text");
textFragment.Position = new Position(100, 600);

// Set text properties
textFragment.TextState.FontSize = 12;
textFragment.TextState.Font = FontRepository.FindFont("TimesNewRoman");
textFragment.TextState.BackgroundColor = Aspose.Pdf.Color.LightGray;
textFragment.TextState.ForegroundColor = Aspose.Pdf.Color.Red;
// Set StrikeOut property
textFragment.TextState.StrikeOut = true;
// Mark text as Bold
textFragment.TextState.FontStyle = FontStyles.Bold;

// Create TextBuilder object
TextBuilder textBuilder = new TextBuilder(pdfPage);
// Append the text fragment to the PDF page
textBuilder.AppendText(textFragment);


dataDir = dataDir + "AddStrikeOutText_out.pdf";

// Save resulting PDF document.
pdfDocument.Save(dataDir);

对文本应用渐变底纹

在用于文本编辑方案的API中，文本格式得到了进一步增强，现在您可以在PDF文档中添加带有图案色彩空间的文本。通过引入PatternColorSpace的新属性进一步增强了Aspose.Pdf.Color类，该属性可用于指定文本的底纹颜色。此新属性在文本中添加了不同的渐变底纹，例如“轴向底纹”，“径向（类型3）”底纹，如以下代码片段所示：

// The path to the documents directory.
string dataDir = RunExamples.GetDataDir_AsposePdf_Text();
            
using (Document pdfDocument = new Document(dataDir + "text_sample4.pdf"))
{
    TextFragmentAbsorber absorber = new TextFragmentAbsorber("Lorem ipsum");
    pdfDocument.Pages.Accept(absorber);

    TextFragment textFragment = absorber.TextFragments[1];

    // Create new color with pattern colorspace
    textFragment.TextState.ForegroundColor = new Aspose.Pdf.Color()
    {
        PatternColorSpace = new Aspose.Pdf.Drawing.GradientAxialShading(Color.Red, Color.Blue)
    };
    textFragment.TextState.Underline = true;

    pdfDocument.Save(dataDir + "text_out.pdf");
}

添加行缩进

用于.NET的Aspose.PDF将SubsequentLinesIndent属性提供给TextFormattingOptions类。在具有TextFragment和Paragraphs集合的PDF生成方案中，可用于指定行缩进。请使用以下代码段使用该属性：

// The path to the documents directory.
string dataDir = RunExamples.GetDataDir_AsposePdf_Text();
// Create new document object 
Aspose.Pdf.Document document = new Aspose.Pdf.Document();
Aspose.Pdf.Page page = document.Pages.Add();

Aspose.Pdf.Text.TextFragment text = new Aspose.Pdf.Text.TextFragment("A quick brown fox jumped over the lazy dog. A quick brown fox jumped over the lazy dog. A quick brown fox jumped over the lazy dog. A quick brown fox jumped over the lazy dog. A quick brown fox jumped over the lazy dog. A quick brown fox jumped over the lazy dog. A quick brown fox jumped over the lazy dog. A quick brown fox jumped over the lazy dog.");

// Initilize TextFormattingOptions for the text fragment and specify SubsequentLinesIndent value
text.TextState.FormattingOptions = new Aspose.Pdf.Text.TextFormattingOptions()
{
    SubsequentLinesIndent = 20
};

page.Paragraphs.Add(text);

text = new Aspose.Pdf.Text.TextFragment("Line2");
page.Paragraphs.Add(text);

text = new Aspose.Pdf.Text.TextFragment("Line3");
page.Paragraphs.Add(text);

text = new Aspose.Pdf.Text.TextFragment("Line4");
page.Paragraphs.Add(text);

text = new Aspose.Pdf.Text.TextFragment("Line5");
page.Paragraphs.Add(text);

document.Save(dataDir + "SubsequentIndent_out.pdf", Aspose.Pdf.SaveFormat.Pdf);

添加文字边框

以下代码段显示了如何使用TextBuilder和设置TextState的DrawTextRectangleBorder属性为文本添加边框：

// The path to the documents directory.
string dataDir = RunExamples.GetDataDir_AsposePdf_Text();
// Create new document object 
Document pdfDocument = new Document();
// Get particular page
Page pdfPage = (Page)pdfDocument.Pages.Add();
// Create text fragment
TextFragment textFragment = new TextFragment("main text");
textFragment.Position = new Position(100, 600);
// Set text properties
textFragment.TextState.FontSize = 12;
textFragment.TextState.Font = FontRepository.FindFont("TimesNewRoman");
textFragment.TextState.BackgroundColor = Aspose.Pdf.Color.LightGray;
textFragment.TextState.ForegroundColor = Aspose.Pdf.Color.Red;
// Set StrokingColor property for drawing border (stroking) around text rectangle
textFragment.TextState.StrokingColor = Aspose.Pdf.Color.DarkRed;
// Set DrawTextRectangleBorder property value to true
textFragment.TextState.DrawTextRectangleBorder = true;
TextBuilder tb = new TextBuilder(pdfPage);
tb.AppendText(textFragment);
// Save the document
pdfDocument.Save(dataDir + "PDFWithTextBorder_out.pdf");

添加下划线文字

以下代码段显示了如何在创建新的PDF文件时添加下划线文本。

// The path to the documents directory.
string dataDir = RunExamples.GetDataDir_AsposePdf_Text();

