Closing main from the child form in winforms app

I have a form A with a button called 开发者_如何转开发btnA and a datagrid. When I click on this button, another form B opens which has a button btnB. When I click on btnB, I need to close form B and refresh form A. How do I achieve this?

Thanks.

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When you create FormB, pass a reference to FormA

class FormB : Form
{
    FormB(FormA parent)
    { 
        this.Parent = parent;
    }
    ...

    protected void btnB_Click(object sender, EventArgs e)
    {
       parent.RefreshGrid();
       this.Close();
    }
}

and then on butB click, you can close formB and access formA to refresh it.

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You can use ShowDialog() in FormA to show FormB. This will show FormB modally. Then, when you close FormB, execution will continue in FormA on the statement after ShowDialog(). Write your refresh code there.