C#

while(myFormIsVisible)
{
   Thread.Sleep(0);
}

Judah Himango wrote:

First, you cannot start a form from another thread.

private void fileProccessing_Click(object obj, EventArgs ea)
{
       fP = new Thread(new ThreadStart(fProc));
       fP.Start();
}

public void fProc()
{      
       editForm edtFrm = new editForm(); // this Form I want to show
       ...someText...
       if( ... )
       {
            edtFrm.Show(); // so I try to show the form
            edtFrm.cmbBox.DataSource = fieldsBaseD; // bind array to comboBox in this editForm
            
            while (edtFrm.Visible == true)
            {
                Thread.Sleep(0);
            }
       }

}

class editForm : Form
{
    public ComboBox cmbBox;
    private Button buttonOk;
    public Label label1;

    public editForm()
    {
        InitializeComponent();
    }
    
    .... // InitializeComponent function
}