Question: I have two classes(Data\_Reader And Display\_Data) and a GUI\_Form.  

What i want is to Display the Read data of Data\_Reader Class on Textbox which exists on GUI\_Form so to wrap it i wrote Display\_Data class .  

But i got the folowing exception:

> 
> Cross-thread operation not valid: Control 'textBox1' accessed from a thread other than the thread it was created on
> 
> 
> 

Can anyone knows how to solve this ? 
I just Want to update Read Data values on GUI Form.

```
//    Gui Form
//    ============
public partial class GUI_Form: Form
{
}
//    ==============
//    Display Data Class
//    ===========
public static class Display_Data
{
    public delegate void MyDelegate(Label myControl, string myArg2);
    public static void DelegateMethod(Label myControl, string myCaption)
        {
            myControl.Text = myCaption;
        } 
}

//=========================
//  Reader Class
//=========================
public void Data_Reader
{
    string Data_Received_text="Test";
    private System.ComponentModel.ISynchronizeInvoke _syn;
    Meter_Data_Class.packets_received_counter_status_display++;
    //it will call the display_Data class delegate method to update textbox on gui
    syn.BeginInvoke(new
                  Display_Data.MyDelegate(Display_Data.DelegateMethod),Data_Received_text);

}

```

Answer: 
You can use the keyboard. Usually `m-.` or `esc-.` in Emacs. The cursor must be on the symbol.
The usual way is to create a TAGS file using etags:

```
$ find . -type f -iname "*.lisp*" | etags -

```

Then, do `M-x visit-tags-table` and navigate to the TAGS file. After the tags are loaded, you can simply do `M-.` with point on function and it will open in the current buffer.

Also, you can use `M-*` to go back to where you were before.

If you're using projectile, you can simply keep your TAGS file in the project root and you won't need to run `M-x visit-tags-table`. Projectile will load the tags table automatically when you first press `M-.`