Question

我想从工作线程修改计时器的间隔值，该计时器是System.Microsoft.Timer的实例当我在线程运行的工作线程中更改此值时，Timer停止。

让我看看我的源代码

    private void Scan_Screen(object sender, EventArgs e)
    {
        textBox1.Text += "a";
    }
    private void button1_Click(object sender, EventArgs e)
    {

        g_RECEIVER_timer = new System.Windows.Forms.Timer();
        g_RECEIVER_timer.Enabled = true;
        g_RECEIVER_timer.Interval = TIMER_INTERVAL;
        g_RECEIVER_timer.Tick += new EventHandler(Scan_Screen);
    }

    private void button2_Click(object sender, EventArgs e)
    {
        g_Control_Thread = new Thread(new ParameterizedThreadStart(Control_Message_Receiver));
        g_Control_Thread.Start(200); 
    }
    //thread function
    public void Control_Message_Receiver(object v)
    { 
        g_RECEIVER_timer.Stop();
        g_RECEIVER_timer.Interval = 200;
        g_RECEIVER_timer.Enabled = true;
        g_RECEIVER_timer.Tick += new EventHandler(Scan_Screen);
    }

为什么会发生这种情况？另外我怎么能跑这个？（我想在工作线程中调整计时器的间隔值）

Answer 1

您需要在UI线程上调用此Control_Message_Receiver，因为您已经生成了另一个工作线程，并且您正在访问UI线程上下文中的对象。

并且不需要在工作线程方法上重新声明Tick事件。

请看下面的这个片段：

    private void Scan_Screen(object sender, EventArgs e)
    {
        textBox1.Text += "a";
    }

    private void button1_Click(object sender, EventArgs e)
    {
        g_RECEIVER_timer = new System.Windows.Forms.Timer();
        g_RECEIVER_timer.Enabled = true;
        g_RECEIVER_timer.Interval = 1000;
        g_RECEIVER_timer.Tick += new EventHandler(Scan_Screen);
    }

    private void button2_Click(object sender, EventArgs e)
    {
        Thread g_Control_Thread = new Thread(new ParameterizedThreadStart(Control_Message_Receiver));
        g_Control_Thread.Start(1);
    }

    //thread function
    public void Control_Message_Receiver(object v)
    {
        //timer1.Stop(); //why stop? -- remove this instead
        IntervalChange((int)v); //call this method and invoke it on the UI thread
        g_RECEIVER_timer.Enabled = true;
        //timer1.Tick += new EventHandler(Scan_Screen); // -- remove this
    }

    delegate void intervalChanger(int time);

    void ChangeInterval(int time)
    {
        g_RECEIVER_timer.Interval = time;
    }

    void IntervalChange(int time)
    {
        this.Invoke(new intervalChanger(ChangeInterval), new object[] {time}); //invoke on the UI thread
    }

Answer 2

使用System.Threading.Timer可能更好。这个可以从任何线程重新调整。但请注意，计时器回调在线程池线程中运行。因此，如果需要从此回调访问GUI，则必须使用Invoke。

C＃，Form.Timer间隔值在工作线程中调整

2 个答案: