在pdf文件中搜索文本，如果文本存在则返回坐标 [英] Search for a text in a pdf file and return the coordinates if the text exist

问题描述

我正在尝试在pdf文件中搜索文本，如果文本存在则返回坐标.我正在研究网络，发现可以使用itextsharp库来完成.

I am trying to search for a text in a pdf file and return the coordinates if the text exist. I was researching the net and find out that this can be done with the itextsharp library.

我找到了此代码，并试图对其进行修改以满足我的要求.如何将文件传递给此类.

I found this code and I am trying to modify it to meet my requirements. How can I pass my file to this class.

class Program
{
    static void Main(string[] args)
    {
        var testFile = @"test.pdf";
        //Create an instance of our strategy
        var t = new MyLocationTextExtractionStrategy("test");

        //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));
        }

        Console.Read();
    }
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>();

        //The string that we're searching for
        public String TextToSearchFor { get; set; }

        //How to compare strings
        public System.Globalization.CompareOptions CompareOptions { get; set; }

        public MyLocationTextExtractionStrategy(String textToSearchFor, System.Globalization.CompareOptions compareOptions = System.Globalization.CompareOptions.None)
        {
            this.TextToSearchFor = textToSearchFor;
            this.CompareOptions = compareOptions;
        }

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

            //See if the current chunk contains the text
            var startPosition = System.Globalization.CultureInfo.CurrentCulture.CompareInfo.IndexOf(renderInfo.GetText(), this.TextToSearchFor, this.CompareOptions);

            //If not found bail
            if (startPosition < 0)
            {
                return;
            }

            //Grab the individual characters
            var chars = renderInfo.GetCharacterRenderInfos().Skip(startPosition).Take(this.TextToSearchFor.Length).ToList();

            //Grab the first and last character
            var firstChar = chars.First();
            var lastChar = chars.Last();


            //Get the bounding box for the chunk of text
            var bottomLeft = firstChar.GetDescentLine().GetStartPoint();
            var topRight = lastChar.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, this.TextToSearchFor));
        }
    }

推荐答案

在我看来，PdfReader接受一个字符串，该字符串是您要读取的文件的路径.所以只需更改

Looks to me like PdfReader accepts a string which is a path to the file you want to read. So simply change

var testFile = @"test.pdf";

指向要使用的文件. (如果该路径不在应用程序的工作文件夹中，则可能需要添加完整路径)

to point to the file you want to use. (you may have to add a full path if it is not in the application's working folder)

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