Question

Note: Part of a series: C#: Accessing form members from another class and How to access form objects from another cs file in C#.

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Hello,

The Idea is to notify the user using the memo when a packet is received/sent in a TCP Client.

After couple of fixes,the most suitable solution seemed to be this one

    public string TextValue     {         set         {             this.Memo.Text += value + '\n';         }     } 

That’s how it’s being called

    var form = Form.ActiveForm as Form1;     if(form != null)         form.TextValue = 'Test asdasd'; 

However,calling the code throws an exception ,because of Unsafe thread call.I found a solution at msdn,but I can’t seem to acquire the method they’ve used there.

This is my remake,which doesn’t work.

    private void SetTextMemo(string txt)     {         if(this.Memo.InvokeRequired)         {             this.Invoke(SetTextMemo,txt); //error here         }         else         {             this.Memo.Text += txt + '\n';         }     } 

errors:

Argument ‘1’: cannot convert from ‘method group’ to ‘System.Delegate’

Argument ‘2’: cannot convert from ‘string’ to ‘object[]’

Basically,I’m trying to access the Memo(or more likely said,add text to the memo) from another thread using Invoke.I never used it before,maybe that’s why I misunderstand my mistake.

Answer 1

The easy way is:

this.Invoke((MethodInvoker)delegate {     this.Memo.Text += txt + '\n'; }); 

Which uses an anonymous method to do the job inline. Since you expect to be on another thread, you may as well just call Invoke – it is safe even from the UI thread.