C＃使用PdfSharp從PDF中提取文本

Question

是否有可能使用PdfSharp從PDF文件中提取純文本？ 我不想使用iTextSharp，因爲它的許可證。

感謝您的回覆。

編輯：我知道這是可能的。但我該怎麼做？

Answer 1

PDFSharp提供了從PDF中提取文本的所有工具。使用ContentReader類訪問每個頁面內的命令並從TJ/Tj運算符中提取字符串。

我已經上傳了一個簡單的實現github。

Answer 2

我已經以某種方式實現了它與David做的相似。 這裏是我的代碼：

{ 
     // .... 
     var page = document.Pages[1]; 
     CObject content = ContentReader.ReadContent(page); 
     var extractedText = ExtractText(content); 
     // ... 
    } 

    private IEnumerable<string> ExtractText(CObject cObject) 
    { 
     var textList = new List<string>(); 
     if (cObject is COperator) 
     { 
      var cOperator = cObject as COperator; 
      if (cOperator.OpCode.Name== OpCodeName.Tj.ToString() || 
       cOperator.OpCode.Name == OpCodeName.TJ.ToString()) 
      { 
       foreach (var cOperand in cOperator.Operands) 
       { 
        textList.AddRange(ExtractText(cOperand)); 
       } 
      } 
     } 
     else if (cObject is CSequence) 
     { 
      var cSequence = cObject as CSequence; 
      foreach (var element in cSequence) 
      { 
       textList.AddRange(ExtractText(element)); 
      } 
     } 
     else if (cObject is CString) 
     { 
      var cString = cObject as CString; 
      textList.Add(cString.Value); 
     } 
     return textList; 
    } 

Answer 3

拿了Sergio的答案，並取得了一定的擴展方法。我也將字符串的積累變成了一個迭代器。

public static class PdfSharpExtensions 
{ 
    public static IEnumerable<string> ExtractText(this PdfPage page) 
    {  
     var content = ContentReader.ReadContent(page);  
     var text = content.ExtractText(); 
     return text; 
    } 

    public static IEnumerable<string> ExtractText(this CObject cObject) 
    { 
     if (cObject is COperator) 
     { 
      var cOperator = cObject as COperator; 
      if (cOperator.OpCode.Name== OpCodeName.Tj.ToString() || 
       cOperator.OpCode.Name == OpCodeName.TJ.ToString()) 
      { 
       foreach (var cOperand in cOperator.Operands) 
        foreach (var txt in ExtractText(cOperand)) 
         yield return txt; 
      } 
     } 
     else if (cObject is CSequence) 
     { 
      var cSequence = cObject as CSequence; 
      foreach (var element in cSequence) 
       foreach (var txt in ExtractText(element)) 
        yield return txt; 
     } 
     else if (cObject is CString) 
     { 
      var cString = cObject as CString; 
      yield return cString.Value; 
     } 
    } 
}