View注入框架：Butterknife简单使用
View注入框架 下载地址
1.Activity Binging
通过@Bind注释字段，
Butter Knife可以通过View的ID自动找到并把相应的视图布局。
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...
}
}
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public void bind(ExampleActivity activity) {
activity.subtitle = (android.widget.TextView) activity.findViewById(2130968578);
activity.footer = (android.widget.TextView) activity.findViewById(2130968579);
activity.title = (android.widget.TextView) activity.findViewById(2130968577);
}
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2.Non Activity Binging
你可以指定Root View，从它中找到你
@Bind的View
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;
}
}
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3.Use in Adapter
在适配器列表中简化ViewHolder
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);
}
}
}
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4.View List
你可以将多个View分组存储到List或者Array中
@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);
}
};
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apply
方法
ButterKnife.apply(nameViews, View.ALPHA, 0.0f);
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5.Listener Binging
Listeners也可以自动配置方法
@OnClick(R.id.submit)
public void submit(View view) {
// TODO submit data to server...
}
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所有的Listener的参数是可选的
@OnClick(R.id.submit)
public void submit() {
// TODO submit data to server...
}
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定义一个特定的类型它可以自动的转换
@OnClick(R.id.submit)
public void sayHi(Button button) {
button.setText(
"Hello!"
);
}
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在同一个绑定事件处理中可以指定多个ID
@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();
}
}
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public class FancyButton extends Button {
@OnClick
public void onClick() {
// TODO do something!
}
}
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6.Binging Reset
Fragments 比Activity有不同的View生命周期，在Fragmrnt 的 onCreateView方法中绑定，onDestroyView方法中销毁Views。Butter Knife有unbind 方法自动去做。
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
);
}
}
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7.Optional Binging
为了抑制这种习惯常见了可选绑定，
@Nullable注解添加到字段或者方法中
笔记：
如何注解前都支持
@Nullable注解（官方鼓励这样的行为）
@Nullable @Bind(R.id.might_not_be_there) TextView mightNotBeThere;
@Nullable @OnClick(R.id.maybe_missing) void onMaybeMissingClicked() {
// TODO ...
}
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8.Multi-Method Listeners
方法注释相应的监听器有多个回调可以绑定到任何其中之一。每一个注释都 绑定到 一个默认的回调。 使用callback 参数 指定一个替代|
@OnItemSelected(R.id.list_view)
void onItemSelected(int position) {
// TODO ...
}
@OnItemSelected(value = R.id.maybe_missing, callback = NOTHING_SELECTED)
void onNothingSelected() {
// TODO ...
}
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9.Bonus
还包含findById方法的简化依然需要知道Views在哪个view、Activity、Dialog。它使用泛型来推断返回类型,并自动执行。
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);
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注意：
使用Android Studio 需要在
Gradle文件中添加
compile
'com.jakewharton:butterknife:(insert latest version)'
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混淆编译的时候需要在proguard文件中添加
-keep class butterknife.** { *; }
-dontwarn butterknife.internal.**
-keep class **$$ViewBinder { *; }
-keepclasseswithmembernames class * {
@butterknife.* <fields>;
}
-keepclasseswithmembernames class * {
@butterknife.* <methods>;
}
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