Remove “Method is never used” warning for OnClick annotation in Android Studio

Question

Sorry if this question has been asked before. I am using the Butterknife 5.0 with the latest version of Android Studio(0.5.7). How can I remove the \"Method is never used\"

Answer 1

Osvald's answer is spot on.

However, if you want to avoid suppressing warnings separately for each type of butterknife annotation, follow his instructions, and then open up .idea/misc.xml and find this section:

<component name="EntryPointsManager">
  <entry_points version="2.0" />
  <list size="1">
    <item index="0" class="java.lang.String" itemvalue="butterknife.OnClick" />
  </list>
</component>

Therein, simply replace butterknife.OnClick with butterknife.*.

From now on, all your injected event handlers will evade the warning.

Answer 2

The correct way in Android Studio to suppress these warnings is to press Alt+Enter on the method giving the Method 'yourFunction()' is never used warning, and selecting

Suppress for methods annotated by 'butterknife.OnClick'

Answer 3

Simply add this annotation:

@SuppressWarnings("unused")

Just like that:

@SuppressWarnings("unused")
@OnClick(R.id.myButton)
public void clickHandler()
{
    // ...
}

My personal preference (which I see as good practice) is to add a comment with a brief explanation:

@SuppressWarnings("unused") // it's actually used, just injected by Butter Knife

Answer 4

Add another dependency for the compiler:

Gradle

dependencies {
    annotationProcessor 'com.jakewharton:butterknife-compiler:8.4.0' // new line
    compile 'com.jakewharton:butterknife:8.4.0' // original library
}

This is recommended on the official website.

Remember to Build -> Rebuild Project, so it will generate usages and make the warning go away.