C# 使用word互操作提取word内容会导致错误

我正在尝试使用以下代码提取word内容：

// Open a doc file.
            Application application = new Application();
            Document document = application.Documents.Open("d:\\a.doc");

            // Loop through all words in the document.
            int count = document.Words.Count;
            for (int i = 1; i <= count; i++)
            {
                // Write the word.
                string text = document.Words[i].Text;
                Console.WriteLine("Word {0} = {1}", i, text);
            }
            // Close word.
            application.Quit();

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我已经安装了office 2013

我终于下载了aspire.docnuget，并使用它提取word文件的内容，如您所见：

   Document document = new Document();
            document.LoadFromFile(@"d:\a.docx");

            //Initialzie StringBuilder Instance
            StringBuilder sb = new StringBuilder();

            //Extract Text from Word and Save to StringBuilder Instance
            foreach (Section section in document.Sections)
            {
                foreach (Paragraph paragraph in section.Paragraphs)
                {
                    sb.AppendLine(paragraph.Text);
                }
            }

            //Create a New TXT File to Save Extracted Text
            Console.WriteLine(sb.ToString());
            Console.ReadLine();

---

但是在运行之后，我在哪一行得到这个错误？@MattBurland Document=application.Documents.Open（“d:\\a.doc”）；尝试

var application=新单词。_application（）和
var document=application.Documents.Open（@“D:\a.doc”）也许我搞错了，试试
var-application=new-Word.application（）。我不记得您是否需要下划线。@Equalsk无法解析Word.application！！！
   Document document = new Document();
            document.LoadFromFile(@"d:\a.docx");

            //Initialzie StringBuilder Instance
            StringBuilder sb = new StringBuilder();

            //Extract Text from Word and Save to StringBuilder Instance
            foreach (Section section in document.Sections)
            {
                foreach (Paragraph paragraph in section.Paragraphs)
                {
                    sb.AppendLine(paragraph.Text);
                }
            }

            //Create a New TXT File to Save Extracted Text
            Console.WriteLine(sb.ToString());
            Console.ReadLine();