c＃在文本文件中搜索特定字符串并获取文件路径

Question

Using c# in a Windows Form I need to search a directory "C:\\XML\\Outbound" for the file that contains an order number 3860457 and return the path to the file that contains the order number so I can then open the file and display the contents to the user in a RickTextBox.

The end user will have the order number but will not know what file contains that order number so that is why I need to search all files till it finds the filecontaining the order number and return the path (eg "C:\\XML\\Outbound\\some_file_name_123.txt" )

I am somewhat new to c# so I am not even sure where to start with this. Any direction for this?

Sorry the order number is inside the file so I need to search each file contents for the order number and once the file containing the order number is found return the path to that file. Order number is not part of the file name.

Answer 1

Straight answer:

public string GetFileName(string search){ 
    List<string> paths = Directory.GetFiles(@"C:\XML\Outbond","*.txt",SearchOption.AllDirectories).ToList();
    string path = paths.FirstOrDefault(p=>File.ReadAllLines(p).Any(line=>line.IndexOf(search)>=0));
    return path;    
}

Not-so straight answer:

Even though the above function will give you the path for given string (some handling of errors and edge cases may be nice) it will be terribly slow, especially if you have lots of files. If that's the case you need to tell us more about your environment because chances are you're doing it wrong (: