Android中ButterKnife(黃油刀)的詳細使用
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:該文件使用7.0版本,8.0版本方法名有所改動,建議看官方文件,整體業務邏輯和原理沒什麼變動。
在android程式設計過程中,我們會寫大量的佈局和點選事件,像初始view、設定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,而網上的文件和例子都過時了,7.0之後的版本改動很大,之前的註解都不能用了,所以借鑑官方文件總結了一下,接下來就介紹一下如何使用。基本參照官方文件,加上自己的心得。
ButterKnife 優勢:
1.強大的View繫結和Click事件處理功能,簡化程式碼,提升開發效率
2.方便的處理Adapter裡的ViewHolder繫結問題
3.執行時不會影響APP效率,使用配置方便
4.程式碼清晰,可讀性強
使用心得:
1.Activity ButterKnife.bind(this);必須在setContentView();之後,且父類bind繫結後,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.匯入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 搜尋butterknife即可,第一個就是
3)當然也可以用maven和gradle配置
<span style="font-family:SimSun;font-size:14px;">MAVEN <dependency> <groupId>com.jakewharton</groupId> <artifactId>butterknife</artifactId> <version>(insert latest version)</version> </dependency> GRADLE compile 'com.jakewharton:butterknife:(insert latest version)' Be sure to suppress this lint warning in your build.gradle.(關閉) lintOptions { disable 'InvalidPackage' } </span>
注意如果在Library 專案中使用要按如下步驟(github中有具體描述)否則無法找到view:
二.常見使用方法:
1)由於每次都要在Activity中的onCreate繫結Activity,所以個人建議寫一個BaseActivity完成繫結,子類繼承即可
注:ButterKnife.bind(this);繫結Activity 必須在setContentView之後:
實現如下(FragmentActivity 實現一樣):
<span style="font-family:SimSun;font-size:14px;">public abstract class BaseActivity extends Activity {
public abstract int getContentViewId();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(getContentViewId());
ButterKnife.bind(this);
initAllMembersView(savedInstanceState);
}
protected abstract void initAllMembersView(Bundle savedInstanceState);
@Override
protected void onDestroy() {
super.onDestroy();
ButterKnife.unbind(this);//解除繫結,官方文件只對fragment做了解綁
}
} </span>
2)繫結fragment
<span style="font-family:SimSun;font-size:14px;">public abstract class BaseFragment extends Fragment {
public abstract int getContentViewId();
protected Context context;
protected View mRootView;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
mRootView =inflater.inflate(getContentViewId(),container,false);
ButterKnife.bind(this,mRootView);//繫結framgent
this.context = getActivity();
initAllMembersView(savedInstanceState);
return mRootView;
}
protected abstract void initAllMembersView(Bundle savedInstanceState);
@Override
public void onDestroyView() {
super.onDestroyView();
ButterKnife.unbind(this);//解綁
}
} </span>
3)繫結view
<span style="font-family:SimSun;font-size:14px;">@Bind(R.id.hello_world)
TextView mHelloWorldTextView;
@Bind(R.id.app_name)
TextView mAppNameTextView;//view</span>
4)繫結資源
<span style="font-family:SimSun;font-size:14px;">@BindString(R.string.app_name)
String appName;//sting
@BindColor(R.color.red)
int textColor;//顏色
@BindDrawable(R.mipmap.ic_launcher)
Drawable drawable;//drawble
@Bind(R.id.imageview)
ImageView mImageView;
@Bind(R.id.checkbox)
CheckBox mCheckBox;
@BindDrawable(R.drawable.selector_image)
Drawable selector; </span>
5)Adapter ViewHolder 繫結
<span style="font-family:SimSun;font-size:14px;">public class TestAdapter extends BaseAdapter {
private List<String> list;
private Context context;
public TestAdapter(Context context, List<String> list) {
this.list = list;
this.context = context;
}
@Override
public int getCount() {
return list==null ? 0 : list.size();
}
@Override
public Object getItem(int position) {
return list.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = LayoutInflater.from(context).inflate(R.layout.layout_list_item, null);
holder = new ViewHolder(convertView);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.textview.setText("item=====" + position);
return convertView;
}
static class ViewHolder {
@Bind(R.id.hello_world)
TextView textview;
public ViewHolder(View view) {
ButterKnife.bind(this, view);
}
}
} </span>
6)點選事件的繫結:不用宣告view,不用setOnClickLisener()就可以繫結點選事件
a.直接繫結一個方法
<span style="font-family:SimSun;font-size:14px;">@OnClick(R.id.submit)
public void submit(View view) {
// TODO submit data to server...
