最近剛學會使用ButterKnife,真是超級好用,忍不住要分享給大家了。
寫在前面:該文檔使用7.0版本,8.0版本方法名有所改動,建議看官方文檔,整體業務邏輯和原理沒什麼變動。
在Android編程過程中,我們會寫大量的佈局和點擊事件,像初始view、設置view監聽這樣簡單而重複的操作讓人覺得麻煩類,所以可以採用註解的方式去實現,而ButterKnife則是註解中相對簡單易懂的很不錯的開源框架,而網上的文檔和例子都過時了,7.0之後的版本改動很大,之前的註解都不能用了,所以借鑑官方文檔總結了一下,接下來就介紹一下如何使用。基本參照官方文檔,加上自己的心得。
ButterKnife 優勢:
1.強大的View綁定和Click事件處理功能,簡化代碼,提升開發效率
2.方便的處理Adapter裏的ViewHolder綁定問題
3.運行時不會影響APP效率,使用配置方便
4.代碼清晰,可讀性強
使用心得:
1.Activity ButterKnife.bind(this);必須在setContentView();之後,且父類bind綁定後,子類不需要再bind
2.Fragment ButterKnife.bind(this, mRootView);
3.屬性佈局不能用private or static 修飾,否則會報錯
4.setContentView()不能通過註解實現。(其他的有些註解框架可以)
官網http://jakewharton.github.io/butterknife/
使用步驟:
一.導入ButterKnife jar包:
1)如果你是Eclipse,可以去官網下載jar包
2)如果你是AndroidStudio可以直接 File->Project Structure->Dependencies->Library dependency 搜索butterknife即可,第一個就是
3)當然也可以用maven和gradle配置
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<span style="font-family:SimSun;font-size:14px;">MAVEN
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<dependency>
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<groupId>com.jakewharton</groupId>
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<artifactId>butterknife</artifactId>
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<version>(insert latest version)</version>
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</dependency>
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GRADLE
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compile 'com.jakewharton:butterknife:(insert latest version)'
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Be sure to suppress this lint warning in your build.gradle.(關閉)
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lintOptions {
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disable 'InvalidPackage'
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} </span>
注意如果在Library 項目中使用要按如下步驟(github中有具體描述)否則無法找到view:
注:官網和github也有對應的引用步驟。
二.常見使用方法:
1)由於每次都要在Activity中的onCreate綁定Activity,所以個人建議寫一個BaseActivity完成綁定,子類繼承即可
注:ButterKnife.bind(this);綁定Activity 必須在setContentView之後:
實現如下(FragmentActivity 實現一樣):
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<span style="font-family:SimSun;font-size:14px;">public abstract class BaseActivity extends Activity {
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public abstract int getContentViewId();
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@Override
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protected void onCreate(Bundle savedInstanceState) {
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super.onCreate(savedInstanceState);
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setContentView(getContentViewId());
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ButterKnife.bind(this);
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initAllMembersView(savedInstanceState);
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}
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protected abstract void initAllMembersView(Bundle savedInstanceState);
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@Override
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protected void onDestroy() {
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super.onDestroy();
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ButterKnife.unbind(this);
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}
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} </span>
2)綁定fragment
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<span style="font-family:SimSun;font-size:14px;">public abstract class BaseFragment extends Fragment {
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public abstract int getContentViewId();
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protected Context context;
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protected View mRootView;
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@Nullable
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@Override
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public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
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mRootView =inflater.inflate(getContentViewId(),container,false);
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ButterKnife.bind(this,mRootView);
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this.context = getActivity();
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initAllMembersView(savedInstanceState);
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return mRootView;
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}
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protected abstract void initAllMembersView(Bundle savedInstanceState);
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@Override
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public void onDestroyView() {
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super.onDestroyView();
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ButterKnife.unbind(this);
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}
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} </span>
3)綁定view
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<span style="font-family:SimSun;font-size:14px;">@Bind(R.id.hello_world)
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TextView mHelloWorldTextView;
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@Bind(R.id.app_name)
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TextView mAppNameTextView;
4)綁定資源
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<span style="font-family:SimSun;font-size:14px;">@BindString(R.string.app_name)
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String appName;
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@BindColor(R.color.red)
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int textColor;
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@BindDrawable(R.mipmap.ic_launcher)
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Drawable drawable;
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@Bind(R.id.imageview)
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ImageView mImageView;
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@Bind(R.id.checkbox)
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CheckBox mCheckBox;
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@BindDrawable(R.drawable.selector_image)
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Drawable selector; </span>
5)Adapter ViewHolder 綁定
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<span style="font-family:SimSun;font-size:14px;">public class TestAdapter extends BaseAdapter {
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private List<String> list;
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private Context context;
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public TestAdapter(Context context, List<String> list) {
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this.list = list;
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this.context = context;
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}
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@Override
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public int getCount() {
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return list==null ? 0 : list.size();
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}
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@Override
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public Object getItem(int position) {
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return list.get(position);
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}
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@Override
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public long getItemId(int position) {
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return position;
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}
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@Override
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public View getView(int position, View convertView, ViewGroup parent) {
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ViewHolder holder;
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if (convertView == null) {
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convertView = LayoutInflater.from(context).inflate(R.layout.layout_list_item, null);
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holder = new ViewHolder(convertView);
