c# - update wpf datagrid cell from other thread -

i'm trying implement simple spreadsheet using wpf datagrid. when users input formula in cell, engine calculates formula , update cell calculated value. of calculations handle take long time, want calculate in other threads.

i tried implement using celleditending event below. (the itemssource of datagrid1 bound datatable dtab.)

private void datagrid1_celleditending(object sender, datagridcelleditendingeventargs e) {     action calc = () => {         int r = datagrid1.items.indexof(e.row.item);         int c = datagrid1.columns.indexof(e.column);         dtab.rows[r].setfield(c, "x"); // calculated value     };                 action update = () => {         if (datagrid1.dispatcher.checkaccess()) calc();         else datagrid1.dispatcher.begininvoke(calc);     };      //update(); // run same ui thread     task.factory.startnew(update); // run different thread } 

when update cell value same ui thread, cell updated value "x", different thread, not. how can update cell value "x" different thread?

edit: code not throw invalidoperationexception bcz used dispatcher.begininvoke(). problem seems user input value (formula) overwrites calculated value want display.

you cannot update gui thread. fortunately .net provides mechanism handle this:

uicontrol.**dispatcher**.invoke(delegate) 

for example

datagrid1.dispatcher.invoke(() => myupdatefunction(datagrid1, data)) 

edit: sorry original code windows.forms