Android Button Illegalstateexception With Onclick(mainactivity)

Brand new to android. I have a button that is supposed to trigger an onClick method that is an override of the onClick method used with the onClickListener. The problem is that whe

Solution 1:

Why is this?

Because android:onClick="onClick" is correct syntax. None of the following are correct syntax:

• android:onClick="onClick (MainActivity)"
• android:onClick="onClick (View)"
• android:onClick="onClick(View)"
• android:onClick="onClick and anything else"

Quoting the documentation for android:onClick:

Name of the method in this View's context to invoke when the view is clicked. This name must correspond to a public method that takes exactly one parameter of type View. For instance, if you specify android:onClick="sayHello", you must declare a public void sayHello(View v) method of your context (typically, your Activity).

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OK, with the help of @HappyRavi on Twitter, I was able to reproduce the problem. It's an IDE bug that you will encounter if you do things in a certain order:

• Add the method that you want to route the click event to
• Drag the Button into the GUI editor
• Click the onClick drop-down in the Properties pane of the GUI editor

Doing things in a different order will not reproduce the problem.

With luck, they can get this fixed in some patch release for Android Studio 2.3.

Solution 2:

It should be implemented like below

<Button
android:text="Accept"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/editText2"
android:layout_centerHorizontal="true"
android:layout_marginTop="84dp"
android:id="@+id/button2"
android:onClick="buttonClickHandler" />//name of method should be given here

And add the method in Activity file

publicvoidbuttonClickHandler(View view) {
  //handle button click here
}

This will work only when method is added in Activity class and not with Fragment