无法中止线程

Question

我正在尝试进行设置，因此当我单击按钮时，它会关闭/中止当前正在运行的线程。我也尝试过使用Thread.IsAlive.ToString，但是即使我看到它总是返回false线程正在运行（仍在richtextbox上显示文本）。

    Thread scheduler => new Thread(Work);
    public void Work()
        {
            SetText();

        }

        private void Button10_Click(object sender, EventArgs e)
        {
            //button that should stop thread
            scheduler.Abort();
        }

        private void WriteTextSafe(string text)
        {
            if (richTextBox1.InvokeRequired)
            {
                var d = new SafeCallDelegate(WriteTextSafe);
                Invoke(d, new object[] { text });
            }
            else
            {
                richTextBox1.AppendText(text);
            }
        }

        private void SetText()
        {
            WriteTextSafe("This text was set safely.\n");
            System.Threading.Thread.Sleep(3000);
            WriteTextSafe("This text was set safely.\n");

        }