c# - creating a new row in ListView and then writing to COM port delayed ListView loadtime, solution? -

the listview renders row item quite fast @ normal state. when call function write com port (pole display) . load time of list view increases , slows down whole process. i've first called function add item listview. list view uses addrange method add items. vfd function called open com port first , initialize port write port.

here full sample code:

//function add new row item in listview private void listfunction(int id)   {    listviewitem checkitem = listview1.finditemwithtext(getproduct(id));    if (checkitem != null)    {     //messagebox.show("it exist");     int itemvalue = int.parse(checkitem.subitems[2].text) + 1;     checkitem.subitems[2].text = itemvalue.tostring();                 int ttlamt = getprice(id) * int.parse(checkitem.subitems[2].text);                 string totalamount = ttlamt.tostring();                 checkitem.subitems[4].text = totalamount;    }    else    {                           // if doesnot exist                 int ttlamt = getprice(id);     listviewitem item1 = new listviewitem("1");     item1.subitems.add(getproduct(id));     item1.subitems.add("1");     item1.subitems.add(getprice(id).tostring());                 string totalamount = ttlamt.tostring();                 item1.subitems.add(totalamount);     listview1.items.addrange(new listviewitem[] { item1 });    }        // write port public void vfd(int id)   {    serialport vfd = new serialport("com5", 9600, parity.none, 8, stopbits.one);             vfd.open();    vfd.write(initialize);    vfd.write(getproduct(id) + ":" + getprice(id));    vfd.write("\x1b\x6c\x09\x02");    vfd.write("total: " + totalamt.text);       vfd.close();     }  private void button1_click(object sender, eventargs e)   {    int id = 10001; //add list    listfunction(id);      // vfd display     vfd(id);;   } 

all of items called database.

this slows down list render performance.

how rid of this?

you send data com port on separate thread 1 isn't held up, careful make code thread-safe.