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convertView.setTag(holder);
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} else {
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holder = (ViewHolder) convertView.getTag();
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}
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holder.textview.setText("item=====" + position);
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return convertView;
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}
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static class ViewHolder {
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@Bind(R.id.hello_world)
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TextView textview;
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public ViewHolder(View view) {
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ButterKnife.bind(this, view);
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}
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}
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} </span>
6)點擊事件的綁定:不用聲明view,不用setOnClickLisener()就可以綁定點擊事件
a.直接綁定一個方法
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<span style="font-family:SimSun;font-size:14px;">@OnClick(R.id.submit)
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public void submit(View view) {
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} </span>
b.所有監聽方法的參數是可選的
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<span style="font-family:SimSun;font-size:14px;">@OnClick(R.id.submit)
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public void submit() {
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} </span>
c.定義一個特定類型,它將自動被轉換
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<span style="font-family:SimSun;font-size:14px;">@OnClick(R.id.submit)
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public void sayHi(Button button) {
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button.setText("Hello!");
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}</span>
d.多個view統一處理同一個點擊事件,很方便,避免抽方法重複調用的麻煩
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<span style="font-family:SimSun;font-size:14px;">@OnClick({ R.id.door1, R.id.door2, R.id.door3 })
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public void pickDoor(DoorView door) {
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if (door.hasPrizeBehind()) {
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Toast.makeText(this, "You win!", LENGTH_SHORT).show();
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} else {
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Toast.makeText(this, "Try again", LENGTH_SHORT).show();
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}
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} </span>
e.自定義view可以綁定自己的監聽,不指定id
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<span style="font-family:SimSun;font-size:14px;">public class FancyButton extends Button {
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@OnClick
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public void onClick() {
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}
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} </span>
f.給EditText加addTextChangedListener(即添加多回調方法的監聽的使用方法),利用指定回調,實現想回調的方法即可,哪個註解不會用點進去看下源碼上的註釋就會用了
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<span style="font-family:SimSun;font-size:14px;">@OnTextChanged(value = R.id.mobileEditText, callback = OnTextChanged.Callback.BEFORE_TEXT_CHANGED)
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void beforeTextChanged(CharSequence s, int start, int count, int after) {
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}
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@OnTextChanged(value = R.id.mobileEditText, callback = OnTextChanged.Callback.TEXT_CHANGED)
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void onTextChanged(CharSequence s, int start, int before, int count) {
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}
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@OnTextChanged(value = R.id.mobileEditText, callback = OnTextChanged.Callback.AFTER_TEXT_CHANGED)
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void afterTextChanged(Editable s) {
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} </span>
7)對一組View進行統一操作
a.裝入一個list
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<span style="font-family:SimSun;font-size:14px;">@Bind({ R.id.first_name, R.id.middle_name, R.id.last_name })
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List<EditText> nameViews; </span>
b.設置統一處理
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<span style="font-family:SimSun;">static final ButterKnife.Action<View> DISABLE = new ButterKnife.Action<View>() {
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@Override public void apply(View view, int index) {
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view.setEnabled(false);
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}
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};
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static final ButterKnife.Setter<View, Boolean> ENABLED = new ButterKnife.Setter<View, Boolean>() {
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@Override public void set(View view, Boolean value, int index) {
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view.setEnabled(value);
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}
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};<span style="color: silver; line-height: normal; background-color: rgb(248, 248, 248);"> </span><a target=_blank href="http://blog.csdn.net/itjianghuxiaoxiong/article/details/50177549#" class="ViewSource" title="view plain" style="line-height: normal; color: rgb(160, 160, 160); text-decoration: none; border: none; padding: 1px; margin: 0px 10px 0px 0px; display: inline-block; width: 16px; height: 16px; text-indent: -2000px; background-image: url("images/default/ico_plain.gif"); background-attachment: initial; background-color: inherit; background-size: initial; background-origin: initial; background-clip: initial; background-position: 0% 0%; background-repeat: no-repeat;">view plain</a></span><span data-mod="popu_168" style="font-size: 9px; font-family: Verdana, Geneva, Arial, Helvetica, sans-serif; color: silver; line-height: normal;"> <a target=_blank href="http://blog.csdn.net/itjianghuxiaoxiong/article/details/50177549#" class="CopyToClipboard" title="copy" style="color: rgb(160, 160, 160); text-decoration: none; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; text-indent: -2000px; background-image: url("images/default/ico_copy.gif"); background-attachment: initial; background-color: inherit; background-size: initial; background-origin: initial; background-clip: initial; background-position: left top; background-repeat: no-repeat;">c</a></span>
c.統一操作處理,例如設置是否可點,屬性等
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<span style="font-family:SimSun;">ButterKnife.apply(nameViews, DISABLE);
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ButterKnife.apply(nameViews, ENABLED, false);</span><span style="font-family:Arial;font-size: 14px;"> </span>
8)可選綁定:默認情況下,“綁定”和“監聽”綁定都是必需的。如果不能找到目標視圖,則將拋出異常。所以做空處理
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<span style="font-family:SimSun;">@Nullable @Bind(R.id.might_not_be_there) TextView mightNotBeThere;
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@Nullable @OnClick(R.id.maybe_missing) void onMaybeMissingClicked() {
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} </span>
三、代碼混淆
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<span style="font-family:SimSun;font-size:14px;">-keep class butterknife.** { *; }
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-dontwarn butterknife.internal.**
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-keep class **$$ViewBinder { *; }
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-keepclasseswithmembernames class * {
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@butterknife.* <fields>;
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}
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-keepclasseswithmembernames class * {
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@butterknife.* <methods>;
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} </span>
四、Zelezny插件的使用
在AndroidStudio->File->Settings->Plugins->搜索Zelezny下載添加就行 ,可以快速生成對應組件的實例對象,不用手動寫。使用時,在要導入註解的Activity 或 Fragment 或 ViewHolder的layout資源代碼上,右鍵——>Generate——Generate ButterKnife Injections,然後就出現如圖的選擇框。(此動態圖來自官網)