如何从Program类访问Form1公共功能

Question

I'm trying to create a function that can be called from the "Program" class that could call the AppendText method of the textBoxes in my form. The goal at the end is to use this function as a replacement to the Console.WriteLine so I need to be able to pass a string to that function so it appends that specific bit of text.

My first instinct was to create a public method in my Form1 class that I could then call from the "Program". Here it is : In the Form1 class :

public void Add(String message)
        {
            textBox1.AppendText(message + Environment.NewLine);
        }

The weird thing is that when I call that method from the Form1 class, it works fine but when I call it from the Program class, nothing happens, even tho the method is public.

Calling the following doesn't do any thing and my form appears but the textbox is empty.

static void Main()
        {        
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Form1 mainForm = new Form1();
            Application.Run(mainForm);
            mainForm.Add("hello world");
        }

but adding that function to the constructor of Form1 works and the textBox appears with the text in

public Form1()
        {
            InitializeComponent();
            this.Add("hello");
        }

I'm confused as to why a function would behave differently from inside the class or outside when the code compile fine and doesn't throw any error.

Answer 1

When you call Application.Run, control enters in a loop, so, the next line only executes when the app exits

https://docs.microsoft.com/es-es/dotnet/api/system.windows.forms.application.run?view=netframework-4.7.2