Question

private void showCategory_Load(object sender, EventArgs e)
{
   string categoryId = "100"
}

private void button1_Click(object sender, EventArgs e)
{
   textBox1.Text = categoryId;
}

how to pass string categoryId from form load to button click?
Thank you.

Answer 1

If it’s Windows Forms application than using the variable on the class level, not in the function

public partial class showCategory : Form
{
    string categoryId = null;

    private void showCategory_Load(object sender, EventArgs e)
    {
        this.categoryId = "100";
    }

    private void button1_Click(object sender, EventArgs e)
    {
        textBox1.Text = this.categoryId;
    }
}

If it’s Web Application – store the value the some state callection: ViewState, Session, HiddenField and so on..