Use a control from a class function

Can someone give me a simple but working exemple of the method to use a control from a external class function ?

I mean by exemple, I have a textbox on my form and a button, bwhen I click the button it call a function from another class and that function change de textbox.text.

Thanks in advance.

You can a property of type TextBox that returns the instance of your TextBox or make this public and pass a reference of the instance of your Form or TextBox (anyway you want). Something like this.

VB Code:

private void Form1_Load(object sender, System.EventArgs e)
        {
            new Class1(this).ChangeTextBoxTextTo("Some text");
        }
 
        public TextBox MyTextBox
        {
            get{ return textBox1;}
            set{ textBox1=value;}
        }

and Class1 is something like this

VB Code:

using System;
using System.Windows.Forms;
namespace test
{
    /// <summary>
    /// Summary description for Class1.
    /// </summary>
    public class Class1
    {
        public Class1()
        {
            //
            // TODO: Add constructor logic here
            //
        }
        Form1 caller;
        public Class1(Form1 caller)
        {
            this.caller=caller;
        }
        public void ChangeTextBoxTextTo(string text)
        {
            caller.MyTextBox.Text=text;
        }
    }
}

Or there is an alternative making your TextBox a static which is not a member of the instance of your Form1 but as said (not a member of the instance of the Form), you can see it on the designer mode of your IDE. If you're interested, it's like this

VB Code:

public static TextBox txt=new TextBox();
        private void Form1_Load(object sender, System.EventArgs e)
        {
            this.Controls.Add(txt);
            new Class1().ChangeTextBoxTextTo("Some text");
        }

and the Class1 is something like

VB Code:

using System;
using System.Windows.Forms;
namespace test
{
    /// <summary>
    /// Summary description for Class1.
    /// </summary>
    public class Class1
    {
        public Class1()
        {
            //
            // TODO: Add constructor logic here
            //
        }
        public void ChangeTextBoxTextTo(string text)
        {
            Form1.txt.Text=text;
        }
    }
}

Is this what you want, or I am missing something?

Thanks you, it's working ;)