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Cannot apply "Visible" method from a global class to multiple winforms in C#

I need your help with something I am dealing with. I am new to c# and I am creating a winforms application with multiple forms in it. There's a piece of code that needs to be present on all forms but since I don't want to just copy and paste it in every form, I created a class that stores that code and then I only want to call that class.
My global code that needs to be repeated is as follows,
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace Delfoi_Tourist_Guide
{
public class Login_User
{
public void CheckStatus()
{
DialogResult dialogResult = MessageBox.Show("Do your want to disconnect?;", "Disconnect", MessageBoxButtons.YesNo);
if (dialogResult == DialogResult.Yes)
{
Welcome form1 = new Welcome();
form1.Show();
this.Visible = false;
}
else if (dialogResult == DialogResult.No)
{
MessageBox.Show("Συνεχίστε την περιήγηση σας!!!");
}
}
}
}
I am also providing you a portion of code from another form in which I am applying my global code
private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
{
Login_User loginUser = new Login_User();
loginUser.CheckStatus();
}
My problem is that I can't transfer the "Visible" method from my global class to the other classes. I suppose this happens because my global class isn't attached to a winform. It's just a piece of code that's been used globally. What am I doing wrong???

try this
public static void CheckStatus(System.Windows.Form currentForm)
{
.....
currentForm.Visible = false;
`````
}
and call it
.....
Login_User.CheckStatus(this);
.....

Your problem occurs because the keyword "this" applies as property to the form, not the class. In your case you have to pass an instance of the form as parameter in your CheckStatus method. But since you want this to apply in all of your forms, you have to type the word "Form". Below I am providing you the answer,
Your Global Code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace Delfoi_Tourist_Guide
{
public static class Login_User
{
public static void CheckStatus(Form currentForm)
{
DialogResult dialogResult = MessageBox.Show("Do your want to disconnect?;", "Disconnect", MessageBoxButtons.YesNo);
if (dialogResult == DialogResult.Yes)
{
Welcome form1 = new Welcome();
form1.Show();
currentForm.Visible = false;
}
else if (dialogResult == DialogResult.No)
{
MessageBox.Show("Συνεχίστε την περιήγηση σας!!!");
}
}
}
}
and then you have to apply your global code to your desired forms, as follows.
Please note that you have to set the whole class as static in order for it, to work.
Apply Global Code To Forms
private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
{
Login_User.CheckStatus(this);
}

"ExportToDataGridView" Does not exist in .NET GemBox

Ive been trying to find why this happend but for some reason .net of gembox.spreadsheet.winformutilities wont provide ExportToDataGridView on the code:
using System.Windows.Forms;
using GemBox.Spreadsheet;
using GemBox.Spreadsheet.WinFormsUtilities;namespace Excel
{
public partial class UserControl1 : UserControl
{
private void bunifuFlatButton2_Click(object sender, EventArgs e)
{
OpenFileDialog open = new OpenFileDialog();
open.Filter = "Al files (*.*)|*.*|";
open.FilterIndex = 1;
if (open.ShowDialog()== DialogResult.OK)
{
ExcelFile ef = new ExcelFile();
ExcelWorksheet ws = ef.Worksheets.Add("Export");
DataGridViewConverter.***ExportToDataGridView***(ef.Worksheets.ActiveWorksheet, this.dataGridView1, new ExportToDataGridViewOptions() { ColumnHeaders = true });
}
}
}
}
thank you for your answer in advance!

The problem occurred because of the name collision:
namespace Excel
{
public partial class UserControl1 : UserControl
{
public static class DataGridViewConverter
{
}
}
}
So there are two classes of same name:
Excel.UserControl1.DataGridViewConverter
GemBox.Spreadsheet.WinFormsUtilities.DataGridViewConverter
The solution is to either use the class's full name, or you could define an alias name, for example:
// ...
using System.Windows.Forms;
using GemBox.Spreadsheet;
using GemBoxDataGridViewConverter = GemBox.Spreadsheet.WinFormsUtilities.DataGridViewConverter;
namespace Excel
{
public partial class UserControl1 : UserControl
{
private void bunifuFlatButton2_Click(object sender, EventArgs e)
{
GemBoxDataGridViewConverter.ExportToDataGridView(...);
}
}
}
Also as an FYI, you can download a working example from GitHub or check the Windows Forms online example.

