无法使用 COM 接口和 DLL 在 CANape 上开始测量

我试图在 CANoe 开始运行时启动 CANape 上的测量。 我试过以下方法：

public override void Main()
{
 _application = new CANAPELib.ApplicationClass()；
 _iApplication2 = _application；
 _iMeasurement = _iApplication2.Measurement as CANAPELib.IMeasurement；
bool isRunning = Vector.Tools.Measurement.IsRunning; //CANOE RUNNING
如果 (isRunning)
{
    尝试
    {
        _iMeasurement.Start()；
    }catch (Exception ex) {
        LogError(ex.Message)；
    }
}

}

我在异常中遇到了以下问题：

我在异常中得到了如下信息：

05/30/2024 09:33:16: CMeasurement.Start( - No valid handle

05/30/2024 09:33:16: CMeasurement.Start() - No valid handle

The error message "CMeasurement.Start() - No valid handle" indicates that the _iMeasurement object in your code does not have a valid reference to a CANape measurement. This is likely because you are attempting to start the measurement before CANape has fully initialized and loaded the configuration.

Here's a breakdown of the issue and possible solutions:

Problem:

• Timing: You're trying to start the CANape measurement as soon as CANoe starts. However, CANape might take a moment to initialize itself, load the configuration, and create the necessary objects. If you try to access _iApplication2.Measurement too early, it might not be available yet, resulting in a null reference or an invalid handle.

Solutions:

1. Delay and Retry: Introduce a delay before attempting to start the measurement. This will give CANape enough time to initialize:

```csharp public override void Main() { _application = new CANAPELib.ApplicationClass(); _iApplication2 = _application;

   // Introduce a delay (e.g., 2 seconds)
   System.Threading.Thread.Sleep(2000);

   _iMeasurement = _iApplication2.Measurement as CANAPELib.IMeasurement;
   bool isRunning = Vector.Tools.Measurement.IsRunning;

   if (isRunning && _iMeasurement != null) // Check if _iMeasurement is valid
   {
       try
       {
           _iMeasurement.Start();
       }
       catch (Exception ex) 
       {
           LogError(ex.Message);
       }
   }
   else
   {
       LogError("CANape Measurement is not initialized yet.");
   }

} ```

1. Event-Based Approach: Use CANape events to get notified when the measurement is ready. This is a more robust approach as you won't rely on arbitrary delays:

```csharp // ... (Your class definition)

private CANAPELib.IMeasurementEvents_OnMeasurementStateChangedEventHandler _measurementStateChangedEventHandler;

public override void Main() { _application = new CANAPELib.ApplicationClass(); _iApplication2 = _application; _iMeasurement = _iApplication2.Measurement as CANAPELib.IMeasurement;

   // Subscribe to the OnMeasurementStateChanged event
   _measurementStateChangedEventHandler = new CANAPELib.IMeasurementEvents_OnMeasurementStateChangedEventHandler(OnMeasurementStateChanged);
   ((CANAPELib.IMeasurementEvents_Event) _iMeasurement).OnMeasurementStateChanged += _measurementStateChangedEventHandler;

   // ... rest of your code

}

private void OnMeasurementStateChanged(CANAPELib.MeasurementStateEnum state) { if (state == CANAPELib.MeasurementStateEnum.msReady) // Measurement is ready { try { _iMeasurement.Start(); } catch (Exception ex) { LogError(ex.Message); } } } ```

Important Notes:

• Error Handling: Always include robust error handling (like you have with the try-catch block) to catch any potential exceptions during the CANape interaction.
• Documentation: Refer to the CANape and CANoe COM API documentation from Vector for details on event handling, object models, and specific methods available.

By implementing one of these solutions, you can ensure that your code interacts with CANape correctly and avoids the "No valid handle" error.