系统线程：跨线程操作无效

Question

The error I'm having from my thread is:

Cross-thread operation not valid. Control 'richTextBox8' accessed from a thread other than the thread it was created on.

I have this code I use for my List of string that is causing the error.

string[] parts = richTextBox8.Text.Split(new string[] { " " }, StringSplitOptions.RemoveEmptyEntries);

Now I'm working with using System.Threading that requires to transform the code above into a format something like this code to work but I'm unable to do it or is there some other way?

richTextBox8.Invoke((Action)(() => richTextBox8.Text += "http://elibrary.judiciary.gov.ph/" + str + "\n"));

Answer 1

your string array (string[]) looks fine to me. If there are whitespaces inisde richTextBox8 it should do the splitting.

Regarding your Threading, try with a use of delegate, like:

    public delegate void MyDelegate(string message);

   //when you have to use Invoke method, call this one:
   private void UpdatingRTB(string str)
   {
       if(richTextBox8.InvokeRequired)
           richTextBox8.Invoke(new MyDelegate(UpdatingRTB), new object []{ msg });
       else
           richTextBox8.AppendText(msg);
   }

Answer 2

string[] parts = null;
richTextBox8.Invoke((Action)(() => 
    {
        parts = richTextBox8.Text.Split(new string[] { " " },
        StringSplitOptions.RemoveEmptyEntries); //added semicolon
    }));

Answer 3

You only need the text extraction done on the UI thread.

With variable capturing :

string text = null;
richTextBox8.Invoke((Action)(() => text = richTextBox8.Text));
string[] parts = text.Split(new string[] { " " }, StringSplitOptions.RemoveEmptyEntries);

Without variable capturing (slightly more efficient):

var ret = (string)richTextBox8.Invoke((Func<string>)(() => richTextBox8.Text));
parts = ret.Split(new string[] { " " }, StringSplitOptions.RemoveEmptyEntries);