Phone list c# (Reading from a file)

This is a pretty simple program. It IS a homework project. The program should start, read a .txt file, populate the name list and when you click on the name, the phone number is displayed. I have it coded, no errors, no warnings. It will not read the .txt file and I can't figure out why. I've been scouring my book, youtube, even here, but can't pin it down. Any help would be appreciated. Here is my current 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.IO;
namespace Phonebook
{
struct PhoneBookEntry
{
public string name;
public string phone;
}
public partial class Form1 : Form
{
// FIeld to hold a list of PhoneBookEntry objects.
private List<PhoneBookEntry> phoneList = new List<PhoneBookEntry>();
public Form1()
{
InitializeComponent();
}
// The ReadFile method reads the contents of the
//PhoneList.txt file and tores it as PhoneBokeEntry
// objects in the phoneList.
private void ReadFile()
{
try
{
StreamReader inputFile; // To read the file
string line; // To hold a line from the file
// Create an instance of the PhoneBookEntry structure.
PhoneBookEntry entry = new PhoneBookEntry();
// Create a delimiter array.
char[] delim = { ',' };
// Open the PhoneList file.
inputFile = File.OpenText("PhoneList.txt");
// Read the lines from the file.
while (!inputFile.EndOfStream)
{
// Read a line from the file.
line = inputFile.ReadLine();
// Tokenize the line
string[] tokens = line.Split(delim);
// Store the tokens in the entry object.
entry.name = tokens[0];
entry.phone = tokens[1];
// Add the entry object to the List.
phoneList.Add(entry);
}
}
catch (Exception ex)
{
// Display an error message.
MessageBox.Show(ex.Message);
}
}
// The DisplayNames method displays the list of names
// in the namesListBox conrol.
private void DisplayNames()
{
foreach (PhoneBookEntry entry in phoneList)
{
nameListBox.Items.Add(entry.name);
}
}
private void Form1_Load(object sender, EventArgs e)
{
// Read the PhoneList.txt file.
ReadFile();
// DIsplay the names.
DisplayNames();
}
private void nameListBox_SelectedIndexChanged(object sender, EventArgs e)
{
// Get the index of the selected item.
int index = nameListBox.SelectedIndex;
// Display the corresponding phone number.
phoneLabel.Text = phoneList[index].phone;
}
private void exitButton_Click(object sender, EventArgs e)
{
// close the form.
this.Close();
}
private void Form1_Load_1(object sender, EventArgs e)
{
}
}
}

Using OpenFileDialog and StreamReader

There are two classes, one to cover the form (class 1) and the other to cover what gets displayed on the form (class 2). I'm trying to call a method in class 1 from class 2 to display certain information in a text box. I keep getting the error:
An object reference is required for the non-static field, method, or property
I've encountered this error before and been able to make it through, but nothing I've attempted so far has helped in this instance. I'm posting code for both the classes.
Class 1:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Forms;
namespace Project6
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
Stream myStream = null;
//Create an instance of the open file dialog box
OpenFileDialog ofd = new OpenFileDialog();
//Set parameters, filter options, and filter index
ofd.InitialDirectory = "c:\\";
ofd.Filter = "Text Files (.txt)|*.txt";
ofd.FilterIndex = 2;
ofd.Multiselect = false;
if (ofd.ShowDialog() == DialogResult.OK)
{
try
{
if ((myStream = ofd.OpenFile()) != null)
{
using (myStream = ofd.OpenFile())
{
StreamReader reader = new StreamReader(myStream);
string studentInformation = "";
string[] studentInformationArray = new string[11];
studentInformation = reader.ReadLine();
while ((studentInformation = reader.ReadLine()) != null)
{
studentInformationArray = studentInformation.Split(',');
Student newStudent = new Student(studentInformationArray);
}
}
}
}
catch (Exception ex)
{
MessageBox.Show("Error: Could not read file from disk. Original error: " + ex.Message);
}
}
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
textBox1.Text = Student.GetName(); //This generates the compiler error
textBox1.Select(6, 5);
MessageBox.Show(textBox1.SelectedText);
}
}
}
Class 2:
using System;
using System.Windows.Forms;
namespace Project6
{
class Student
{
//Initialize variables
private string[] studentInformationArray;
//Constructor that accepts the studentInformationArray as an argument
public Student(string[] studentInformationArray)
{
this.studentInformationArray = studentInformationArray;
}
public Student()
{
string className = studentInformationArray[1];
string semester = studentInformationArray[2];
string picture = studentInformationArray[3];
int project1 = Convert.ToInt32(studentInformationArray[4]);
int project2 = Convert.ToInt32(studentInformationArray[5]);
int project3 = Convert.ToInt32(studentInformationArray[6]);
int project4 = Convert.ToInt32(studentInformationArray[7]);
int project5 = Convert.ToInt32(studentInformationArray[8]);
int project6 = Convert.ToInt32(studentInformationArray[9]);
int midtermExam = Convert.ToInt32(studentInformationArray[10]);
int finalExam = Convert.ToInt32(studentInformationArray[11]);
}
public string GetName()
{
string studentName;
studentName = studentInformationArray[0];
return studentName;
}
}
}

That's because that's not how you use the OpenFileDialog. Take a look at this example hosted by the MSDN here:
Edit: answering to your edited question. You will always get a NullReferenceException in the Student() constructor because you are never assigning something to your studentInformationArray. So you can fix it like this:
public Student()
{
studentInformationArray = new studentInformationArray[12];
string className = studentInformationArray[1];
// rest of your code...
