How to call method with View Parameter on Android Studio

Question

I want to call this method

public void openButton(View view) {
    Intent intent = new Intent(this, MainActivity.class);
    this.startActivity(intent);
}

from simple method like this

public void simple(){
    openButton();
}

but I can't do it because openButton needs one parameter View. How?

Answer 1

Simple. Just pass the view in arguments.

Way 1: if you are calling openButton() method from layout file then, simply call method the following way by applying onClick attribute

<Button
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:text="Go to next screen"
   . . . 
   android:onClick="openButton" />

Way 2: if you are trying to call it from button's onclick by setting OnClickListener, then, simply pass the view you are getting inside OnClickListener's onClick(View view) method as follows:

button.setOnClickListener(new OnClickListener(){

    @override
    public void onClick(View view)
    {
       openButton(view);
    }

});

Answer 2

Well, with the code that you provided, you usually use some sort of an onCickListener.

Open your XML file, and add android:onClick="openButton" to the button that you want to call that method. So your XML for the button will look something like this:

<Button
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:text="Click me!"
   . . . 
   android:onClick="openButton" />

That will automatically call that method and pass in a view.

The other option, as BatScream mentioned in the comments, is to just pass in null, as you aren't using the view anyway. HOWEVER, this is bad practice - it'll work this time, but in general, you should follow the system that Android uses. Just go with an onClick in the XML.

---

If you HAVE to use simple the way it is, do it this way:

public void simple(){
    openButton(null);
}