Question

I am trying to post text from a class into an active form and I am having a little trouble figuring out how to do it. I have seen a bunch about using Invoking to post things across threads/forms but I can’t get my class to see any public functions in the activeform.

Example

// File: Form1.cs

namespace Form1
{
    public partial class Form1 : Form
    {
        public void SetText(string text)
        {
            this.Invoke((MethodInvoker) delegate { \\ Always requires invoke
                TextBox1.Text += text + "\n";
        });
    }
}

Then my second class that is being run in a second thread (because it is a long process)

// File: Class.cs

using Form1;

namespace Form1
{
    public void DoSomething() // Called in Form1
    {
        // Does stuff

        string TextToGoBack; // Has text when DoSomething runs

        // Here is where I get stuck
        Form form = Form1.ActiveForm;

        form.SetText(TextToGoBack); // SetText is not showing up here no matter what I do
    }
}

EDIT:

I would not be opposed to using custom events to accomplish the same thing, but I am having a tough time figuring those out as well.

Answer 1

Form.ActiveForm returns a Form object, not the instance of your Form1 class, so does not have a SetText method.

You could cast it to a Form1, but that would be brittle. I would pass the instance of Form1 to your DoSomething method.