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" warning for methods that use the 'OnClick' Annotation of ButterKnife.I noticed that Eclipse doesnt give this warning for the 'OnClick' methods. Thanks in advance

https://stackoverflow.com/a/54816338/3007795 - kind of same – Joyal Feb 21 '19 at 21:22 — Joyal, Feb 21 '19 at 21:22

score 96 · Accepted Answer · answered May 13 '14 at 12:07

96

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'

answered May 13 '14 at 12:07

Osvald Ivarsson

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how do you undo this action? – Adam Johns Aug 06 '15 at 15:08
FYI, it adds exactly what @codesparkle said (tested with AS 2.0) – seb Feb 01 '16 at 10:53

Konrad Morawski · Answer 2 · 2014-05-03T20:54:37.637

91

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

edited May 03 '14 at 20:54

answered May 03 '14 at 20:02

Konrad Morawski

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it can be more detailed: @SuppressWarnings({"UnusedDeclaration"}) @SuppressWarnings({"UnusedParameters"}) – AndrewS Nov 16 '15 at 16:46
@SuppressWarnings("unused") did not work for me, but @Suppress("unused") did. – Greelings Jul 12 '22 at 11:20

score 11 · Answer 3 · answered Feb 15 '15 at 00:18

11

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.

answered Feb 15 '15 at 00:18

Adam

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Not bad, but I think one doesn't usually commit `.idea` files into the repository, so every developer has to do this trick individually, whereas an annotation works automatically for everyone since it's an integral part of the codebase – Konrad Morawski May 11 '15 at 14:21
@KonradMorawski Both methods only change `.idea` files so you'd have the same issue either way. What is and is not committed to a repository depends entirely on what the repository is configured to ignore. – Tom Aug 18 '15 at 03:11
@Tom no, SuppressWarnings is an annotation used in code files directly – Konrad Morawski Aug 18 '15 at 18:15
Oh I see, I was referring to Osvald's and Codesparkle's answers, which only change .idea/misc.xml file. You meant annotations. I'll just shuffle over here... – Tom Aug 18 '15 at 23:35

score 5 · Answer 4 · answered Oct 16 '16 at 18:21

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.

Greelings · Answer 5 · 2022-09-20T11:10:26.600

2

With Kotlin, you should use @Suppress("unused") instead of @SuppressWarnings("unused")

@Suppress("unused") 
fun foo() {

}

edited Sep 20 '22 at 11:10

answered Jul 12 '22 at 11:24

Greelings

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

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