} </span>
b.所有監聽方法的引數是可選的
<span style="font-family:SimSun;font-size:14px;">@OnClick(R.id.submit)
public void submit() {
// TODO submit data to server...
} </span>
c.定義一個特定型別,它將自動被轉換
<span style="font-family:SimSun;font-size:14px;">@OnClick(R.id.submit)
public void sayHi(Button button) {
button.setText("Hello!");
}</span>
d.多個view統一處理同一個點選事件,很方便,避免抽方法重複呼叫的麻煩
<span style="font-family:SimSun;font-size:14px;">@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();
}
} </span>
e.自定義view可以繫結自己的監聽,不指定id
<span style="font-family:SimSun;font-size:14px;">public class FancyButton extends Button {
@OnClick
public void onClick() {
// TODO do something!
}
} </span>
f.給EditText加addTextChangedListener(即新增多回調方法的監聽的使用方法),利用指定回撥,實現想回調的方法即可,哪個註解不會用點進去看下原始碼上的註釋就會用了
<span style="font-family:SimSun;font-size:14px;">@OnTextChanged(value = R.id.mobileEditText, callback = OnTextChanged.Callback.BEFORE_TEXT_CHANGED)
void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@OnTextChanged(value = R.id.mobileEditText, callback = OnTextChanged.Callback.TEXT_CHANGED)
void onTextChanged(CharSequence s, int start, int before, int count) {
}
@OnTextChanged(value = R.id.mobileEditText, callback = OnTextChanged.Callback.AFTER_TEXT_CHANGED)
void afterTextChanged(Editable s) {
} </span>
7)對一組View進行統一操作
a.裝入一個list
<span style="font-family:SimSun;font-size:14px;">@Bind({ R.id.first_name, R.id.middle_name, R.id.last_name })
List<EditText> nameViews; </span>
b.設定統一處理
<span style="font-family:SimSun;">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);
}
};<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,例如設定是否可點,屬性等
<span style="font-family:SimSun;">ButterKnife.apply(nameViews, DISABLE);
ButterKnife.apply(nameViews, ENABLED, false);</span><span style="font-family:Arial;font-size: 14px;"> </span>
8)可選繫結:預設情況下,“繫結”和“監聽”繫結都是必需的。如果不能找到目標檢視,則將丟擲異常。所以做空處理
<span style="font-family:SimSun;">@Nullable @Bind(R.id.might_not_be_there) TextView mightNotBeThere;
@Nullable @OnClick(R.id.maybe_missing) void onMaybeMissingClicked() {
// TODO ...
} </span>
三、程式碼混淆
<span style="font-family:SimSun;font-size:14px;">-keep class butterknife.** { *; }
-dontwarn butterknife.internal.**
-keep class **$$ViewBinder { *; }
-keepclasseswithmembernames class * {
@butterknife.* <fields>;
}
-keepclasseswithmembernames class * {
@butterknife.* <methods>;
} </span>
四、Zelezny外掛的使用
在AndroidStudio->File->Settings->Plugins->搜尋Zelezny下載新增就行 ,可以快速生成對應元件的例項物件,不用手動寫。使用時,在要匯入註解的Activity 或 Fragment 或 ViewHolder的layout資原始碼上,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)