无效的操作异常线程

Question

tpide1=new Thread(new ThreadStart(pide1));
        tjunta=new Thread(new ThreadStart(junta));
public void pide1() 
    {
        while (cuadroactual1 < cuadrofinal) 
        {
            if (cuadroactual3 == cuadroactual1 )
            {
                lector.lee1(cuadroactual1);
                cuadroactual1++;
                reproductorlisto1.Set();
            }
        }
    }


    public void junta() 
    {

        while (cuadroactual3 < cuadrofinal)
        {
            AutoResetEvent.WaitAll(estanlistos);

                lector.junta(cuadroactual3);
                canvasjuntar.Dispatcher.Invoke((Action)(() => {  canvasjuntar.Background = new ImageBrush(lector.BMS); }));
                cuadroactual3++;
            }

    }

when i execute the program it throws an InvalidOperationException ("The calling thread cannot access this object because a different thread owns it") this happen in different lines everytime I run the program and do not let me see where the mistake is ("No source available").(The exception always appear when I am debuggin inside of the method "junta()" but not always in the same line) Please help me!

Answer 1

Since you did not specify I'm assuming you use wpf.

You can only access DependencyProperties from the main UI thread. What is probably happening is that on or more of your variables cuadroactual1 , cuadroactual3 , cuadrofinal , lector or reproductorlisto1 were declared as DependencyProperties and the exception is thrown when one of the threads tries to access them.