Butter Knife
Attention: Development on this tool is winding down. Please consider switching to
view binding in the coming months.
Field and method binding for Android views which uses annotation processing to generate boilerplate
code for you.
- Eliminate
findViewByIdcalls by using@BindViewon fields. - Group multiple views in a list or array. Operate on all of them at once with actions,
setters, or properties. - Eliminate anonymous inner-classes for listeners by annotating methods with
@OnClickand others. - Eliminate resource lookups by using resource annotations on fields.
class ExampleActivity extends Activity {
@BindView(R.id.user) EditText username;
@BindView(R.id.pass) EditText password;
@BindString(R.string.login_error) String loginErrorMessage;
@OnClick(R.id.submit) void submit() {
// TODO call server...
}
@Override public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.simple_activity);
ButterKnife.bind(this);
// TODO Use fields...
}
}
For documentation and additional information see the website.
Remember: A butter knife is like a dagger, only infinitely less sharp.
Download
android {
...
// Butterknife requires Java 8.
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
}
dependencies {
implementation 'com.jakewharton:butterknife:10.2.1'
annotationProcessor 'com.jakewharton:butterknife-compiler:10.2.1'
}
If you are using Kotlin, replace annotationProcessor with kapt.
Snapshots of the development version are available in Sonatype's snapshots repository.
Library projects
To use Butter Knife in a library, add the plugin to your buildscript:
buildscript {
repositories {
mavenCentral()
google()
}
dependencies {
classpath 'com.jakewharton:butterknife-gradle-plugin:10.2.1'
}
}
and then apply it in your module:
apply plugin: 'com.android.library'
apply plugin: 'com.jakewharton.butterknife'
Now make sure you use R2 instead of R inside all Butter Knife annotations.
class ExampleActivity extends Activity {
@BindView(R2.id.user) EditText username;
@BindView(R2.id.pass) EditText password;
...
}
License
Copyright 2013 Jake Wharton
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.