从另一个静态类更改文本字段的文本

Question

Here is my code.

Main class

namespace winapp
{
public partial class Main_Form : Form
{

    //Here is textfield1

    public Main_Form()
    {
       InitializeComponent();
    }
 }

the other class

namespace winapp
{
public partial class second: Form
{
   static Main_Form main_form = new Main_Form();
   string sss = "12345";

    public second()
    {
        InitializeComponent();
    }

    private void but_Click(object sender, EventArgs e)
    {
       //I want to change the text from here
        main_form.textbox1.text = this.sss;
    }    

Like above, I want to change the text of a textField in the main class with second class.
But my the text of textfiled does not change.

Regurd if anyone can help me.

Answer 1

The issue is that you're creating a brand new Main_Form . Instead you can pass your instance of Main_Form to second :

public partial class Second : Form
{
    private readonly Main_Form _mainForm;

    public Second(Main_Form mainForm) {
        _mainForm = mainForm;
    }
}

I would then create a property on MainForm to access the textbox:

public ... Main_Form : Form
{
    public string MyText {
        get { return textbox1.Text; }
        set { textbox1.Text = value; }
    }
}

I'm not sure where you create your second form but it would now look like this as long as you're creating it in Main_Form :

Second secondForm = new Second(this);

And then second can access Main_Form's MyText property which will set the textbox.