C#中的字符串操作

Question

我有一个在文本文件中查找单词并将其打印出来的程序。但这是一个学校作业，我需要使用一定程度的面向对象编程，比如使用不同的类和接口。

所以，我的问题是，我有两个公共类，当在主类中调用和采用时，使用main方法，打印出我想要的两个字符串值。

代码如下所示

public class GetFilePath
{
    public string FilePath;

    public GetFilePath(string fn)
    {
        /// string path = "testfile.txt";
        FilePath = fn;
    }
    public void SetFilename(string NewFilePath)
    {
        FilePath = NewFilePath;
    }   
}

public class GetSearchWord
{

    public string WordSearch;
    public GetSearchWord(string st)
    {
        WordSearch = st;
    }


    public void SetSearchTerm(string NewSearchTerm)
    {
        WordSearch = NewSearchTerm;
    }
}

这些实现到main函数中，如下所示

        Console.Write("please enter a file to search for: ");
        // Call the constructor that has no parameters.
        GetFilePath Filepath1 = new GetFilePath("");
        Console.WriteLine(Filepath1.FilePath);
        Filepath1.SetFilename("testfile.txt");
        Console.WriteLine(Filepath1.FilePath);

        // Call the constructor that has one parameter.
        Console.Write("please enter a word to search for in the file: ");
        GetSearchWord SearchedWord1 = new GetSearchWord("");
        Console.WriteLine(SearchedWord1.WordSearch);
        SearchedWord1.SetSearchTerm("true");
        Console.WriteLine(SearchedWord1.WordSearch);

但是我需要将Filepath1.FilePath和SearchedWord1.WordSearch连接到以下字符串

string FilePath = "";
string WordSearch = "";

正如你所看到的，目前这些都是空的。

它们是我的搜索函数中的关键字符串，它实际上是搜索包含单词的行！

FilePath和WordSearched字符串的用法如下

using (StreamReader fs = File.OpenText(FilePath))
        {
            int count = 0; //counts the number of times wordResponse is found.
            int lineNumber = 0;
            while (!fs.EndOfStream)
            {
                string line = fs.ReadLine();
                lineNumber++;
                int position = line.IndexOf(WordSearch);
                if (position != -1)
                {
                    count++;
                    Console.WriteLine("Match#{0} line {1}: {2}", count, lineNumber, line);
                }
            }

            if (count == 0)
            {
                Console.WriteLine("your word was not found!");
            }
            else
            {
                Console.WriteLine("Your word was found " + count + " times!");
            }
            Console.WriteLine("Press enter to quit.");
            Console.ReadKey();
        }

我尝试做的是设置

string WordSearch = SearchedWord1.WordSearch;

例如，SearchedWord1.WordSearch当前设置为"true“，这是我想要搜索文件的关键字。