C＃ - backgroundworker通過串行從Arduino連續獲取數據

Question

因此，我有這個從Arduino獲取值（6個變量）的C＃應用​​程序。最初我使用了一個計時器，每100ms調用一次讀取函數，但它會掛起我的用戶界面，並且響應有點沉重。我想使用一個連續讀取這些變量的背景工作。我將這些讀取的調用放在DoWork方法中，並將值放入C＃中的變量中，並將它們分配到標籤中。但它不起作用。 （對不起，我的英語）

namespace testtemp 
{ 
    public partial class tempreaderform : Form 
    { 
     public tempreaderform() 
     { 
      InitializeComponent(); 
     } 

communicator comport = new communicator(); 
Boolean portConnection = false; 
String red_light1; 

private void button1_Click(object sender, EventArgs e) 
     { 
      if (comport.connect(57600, "I'M ARDUINO", 4, 8, 16)) 
      { 
       label1.Text = "Connection Successful - Connected to "+comport.port; 
       portConnection = true; 
       backgroundWorker1.RunWorkerAsync(); // I am not sure if here I should start the backgroundworker. 
      } 
      else 
      { 
       label1.Text = "Not connected . . . "; 
       portConnection = false; 
      } 
     } 

     private void groupBox1_Paint(object sender, PaintEventArgs e) 
     { 
      Graphics ellipse1 = groupBox1.CreateGraphics(); 

      Brush red_on = new SolidBrush(Color.Red); 
      Brush red_off = new SolidBrush(Color.DarkRed); 

      label2.Text = "Red : " + red_light1; //Here is a label which I want to show "1" if "red_light1" is "1" and "0" if "red_light1" is "0" 

      if (red_light1 == "1") ellipse1.FillEllipse(red_on, 250, 133, 24, 24); 
          else ellipse1.FillEllipse(red_off, 250, 133, 24, 24); // Here is what I really want to do (the label.Text part was only to see the value) I want to color a ellipse depending on "red_light1" value. 

     } 



private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) 
     { 
      while (true) 
      { 
       red_light1 = comport.message(4, 8, 32); 
      } 
     } 
} 
} 
} 

注：我的DoWork方法tryied這個「label1.Text = red_light1」，但它說，我不能在另一個線程創建的變量給值，這樣的事情。

Answer 1

「問題」是背景工作者生活在另一個線程中，而您嘗試在UI線程中使用它。而這條消息並沒有在那裏傳達。

有三個選項：

1. 要使用RunWorkerCompleted事件：你必須使用一個計時器來運行的BackgroundWorker每隔X毫秒。

   private void timer1_Tick(object sender, EventArgs e) { 
       this.backgroundworker.RunWorkerAsync(); 
   } 
   
   
   private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) 
       e.Result = comport.message(4, 8, 32); 
   } 
   
   private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) { 
       label2.Text = e.Result.ToString(); 
   } 
   

2. 使用BeginInvoke設置文本

   private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) 
   { 
       while (true) 
       { 
        this.BeginInvoke((Action)(() => { label2.Text = comport.message(4, 8, 32); }); 
   
        // add some delay here as well... 
       } 
   } 
   

3. 使用Task而不是BackgroundWorker的，並調用它的計時器。

   private void timer1_Tick(object sender, EventArgs e) { 
       Task.Run(() => { 
       this.BeginInvoke((Action)(() => { label2.Text = comport.message(4, 8, 32); }); 
       }); 
   } 
   

Answer 2

可以使用ReportProgress事件：

1. 設置WorkerReportsProgress爲true

2. 寫事件處理程序：

   private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e) 
   { 
       String mytext = e.UserState as String; 
       myLabel.Text = mytext; 
   } 
   

3. 個電話在DoWork的

   private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) 
   { 
       BackgroundWorker bgw = sender as BackgroundWorker; 
       String receivedtext; 
       while (true) 
       { 
        myreceivedtext = comport.message(4, 8, 32); 
        bgw.ReportProgress(0, myreceivedtext); 
        System.Threading.Thread.Sleep(100); 
       } 
   }