}
However, you should take into account that studentInformationArray will be an empty array unless you assign something to it. Since you have a Student() overload that takes a string[], I'd suggest you that you either remove the default constructor or make it call the overloaded with default information, like this:
public Student(string[] studentInformationArray)
{
string className = studentInformationArray[1];
// rest of your code...
int project1 = int.Parse(studentInformationArray[4]); // always prefer int.Parse() instead of Convert.ToInt32()
// rest of your code...
this.studentInformationArray = studentInformationArray;
}
public Student()
{
string[] defaultInformation = new string[12];
// add information
defaultInformation[0] = "some information";
// ...
new Student(defaultInformation);
}
Some more points to take into account:
Class-level fields/properties should be spelled in Pascal Case (first letter of each word in uppercase, rest in lowercase)
Try to never use this.variableName = variableName.
Variables names should never include the type of the variable, that's redundant.
So, for example, change this:
private string[] studentInformationArray;
for this:
private string[] StudentInformation;
Answering your last question, regarding the compiler error, you need a reference to the Student read in order to get its name. You could do something like this:
public partial class Form1 : Form
{
private Student StudentRead;
// rest of your code...
// from your read method:
StudentRead = new Student(studentInformationArray);
// and finally:
private void textBox1_TextChanged(object sender, EventArgs e)
{
textBox1.Text = StudentRead.GetName();

Using CodeDOM to source code and class file togther

i have created a form for a codeDOM compiler and it can compile my code if its in a single text file but i want to be able to compile the source code in the text file and a class thats in a text file so they can work together.
I am unsure how to code codeDOM to add my class file as a resource for the main source to be compiled
Heres what i have so far
codeDOM Compiler
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.CodeDom.Compiler;
using Microsoft.CSharp;
namespace CodeDOMSourceTest
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void btnCompile_Click(object sender, EventArgs e)
{
CompilerParameters Params = new CompilerParameters();
Params.GenerateExecutable = true;
Params.ReferencedAssemblies.Add("System.dll");
Params.ReferencedAssemblies.Add("TextFile1.txt");
Params.OutputAssembly = "output.exe";
string Source = Properties.Resources.CodeDOMSource;
Source = Source.Replace("[TEXT]", txtReplace.Text);
CompilerResults Results = new CSharpCodeProvider().CompileAssemblyFromSource(Params, Source);
if (Results.Errors.Count > 0)
{
foreach (CompilerError err in Results.Errors)
Console.WriteLine(err.ToString());
}
else Console.WriteLine("Compiled just fine!");
}
}
}
Source file
namespace testingCodeDOM
{
class Program
{
static void Main()
{
System.Console.WriteLine("[TEXT]");
Console.WriteLine(Testing.textwork());
System.Console.Read();
}
}
}
ClassFile
namespace testingCodeDOM
{
class Testing
{
public static string textwork()
{
string hello = "calss worked";
return hello;
}enter code here
}
}
Any ideas how to do this because i have googled it an am getting no were or at least nothing i understand
on a side not this works with with just the source but am trying to adapt it to use class files aswell

The CompileAssemblyFromSource() method can take any number of source code strings (since it's a params method). So, you can call it something like:
CompileAssemblyFromSource(Params, Source, ClassFile)
Where ClassFile is a string that contains the text of the second file.