Loading settings from an ini/xml file

Question

How do I load a setting from an external xml file located in the same folder as my program? Or should I be using an old school .ini file? It is only the MySQL server name and a location name that I need to pass to my App.

Answer 1

You should look at Application Settings and the ConfigurationManager. You could also use the Connection Strings section in the app.config.

• How to: Add Application Configuration Files to C# Projects
• MySQL Connection Strings

... For AppSettings ...

C# Code... You will need reference System.Configuration

var value = ConfigurationManager.AppSettings["MySetting"];

App.Config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <appSettings>
    <add key="MySetting" value="My Value"/>
  </appSettings>
</configuration>

... For Connection Strings ...

C# Code... You will need reference System.Configuration

var value = ConfigurationManager.ConnectionStrings["MySqlConn"];

App.Config

<configuration>
  <connectionStrings>
    <add name ="MySqlConn"
         connectionString="Server=myServerAddress;Database=myDataBase;
                           Uid=myUsername;Pwd=myPassword;"/>
  </connectionStrings>
</configuration>

Answer 2

You might want to go with the new, but in case you want to go with the INI, here's some source for a windows forms version:

using Microsoft.VisualBasic;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.Runtime.InteropServices;
//After you've added this class code to your application, here's how you may want to use it:

//Dim objclsINI As New clsINI("c:\fName.ini")
//objclsINI.WriteINI("Settings", "ClockTime", "12:59")
//objclsINI.WriteINI("Settings", "ClockTime", "12:59", "c:\test.ini")
//Dim strData As String = objclsINI.ReadINI("Settings", "ClockTime", "(none)")

public class clsINI
{
    [DllImport("kernel32.dll", EntryPoint = "GetPrivateProfileStringA", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
    private static extern int GetPrivateProfileString(string lpApplicationName, string lpKeyName, string lpDefault, System.Text.StringBuilder lpReturnedString, int nSize, string lpFileName);
    [DllImport("kernel32.dll", EntryPoint = "WritePrivateProfileStringA", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
    private static extern int WritePrivateProfileString(string lpApplicationName, string lpKeyName, string lpString, string lpFileName);
    [DllImport("kernel32.dll", EntryPoint = "WritePrivateProfileStringA", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
    private static extern int FlushPrivateProfileString(int lpApplicationName, int lpKeyName, int lpString, string lpFileName);
    // API functions



    string strFilename;
    string strSection;

    string strKey;
    // Constructor, accepting a filename
    public clsINI(string Filename)
    {
        strFilename = Filename;
    }
    // Overloaded Constructor Creating The Default FileName
    public clsINI()
    {
        strFilename = Application.StartupPath + "\\" + Application.ProductName + ".ini";
    }

    // filename property
    public string FileName {
        get { return strFilename; }
        set { strFilename = value; }
    }
    // Section property
    public string Section {
        get { return strSection; }
        set { strSection = value; }
    }
    // Key property
    public string Key {
        get { return strKey; }
        set { strKey = value; }
    }

    public string ReadINI(string Default)
    {
        string functionReturnValue = null;
        // Returns a string from your INI file
        int intCharCount = 0;
        string strMessage = null;
        System.Text.StringBuilder objResult = new System.Text.StringBuilder(256);
        strMessage = "";
        if (string.IsNullOrEmpty(strKey))
            strMessage = "The INI File Class Does Not Have A Defined Key To Read.";
        if (string.IsNullOrEmpty(strSection))
            strMessage = strMessage + ControlChars.CrLf + "The INI File Class Does Not Have A Defined Section To Read.";
        if (!string.IsNullOrEmpty(strMessage)) {
            MessageBox.Show(strMessage, "INI Error");
            return;
        }
        intCharCount = GetPrivateProfileString(strSection, strKey, Default, objResult, objResult.Capacity, strFilename);
        if (intCharCount > 0)
            functionReturnValue = Strings.Left(objResult.ToString(), intCharCount);
        return functionReturnValue;
    }

