Butterknife 简单使用

介绍

Activity中使用@Bind来对id进行绑定。

class ExampleActivity extends Activity {
@Bind(R.id.title) TextView title;
@Bind(R.id.subtitle) TextView subtitle;
@Bind(R.id.footer) TextView footer;

@Override public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.simple_activity);
ButterKnife.bind(this);
// TODO Use fields...
}
}

在Fragment中使用：

public class FancyFragment extends Fragment {
@Bind(R.id.button1) Button button1;
@Bind(R.id.button2) Button button2;

@Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fancy_fragment, container, false);
ButterKnife.bind(this, view);
// TODO Use fields...
return view;
}
}

在ViewHolder中使用：

public class MyAdapter extends BaseAdapter {
@Override public View getView(int position, View view, ViewGroup parent) {
ViewHolder holder;
if (view != null) {
holder = (ViewHolder) view.getTag();
} else {
view = inflater.inflate(R.layout.whatever, parent, false);
holder = new ViewHolder(view);
view.setTag(holder);
}

holder.name.setText("John Doe");
// etc...

return view;
}

static class ViewHolder {
@Bind(R.id.title) TextView name;
@Bind(R.id.job_title) TextView jobTitle;

public ViewHolder(View view) {
ButterKnife.bind(this, view);
}
}
}

绑定时机：
在 activity 中使用 ButterKnife.bind(this, activity)，进行绑定。
Bind a view's children into fields using ButterKnife.bind(this).
自定义view中在onFinishInflate() 进行绑定。

多个View或者数组等进行绑定：

@Bind({ R.id.first_name, R.id.middle_name, R.id.last_name })
List<EditText> nameViews;

The apply method allows you to act on all the views in a list at once.

ButterKnife.apply(nameViews, DISABLE);
ButterKnife.apply(nameViews, ENABLED, false);

Action and Setter interfaces allow specifying simple behavior.

static final ButterKnife.Action<View> DISABLE = new ButterKnife.Action<View>() {
@Override public void apply(View view, int index) {
view.setEnabled(false);
}
};
static final ButterKnife.Setter<View, Boolean> ENABLED = new ButterKnife.Setter<View, Boolean>() {
@Override public void set(View view, Boolean value, int index) {
view.setEnabled(value);
}
};

An Android Property can also be used with the apply method.

ButterKnife.apply(nameViews, View.ALPHA, 0.0f);

LISTENER 绑定

@OnClick(R.id.submit)
public void submit(View view) {
// TODO submit data to server...
}

在listener 中，所有参数可选。

@OnClick(R.id.submit)
public void submit() {
// TODO submit data to server...
}

@OnClick(R.id.submit)
public void sayHi(Button button) {
button.setText("Hello!");
}

多个view绑定同一个监听器

@OnClick({ R.id.door1, R.id.door2, R.id.door3 })
public void pickDoor(DoorView door) {
if (door.hasPrizeBehind()) {
Toast.makeText(this, "You win!", LENGTH_SHORT).show();
} else {
Toast.makeText(this, "Try again", LENGTH_SHORT).show();
}
}

自定义Views的自身的事件绑定

public class FancyButton extends Button {
@OnClick
public void onClick() {
// TODO do something!
}
}

BINDING RESET

Fragment解绑

public class FancyFragment extends Fragment {
@Bind(R.id.button1) Button button1;
@Bind(R.id.button2) Button button2;

@Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fancy_fragment, container, false);
ButterKnife.bind(this, view);
// TODO Use fields...
return view;
}

@Override public void onDestroyView() {
super.onDestroyView();
ButterKnife.unbind(this);
}
}

OPTIONAL BINDINGS 可选绑定

By default, both @Bind and listener bindings are required. An exception will be thrown if the target view cannot be found.

To suppress this behavior and create an optional binding, add a @Nullable annotation to the field or method.

Note: Any annotation named @Nullable can be used for this purpose. It is encouraged to use the @Nullable annotation from Android's "support-annotations" library, see Android Tools Project.

@Nullable @Bind(R.id.might_not_be_there) TextView mightNotBeThere;

@Nullable @OnClick(R.id.maybe_missing) void onMaybeMissingClicked() {
// TODO ...
}

MULTI-METHOD LISTENERS

Method annotations whose corresponding listener has multiple callbacks can be used to bind to any one of them. Each annotation has a default callback that it binds to. Specify an alternate using the callback parameter.

@OnItemSelected(R.id.list_view)
void onItemSelected(int position) {
// TODO ...
}

@OnItemSelected(value = R.id.maybe_missing, callback = NOTHING_SELECTED)
void onNothingSelected() {
// TODO ...
}

BONUS 额外的

Also included are findById methods which simplify code that still has to find views on a View, Activity, or Dialog. It uses generics to infer the return type and automatically performs the cast.

View view = LayoutInflater.from(context).inflate(R.layout.thing, null);
TextView firstName = ButterKnife.findById(view, R.id.first_name);
TextView lastName = ButterKnife.findById(view, R.id.last_name);
ImageView photo = ButterKnife.findById(view, R.id.photo);
Add a static import for ButterKnife.findById and enjoy even more fun.

MAVEN 配置

<dependency>
<groupId>com.jakewharton</groupId>
<artifactId>butterknife</artifactId>
<version>7.0.1</version>
</dependency>

GRADLE配置

compile 'com.jakewharton:butterknife:7.0.1'

Be sure to suppress this lint warning in your build.gradle.

lintOptions {

disable 'InvalidPackage'

}

Some configurations may also require additional exclusions.

packagingOptions {

exclude 'META-INF/services/javax.annotation.processing.Processor'

}

混淆配置

-keep class butterknife.** { *; }
-dontwarn butterknife.internal.**
-keep class **$$ViewBinder { *; }

-keepclasseswithmembernames class * {
@butterknife.* <fields>;
}

-keepclasseswithmembernames class * {
@butterknife.* <methods>;
}

原文是其官方文档： http://jakewharton.github.io/butterknife/