What is "CS0642 Possible mistaken empty statement"

Question

Dear All,

using System.IO;
using System.Runtime.InteropServices;
using System.Text;

namespace NewTims
{ 
    public class IniFile
    {
        public string path;

        [DllImport("kernel32")]
        private static extern long WritePrivateProfileString(string section, string key, string val, string filePath);

        [DllImport("kernel32")]
        private static extern int GetPrivateProfileString(string section,
            string key, string def, StringBuilder retVal,
            int size, string filePath);

        public IniFile(string INIPath)
        {
            path = INIPath;
        }

        public void IniWriteValue(string Section, string Key, string Value)
        {
            if (!File.Exists(Directory.GetCurrentDirectory()+this.path));
            {
                File.Create(this.path);
            }
            WritePrivateProfileString(Section, Key, Value, this.path);
        }


        public string IniReadValue(string Section, string Key)
        {
            StringBuilder temp = new StringBuilder(255);
            GetPrivateProfileString(Section, Key, "", temp, 255, this.path);
            return temp.ToString();
        }
    }
}

I want to write a utility that can be called by the syntax as follows.

IniFile("NewTims");
IniWriteValue("History", "Prior Color");

I encounter an issue as follows. The "path" property should be on the type static.

1. However, changing the word from "public" to "static", all the "this.path" are red-lined. Are properties can't be static? Could anybody help me modify the code?
2. The line "if (!File.Exists(Directory.GetCurrentDirectoy()+this.path))" is marked "CS0642 Possible mistaken empty statement". Could anybody explain why?

Answer 1

Hi @BenTam ,

The issue is with the semicolon at the end of the if statement, this semicolon terminates the if statement, making the subsequent block always execute, regardless of the condition. As a result, File.Create(this.path); will be executed every time, even if the file already exists.

Check Compiler Warning (level 3) CS0642.

Best Regards.

Jiachen Li

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Answer 2

The “this” is used to access instance properties of the current instance from a class instance method. Static properties belong to a class not a class instance, so it <classname>.prop

if if not ambiguous, when referenced from a class method, the prefix is optional.