Open associated files with C# program

• Download associateCsharp.zip - 1 MB

Introduction

Almost all of the basic functions of the program(browser, text editor, image editor, media player) that you can associate files with it and open it. I want a simple and effective method to show the arguments (associated files) to open. How to associate files with C# program? I present the step by step procedure below.

1. Step-Create the general form

Create a new Windows Forms application in Visual Studio. Add menustrip(optional), toolstrip(optional), statusstrip(optional), and richtextbox controls to general form.

It should look like:

2. Step-Write the code

Illustrating the operation of the program:

The Program.cs is as follows

[STAThread] 
        static void Main(string[] args) 
        { 
        }

To be transformed into the main library to be able to recive arguments.

This part of the program will determine whether there is an argument: If the argument is not equal to zero and greater than zero, then there is an argument. generating a string variable that contains the argument. if a user opens a file in the program, it will be stored in the variable the path. then verify that the file exists. If no argument is specified, the program "normally" runs.

/// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main(string[] args)
        {
            //with args(user open file with the program)
            if (args != null && args.Length > 0)
            {
                string fileName = args[0];
                //Check file exists
                if(File.Exists(fileName))
                {
                    
                }
                
            }
                //without args
            else
            {
                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);
                Application.Run(new Form1());
            }
        }

Return to the Form1.cs file, make a public method that will open the associated file.

public void OpenFile(string filePath)
        {
 
    openStatus.Text = "Open file: " + filePath;
          Thread.Sleep(1000);
 
            string file = File.ReadAllText(filePath);
            richTextBox1.Text = file;
            openStatus.Text = "Ready";
        }

Now let us return to the Program.cs source file again. Create a new Form1, but it'll show you invite before the Open method, which read and displays the argument in the richtextbox.

The program has only one error: If the associated file does not exist does nothing. should be presented to the user with a message box that informs.

The Program.cs is as follows:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
 
namespace Associate
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main(string[] args)
        {
            //with args(user open file with the program)
            if (args != null && args.Length > 0)
            {
                string fileName = args[0];
                //Check file exists
                if(File.Exists(fileName))
                {
                    Application.EnableVisualStyles();
                    Application.SetCompatibleTextRenderingDefault(false);
 
                    Form1 MainFrom = new Form1();
                    MainFrom.OpenFile(fileName);
                    Application.Run(MainFrom);
                }
                //The file does not exist
                else
                {
                    MessageBox.Show("The file does not exist!", "Error!", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    Application.EnableVisualStyles();
                    Application.SetCompatibleTextRenderingDefault(false);
                    Application.Run(new Form1());
                }
            }
                //without args
            else
            {
                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);
                Application.Run(new Form1());
            }
        }
    }
}

Argument transfer splash screen via

Illustrating the operation of the program

Create splash screen form(download Office 2013 style splash screen: http://www.codeproject.com/Articles/804316/Office-Style-Splash-Screen) or use another one.

The splash screen source code, we create a public string variable, which will contain the path to the opened file.

//file path
        public string path = null;

Program.cs change the value of the variable in the argument.

//Check file exists
                if (File.Exists(fileName))
                {
                    Application.EnableVisualStyles();
                    Application.SetCompatibleTextRenderingDefault(false);
 
                    Splash splash = new Splash();
                    splash.path = fileName;
                    Application.Run(splash);
                }

If the variable is not null, then invite the Open method.

The splash screen with full source code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Threading.Tasks;
using System.Threading;
using Associate;
 
namespace Associate_with_splash_screen
{
    public partial class Splash : Form
    {
        //file path
        public string path = null;
 
 
        public Splash()
        {
            InitializeComponent();
 
            //Tasks
            //Starting
            tasks.Text = "Starting...";
            Thread.Sleep(1000);
 
 
 
            //start timer
            splashtime.Start();
        }
 
        public bool Isminimized = false;
 
        //Close Application
        private void close_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
        //Minimize Application
        private void minimize_Click(object sender, EventArgs e)
        {
            this.WindowState = FormWindowState.Minimized;
            Isminimized = true;
        }
        //Mouse hover and leave effects
        private void close_MouseHover(object sender, EventArgs e)
        {
            close.ForeColor = Color.Silver;
        }
 
        private void close_MouseLeave(object sender, EventArgs e)
        {
            close.ForeColor = Color.White;
        }
 
        private void minimize_MouseHover(object sender, EventArgs e)
        {
            minimize.ForeColor = Color.Silver;
        }
 
        private void minimize_MouseLeave(object sender, EventArgs e)
        {
            minimize.ForeColor = Color.White;
        }
 
        //Show MainForm(Form1)
        public void frmNewFormThread()
        {
 
            var frmNewForm = new Form1();
            if (Isminimized == true)
            {
                frmNewForm.WindowState = FormWindowState.Minimized;
            }
            else
            {
                frmNewForm.WindowState = FormWindowState.Maximized;
            }
 
            if(path != null)
            {
                frmNewForm.OpenFile(path);
            }
            Application.Run(frmNewForm);
        }
 
        private void splashtime_Tick(object sender, EventArgs e)
        {
            splashtime.Stop();
 
            var newThread = new System.Threading.Thread(frmNewFormThread);
            newThread.SetApartmentState(System.Threading.ApartmentState.STA);
            newThread.Start();
            this.Close();
        }
 
        private void Splash_FormClosed(object sender, FormClosedEventArgs e)
        {
 
        }
 
 
        private void Splash_MouseMove(object sender, MouseEventArgs e)
        {
 
        }
 
        private void Splash_MouseDown(object sender, MouseEventArgs e)
        {
 
        }
    }
}

3. Step-Checking the program:

Associate files, then open with program.

Give him an argument invalid file, let's look to react. Start cmd.exe, and start the example program with argument.

Example:

Command: start program.exe argument

Command: start iexplore.exe http://www.microsoft.com/

The latter command open the microsoft.com in the Internet Explorer browser(now the argument is the microsoft.com website).

Non-existent file is specified as an argument, so the program warns.