Subscribing to events

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Subscribe to any .NET event with Javonet. Event subscription works the same way as listening Java events. The performance of event subscription is extremely high and allows you to interact with .NET code like it was native Java code. When the event occurs, your Java listener callback is called in a separate thread.
The simplest way to subscribe an event is to use an anonymous Java class.

Assuming we have a custom .NET Framework DLL with the following class inside:

namespace TestClass
{
	public class TestClass
	{
		public TestClass() { }

		namespace TestNamespace
		{
			public delegate void EventExampleHandler(object sender, string e);
		
			public class EventExample
			{
				public event EventExampleHandler SampleEvent;
		
				public void EventInvoke()
				{
					if (SampleEvent != null)
						SampleEvent(this, "Called from .NET!");
				}
			}
		}
		
	}
}
namespace TestNamespace
{
	public delegate void EventExampleHandler(object sender, string e);

	public class EventExample
	{
		public event EventExampleHandler SampleEvent;

		public void EventInvoke()
		{
			if (SampleEvent != null)
				SampleEvent(this, "Called from .NET!");
		}
	}
}

The anonymous class should implement special INEventListener interface to subscribe to .NET event.

import com.javonet.sdk.java.Javonet;
import com.javonet.sdk.internal.InvocationContext;
import com.javonet.sdk.internal.RuntimeContext;

public class SampleProgram {

    private static final String resourcesDirectory = ".";
    public static void main(String []args) {

        // Todo: activate Javonet and add reference to .NET library
        
        NObject sampleObj = Javonet.New("TestNamespace.EventExample");
        sampleObj.addEventListener("SampleEvent", new INEventListener() {
            public void eventOccurred(Object[] arguments) {
                System.out.println(arguments[1]);
            }
        });
        sampleObj.invoke("EventInvoke");
     }
}// Todo: activate Javonet and add reference to .NET library

NObject sampleObj = Javonet.New("TestNamespace.EventExample");
sampleObj.addEventListener("SampleEvent", new INEventListener() {
    public void eventOccurred(Object[] arguments) {
        System.out.println(arguments[1]);
    }
});
sampleObj.invoke("EventInvoke");

Using .NET standard library elements

To create a .NET button and listen for a "Click" event:

import com.javonet.sdk.java.Javonet;
import com.javonet.sdk.internal.InvocationContext;
import com.javonet.sdk.internal.RuntimeContext;

public class SampleProgram {

    private static final String resourcesDirectory = ".";
    public static void main(String []args) {

        // Todo: activate Javonet
        
        Javonet.addReference("System.Windows.Forms.dll");
        
        NObject button = Javonet.New("System.Windows.Forms.Button");
        button.set("Text", "Click me!");
        
        button.addEventListener("Click", new INEventListener() {
            public void eventOccurred(Object[] arguments) {
                System.out.println(".NET event occurred");
            }
        });
     }
}// Todo: activate Javonet

Javonet.addReference("System.Windows.Forms.dll");

NObject button = Javonet.New("System.Windows.Forms.Button");
button.set("Text", "Click me!");

button.addEventListener("Click", new INEventListener() {
    public void eventOccurred(Object[] arguments) {
        System.out.println(".NET event occurred");
    }
});

The anonymous class should implement special INEventListener interface. Alternatively you can write a separate class as the event listener by extending NEventListener and overriding the eventOccurred method, or by implementing the ((INEventListener)) interface.

namespace TestClass
{
	public class TestClass
	{
		public TestClass() { }

		package utils;
		
		import com.javonet.api.INEventListener;
		
		//Your custom Java listener class for .NET events
		public class MyEventListener implements INEventListener {
		    @Override
		    public void eventOccurred(Object[] arguments) {
		        System.out.println(".NET Event Occurred");
		    }
		}
	}
}
package utils;

import com.javonet.api.INEventListener;

//Your custom Java listener class for .NET events
public class MyEventListener implements INEventListener {
    @Override
    public void eventOccurred(Object[] arguments) {
        System.out.println(".NET Event Occurred");
    }
}

Usage of your listener class:

import com.javonet.sdk.java.Javonet;
import com.javonet.sdk.internal.InvocationContext;
import com.javonet.sdk.internal.RuntimeContext;

public class SampleProgram {

    private static final String resourcesDirectory = ".";
    public static void main(String []args) {

        // Todo: activate Javonet
        
        Javonet.addReference("System.Windows.Forms.dll");
        
        NObject button = Javonet.New("System.Windows.Forms.Button");
        button.set("Text", "Click me!");
        
        MyEventListener listener = new MyEventListener();
        button.addEventListener("Click", listener);
     }
}// Todo: activate Javonet

Javonet.addReference("System.Windows.Forms.dll");

NObject button = Javonet.New("System.Windows.Forms.Button");
button.set("Text", "Click me!");

MyEventListener listener = new MyEventListener();
button.addEventListener("Click", listener);

See Live Example!

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