每次更改其属性时如何更新 UI 上的控件

Question

I have to work on a C# GUI application that displays information regarding an alternator that sends back messages every 20ms. So whenever I receive a certain message for ex regarding the temperature, I have to update a Textbox's text property on the UI with the correct information. The problem is I have tried using multithreading with delegates, did not work, and using invoke's did not work. Using a thread pool didn't work. I just want a chunk of code that forces the UI to update a textbox's text property and never thought this could be that hard.

At the moment I have this:

delegate void UpdateTextBoxTextDelegate(double newValue);
        private void UpdateTextBoxText(double newValue)
        {
            if(tbxTemp.InvokeRequired)
            {
                UpdateTextBoxTextDelegate del = new UpdateTextBoxTextDelegate(UpdateTextBoxText);
                tbxTemp.Invoke(del, new object[] {newValue});
            }
            else
            {
                tbxTemp.Text = Convert.ToString(newValue + "°C");
            }
        }
private double alternatorTemperature;
        public double _alternatorTemperature
        {
            get { return alternatorTemperature; }
            set
            {
                alternatorTemperature = value;
                UpdateTextBoxText(alternatorTemperature);
            }
        }

And then I have this function which is basically executing every time a CAN message is received with a certain PGN. This function call hierarchy basically leads back up to the main thread of the application, not the UI thread if that helps.

//Alternator Temperature
                case 0xFEA7:
                    temp = (UInt16)(canMessage.Data4);
                    alternatorTemperature = Convert.ToDouble(temp);
                    _alternatorTemperature = alternatorTemperature;
                    break;

The following code changes the textbox text almost 20 seconds later after there have been thousands of messages sent which is not acceptable. I have also tried the invoke way but only has the same delayed result

tbxRPM.Invoke(new Action(() => tbxRPM.Text = alternatorRPM.ToString() + "/rpm"));

If anyone has an easy way of changing a textbox.text property and then have it immediately show up on the UI, it would be great.

Answer 1

I would recomend you to create a class representing your "Alternator" with a property for "Temperature" and one method for "GetTemperature" that would be the same has your "function which is basically executing every time a CAN message is received with a certain PGN". Once it is done, bind your textbox to the instatiated class and property using:

tbxTemp.DataBindings.Add("Text",
                          objAlternator,
                          "Temperature",
                          false,
                          DataSourceUpdateMode.OnPropertyChanged);

Answer 2

In the end, the method I used to force UI controls to change even though the main thread was busy all the time was the following. I used this method on text boxes and it turned out to be very responsive

private string _someVariable = "Initial text";
        public string SomeVariable
        {
            get { return _someVariable; }
            set { _someVariable= value;
                if(PropertyChanged != null)
                {
                    PropertyChanged(this,new System.ComponentModel.PropertyChangedEventArgs(SomeVariable));
                }
            }
        }

Within the main form's constructor I added the following:

lblTextBox.DataBindings.Add("Text", this, "SomeVariable");

And then to trigger changes on the UI controls when I needed I just changed the text property of the textbox you bound the data to and it just worked without the need for multi-threading, delegates, or any complex stuff. eg. Where you need a control to change:

lblTextBox.Text = "Some text";