    public string ReadINI(string Key, string Default)
    {
        string functionReturnValue = null;
        // Returns a string from your INI file
        int intCharCount = 0;
        System.Text.StringBuilder objResult = new System.Text.StringBuilder(256);
        if (string.IsNullOrEmpty(strSection)) {
            MessageBox.Show("The INI File Class Does Not Have A Defined Section.", "INI Error");
            return;
        }
        strKey = Key;
        intCharCount = GetPrivateProfileString(strSection, Key, Default, objResult, objResult.Capacity, strFilename);
        if (intCharCount > 0)
            functionReturnValue = Strings.Left(objResult.ToString(), intCharCount);
        return functionReturnValue;
    }

    public string ReadINI(string Section, string Key, string Default)
    {
        string functionReturnValue = null;
        // Returns a string from your INI file
        int intCharCount = 0;
        System.Text.StringBuilder objResult = new System.Text.StringBuilder(256);
        strSection = Section;
        strKey = Key;
        intCharCount = GetPrivateProfileString(Section, Key, Default, objResult, objResult.Capacity, strFilename);
        if (intCharCount > 0)
            functionReturnValue = Strings.Left(objResult.ToString(), intCharCount);
        return functionReturnValue;
    }

    public string ReadINI(string Section, string Key, string Default, string sFileName)
    {
        string functionReturnValue = null;
        // Returns a string from your INI file
        int intCharCount = 0;
        System.Text.StringBuilder objResult = new System.Text.StringBuilder(256);
        strKey = Key;
        strSection = Section;
        strFilename = sFileName;
        intCharCount = GetPrivateProfileString(Section, Key, Default, objResult, objResult.Capacity, sFileName);
        if (intCharCount > 0)
            functionReturnValue = Strings.Left(objResult.ToString(), intCharCount);
        return functionReturnValue;
    }

    public void WriteINI(string Value)
    {
        // Writes a string to your INI file
        string strMessage = null;
        strMessage = "";
        if (string.IsNullOrEmpty(strKey))
            strMessage = "The INI File Class Does Not Have A Defined Key To Write.";
        if (string.IsNullOrEmpty(strSection))
            strMessage = strMessage + ControlChars.CrLf + "The INI File Class Does Not Have A Defined Section To Write.";
        if (!string.IsNullOrEmpty(strMessage)) {
            MessageBox.Show(strMessage, "INI Error");
            return;
        }
        WritePrivateProfileString(strSection, strKey, Value, strFilename);
        Flush();
    }

    public void WriteINI(string Key, string Value)
    {
        // Writes a string to your INI file
        if (string.IsNullOrEmpty(strSection)) {
            MessageBox.Show("The INI File Class Does Not Have A Defined Section To Write.", "INI Error");
            return;
        }
        WritePrivateProfileString(strSection, Key, Value, strFilename);
        Flush();
    }

    public void WriteINI(string Section, string Key, string Value)
    {
        // Writes a string to your INI file
        strKey = Key;
        strSection = Section;
        WritePrivateProfileString(Section, Key, Value, strFilename);
        Flush();
    }

    public void WriteINI(string Section, string Key, string Value, string sFileName)
    {
        strKey = Key;
        strSection = Section;
        strFilename = sFileName;
        // Writes a string to your INI file
        WritePrivateProfileString(Section, Key, Value, sFileName);
        Flush();
    }

    private void Flush()
    {
        // Stores all the cached changes to your INI file
        FlushPrivateProfileString(0, 0, 0, strFilename);
    }

}

Answer 3

To Elaborate on Matthew W's answer, it sounds like you need to Add -> New Item -> Application Configuration File in your project. This will generate an app.config (which will compile to [executableName].exe.config).

Within the app.config, you'll have an area for ConnectionStrings. Put your connection information there and call it using ConfigurationManager.

Answer 4

.NET has the notion of a settings file associated with an assembly.

If your assembly name is:

My.Program.exe

you can create a settings file for that assembly that is automatically available through the ConfigurationManager:

My.Program.exe.config

You can easily make this a part of your project by adding an App.config file: http://msdn.microsoft.com/en-us/library/ms184658(VS.80).aspx