itextsharp

插入图片

using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

class Program
{
    static void Main(string[] args)
    {
        using (Stream inputPdfStream = new FileStream("input.pdf", FileMode.Open, FileAccess.Read, FileShare.Read))
        using (Stream inputImageStream = new FileStream("some_image.jpg", FileMode.Open, FileAccess.Read, FileShare.Read))
        using (Stream outputPdfStream = new FileStream("result.pdf", FileMode.Create, FileAccess.Write, FileShare.None))
        {
            var reader = new PdfReader(inputPdfStream);
            var stamper = new PdfStamper(reader, outputPdfStream);
            var pdfContentByte = stamper.GetOverContent(1);

            Image image = Image.GetInstance(inputImageStream);
            image.SetAbsolutePosition(100, 100);
            pdfContentByte.AddImage(image);
            stamper.Close();
        }
    }
}

iTextSharp.text.Image

SetAbsolutePosition()有2个参数，第一个参数是X轴坐标，第二个参数是Y轴坐标，使用PDF坐标系，文档的左下角为坐标原点。
ScalePercent() 缩放比，

获取表单位置

IList<AcroFields.FieldPosition> fieldPositions = fields.GetFieldPositions("fieldNameInThePDF");
if (fieldPositions == null || fieldPositions.Count <= 0) throw new ApplicationException("Error locating field");
AcroFields.FieldPosition fieldPosition = fieldPositions[0];
left = fieldPosition.position.Left;
right = fieldPosition.position.Right;
top = fieldPosition.position.Top;
bottom = fieldPosition.position.Bottom;
if (rotation == 90)
{
    left = fieldPosition.position.Bottom;
    right = fieldPosition.position.Top;
    top = pageSize.Right - fieldPosition.position.Left;
    bottom = pageSize.Right - fieldPosition.position.Right;
}

 获取文字位置

public class RectAndText { 
    public iTextSharp.text.Rectangle Rect; 
    public String Text; 
    public RectAndText(iTextSharp.text.Rectangle rect, String text) { 
     this.Rect = rect; 
     this.Text = text; 
    } 
} 

public class MyLocationTextExtractionStrategy : LocationTextExtractionStrategy { 
    //Hold each coordinate 
    public List<RectAndText> myPoints = new List<RectAndText>(); 

    //Automatically called for each chunk of text in the PDF 
    public override void RenderText(TextRenderInfo renderInfo) { 
     base.RenderText(renderInfo); 

     //Get the bounding box for the chunk of text 
     var bottomLeft = renderInfo.GetDescentLine().GetStartPoint(); 
     var topRight = renderInfo.GetAscentLine().GetEndPoint(); 

     //Create a rectangle from it 
     var rect = new iTextSharp.text.Rectangle(
               bottomLeft[Vector.I1], 
               bottomLeft[Vector.I2], 
               topRight[Vector.I1], 
               topRight[Vector.I2] 
               ); 

     //Add this to our main collection 
     this.myPoints.Add(new RectAndText(rect, renderInfo.GetText())); 
    } 
} 

 文字位置使用代码

//Create an instance of our strategy 
var t = new MyLocationTextExtractionStrategy(); 

//Parse page 1 of the document above 
using (var r = new PdfReader(testFile)) { 
    var ex = PdfTextExtractor.GetTextFromPage(r, 1, t); 
} 

//Loop through each chunk found 
foreach (var p in t.myPoints) { 
    Console.WriteLine(string.Format("Found text {0} at {1}x{2}", p.Text, p.Rect.Left, p.Rect.Bottom)); 
}