// Create documentation object
Document pdfDocument = new Document();
// Add age page to PDF document
pdfDocument.Pages.Add();
// Create TextBuilder for first page
TextBuilder tb = new TextBuilder(pdfDocument.Pages[1]);
// TextFragment with sample text
TextFragment fragment = new TextFragment("Test message");
// Set the font for TextFragment
fragment.TextState.Font = FontRepository.FindFont("Arial");
fragment.TextState.FontSize = 10;
// Set the formatting of text as Underline
fragment.TextState.Underline = true;
// Specify the position where TextFragment needs to be placed
fragment.Position = new Position(10, 800);
// Append TextFragment to PDF file
tb.AppendText(fragment);

dataDir = dataDir + "AddUnderlineText_out.pdf";

// Save resulting PDF document.
pdfDocument.Save(dataDir);

在添加的文本周围添加边框

可以控制所添加文本的外观。下例显示了如何在您添加的文本周围绘制边框，方法是在该文本周围绘制一个矩形。

// The path to the documents directory.
string dataDir = RunExamples.GetDataDir_AsposePdf_Text();

PdfContentEditor editor = new PdfContentEditor();
editor.BindPdf(dataDir + "input.pdf");
LineInfo lineInfo = new LineInfo();
lineInfo.LineWidth = 2;
lineInfo.VerticeCoordinate = new float[] { 0, 0, 100, 100, 50, 100 };
lineInfo.Visibility = true;
editor.CreatePolygon(lineInfo, 1, new System.Drawing.Rectangle(0, 0, 0, 0), "");

dataDir = dataDir + "AddingBorderAroundAddedText_out.pdf";

// Save resulting PDF document.
editor.Save(dataDir);

添加换行

TextFragment不支持文本内的换行。但是，为了通过换行符添加文本，请使用TextFragment和TextParagraph：

• 在TextFragment中使用“ \ r \ n”或Environment.NewLine而不是单个“ \ n”；
• 创建TextParagraph对象。它将添加带有行拆分的文本；
• 使用TextParagraph.AppendLine添加TextFragment；
• 使用TextBuilder.AppendParagraph添加TextParagraph。

// The path to the documents directory.
string dataDir = RunExamples.GetDataDir_AsposePdf_Text();
Aspose.Pdf.Document pdfApplicationDoc = new Aspose.Pdf.Document();
Aspose.Pdf.Page applicationFirstPage = (Aspose.Pdf.Page)pdfApplicationDoc.Pages.Add();

// Initialize new TextFragment with text containing required newline markers
Aspose.Pdf.Text.TextFragment textFragment = new Aspose.Pdf.Text.TextFragment("Applicant Name: " + Environment.NewLine + " Joe Smoe");

// Set text fragment properties if necessary
textFragment.TextState.FontSize = 12;
textFragment.TextState.Font = Aspose.Pdf.Text.FontRepository.FindFont("TimesNewRoman");
textFragment.TextState.BackgroundColor = Aspose.Pdf.Color.LightGray;
textFragment.TextState.ForegroundColor = Aspose.Pdf.Color.Red;

// Create TextParagraph object
TextParagraph par = new TextParagraph();

// Add new TextFragment to paragraph
par.AppendLine(textFragment);

// Set paragraph position
par.Position = new Aspose.Pdf.Text.Position(100, 600);

// Create TextBuilder object
TextBuilder textBuilder = new TextBuilder(applicationFirstPage);
// Add the TextParagraph using TextBuilder
textBuilder.AppendParagraph(par);


dataDir = dataDir + "AddNewLineFeed_out.pdf";

// Save resulting PDF document.
pdfApplicationDoc.Save(dataDir);

浮动框内容的文本对齐

Aspose.PDF支持为Floating Box元素内的内容设置文本对齐方式。如下面的代码示例所示，可以使用Aspose.Pdf.FloatingBox实例的对齐属性来实现此目的。

// The path to the documents directory.
string dataDir = RunExamples.GetDataDir_AsposePdf_Text();

Aspose.Pdf.Document doc = new Document();
doc.Pages.Add();

Aspose.Pdf.FloatingBox floatBox = new Aspose.Pdf.FloatingBox(100, 100);
floatBox.VerticalAlignment = VerticalAlignment.Bottom;
floatBox.HorizontalAlignment = Aspose.Pdf.HorizontalAlignment.Right;
floatBox.Paragraphs.Add(new TextFragment("FloatingBox_bottom"));
floatBox.Border = new Aspose.Pdf.BorderInfo(Aspose.Pdf.BorderSide.All, Aspose.Pdf.Color.Blue);
doc.Pages[1].Paragraphs.Add(floatBox);

Aspose.Pdf.FloatingBox floatBox1 = new Aspose.Pdf.FloatingBox(100, 100);
floatBox1.VerticalAlignment = VerticalAlignment.Center;
floatBox1.HorizontalAlignment = Aspose.Pdf.HorizontalAlignment.Right;
floatBox1.Paragraphs.Add(new TextFragment("FloatingBox_center"));
floatBox1.Border = new Aspose.Pdf.BorderInfo(Aspose.Pdf.BorderSide.All, Aspose.Pdf.Color.Blue);
doc.Pages[1].Paragraphs.Add(floatBox1);

Aspose.Pdf.FloatingBox floatBox2 = new Aspose.Pdf.FloatingBox(100, 100);
floatBox2.VerticalAlignment = VerticalAlignment.Top;
floatBox2.HorizontalAlignment = Aspose.Pdf.HorizontalAlignment.Right;
floatBox2.Paragraphs.Add(new TextFragment("FloatingBox_top"));
floatBox2.Border = new Aspose.Pdf.BorderInfo(Aspose.Pdf.BorderSide.All, Aspose.Pdf.Color.Blue);
doc.Pages[1].Paragraphs.Add(floatBox2);

doc.Save(dataDir + "FloatingBox_alignment_review_out.pdf");