安卓开发懒鬼最爱之ButterKnife，依赖注入第三方是库，进一步加速开发速度

Posted 2020-09-28 cxchanpin

转载请注明出处：王亟亟的大牛之路

还在烦躁一大堆findById的控件操作而烦恼么？

平时，我们的那一系列findById是一个“浩大的project”样比例如以下

这是以前一个项目的一个填童虎数据表单的一个Activity，这是一系列的声明

public class UserInfoActivity extends Activity implements OnClickListener {
    TextView userNameTxt;
    RelativeLayout sexLayout;
    TextView sexTxt;
    RelativeLayout birthdayLayout;
    TextView birthdayTxt;
    RelativeLayout provinceLayout;
    TextView provinceTxt;
    RelativeLayout cityLayout;
    TextView cityTxt;
    RelativeLayout hasCarCardLayout;
    TextView hasCarCardTxt;
    RelativeLayout hasCarLayout;
    TextView hasCarTxt;
    RelativeLayout buyCarTimeLayout;
    TextView buyCarTimeTxt;
    RelativeLayout carBrandLayout;
    TextView carBrandTxt;
    RelativeLayout carTypeLayout;
    TextView carTypeTxt;
    RelativeLayout carPriceLayout;
    TextView carPriceTxt;
    RelativeLayout carCardNumLayout;
    TextView carCardNumTxt;
    RelativeLayout carNumLayout;
    TextView carNumTxt;
    RelativeLayout familyIncomeLayout;
    TextView familyIncomeTxt;
    RelativeLayout carCarImgLayout;
    ImageView carCarImg;
    RelativeLayout drivingLicenseLayout;
    ImageView drivingLicenseImg;
    LinearLayout backLin;
    LinearLayout saveBtn;

    RelativeLayout userNameLayout;
    LinearLayout sexLinLayout;
    LinearLayout birthdayLinLayout;
    LinearLayout provinceLinLayout;
    LinearLayout cityLinLayout;
    LinearLayout carCarLinLayout;
    LinearLayout hasCarLinLayout;
    LinearLayout buyCarTimeLinLayout;
    LinearLayout carBrandLinLayout;
    LinearLayout carTypeLinLayout;
    LinearLayout carPriceLinLayout;
    LinearLayout carCardNumLinLayout;
    LinearLayout carNumLinLayout;
    LinearLayout familiIncomeLinLayout;
    LinearLayout carCardImageLinLayout;
    LinearLayout drivindLicenseLinLayout;
    LinearLayout professionLinLayout;
    LinearLayout carInfoLayout;
    TextView professionTv;

这是一大堆的findById

    backLin = (LinearLayout) titleView.findViewById(R.id.backLin);
        saveBtn = (LinearLayout) titleView.findViewById(R.id.saveBtn);
        userNameLayout = (RelativeLayout) contentView
                .findViewById(R.id.userNameLayout);
        userNameTxt = (TextView) contentView.findViewById(R.id.userNameTxt);
        sexLayout = (RelativeLayout) contentView.findViewById(R.id.sexLayout);
        sexTxt = (TextView) contentView.findViewById(R.id.sexTxt);
        birthdayLayout = (RelativeLayout) contentView
                .findViewById(R.id.birthdayLayout);
        birthdayTxt = (TextView) contentView.findViewById(R.id.birthdayTxt);
        provinceLayout = (RelativeLayout) contentView
                .findViewById(R.id.provinceLayout);
        provinceTxt = (TextView) contentView.findViewById(R.id.provinceTxt);
        cityLayout = (RelativeLayout) contentView.findViewById(R.id.cityLayout);
        cityTxt = (TextView) contentView.findViewById(R.id.cityTxt);
        hasCarCardLayout = (RelativeLayout) contentView
                .findViewById(R.id.carCardLayout);
        hasCarCardTxt = (TextView) contentView.findViewById(R.id.carCardTxt);
        hasCarLayout = (RelativeLayout) contentView
                .findViewById(R.id.hasCarLayout);
        hasCarTxt = (TextView) contentView.findViewById(R.id.hasCarTxt);
        buyCarTimeLayout = (RelativeLayout) contentView
                .findViewById(R.id.buyCarTimeLayout);
        buyCarTimeTxt = (TextView) contentView.findViewById(R.id.buyCarTimeTxt);
        carBrandLayout = (RelativeLayout) contentView
                .findViewById(R.id.carBrandLayout);
        carBrandTxt = (TextView) contentView.findViewById(R.id.carBrandTxt);
        carTypeLayout = (RelativeLayout) contentView
                .findViewById(R.id.carTypeLayout);
        carTypeTxt = (TextView) contentView.findViewById(R.id.carTypeTxt);
        carPriceLayout = (RelativeLayout) contentView
                .findViewById(R.id.carPriceLayout);
        carPriceTxt = (TextView) contentView.findViewById(R.id.carPriceTxt);
        carCardNumLayout = (RelativeLayout) contentView
                .findViewById(R.id.carCardNumLayout);
        carCardNumTxt = (TextView) contentView.findViewById(R.id.carCardNumTxt);
        carNumLayout = (RelativeLayout) contentView
                .findViewById(R.id.carNumLayout);
        carNumTxt = (TextView) contentView.findViewById(R.id.carNumTxt);
        familyIncomeLayout = (RelativeLayout) contentView
                .findViewById(R.id.familyIncomeLayout);
        familyIncomeTxt = (TextView) contentView
                .findViewById(R.id.familyIncomeTxt);
        carCarImgLayout = (RelativeLayout) contentView
                .findViewById(R.id.carCarImgLayout);
        carCarImg = (ImageView) contentView.findViewById(R.id.carCarImg);
        drivingLicenseLayout = (RelativeLayout) contentView
                .findViewById(R.id.drivingLicenseLayout);
        drivingLicenseImg = (ImageView) contentView
                .findViewById(R.id.drivingLicenseImg);

        sexLinLayout = (LinearLayout) contentView
                .findViewById(R.id.sexLinLayout);
        birthdayLinLayout = (LinearLayout) contentView
                .findViewById(R.id.birthdayLinLayout);
        provinceLinLayout = (LinearLayout) contentView
                .findViewById(R.id.provinceLinLayout);
        cityLinLayout = (LinearLayout) contentView
                .findViewById(R.id.cityLinLayout);
        carCarLinLayout = (LinearLayout) contentView
                .findViewById(R.id.carCarLinLayout);
        hasCarLinLayout = (LinearLayout) contentView
                .findViewById(R.id.hasCarLinLayout);
        buyCarTimeLinLayout = (LinearLayout) contentView
                .findViewById(R.id.buyCarTimeLinLayout);
        carBrandLinLayout = (LinearLayout) contentView
                .findViewById(R.id.carBrandLinLayout);
        carTypeLinLayout = (LinearLayout) contentView
                .findViewById(R.id.carTypeLinLayout);
        carPriceLinLayout = (LinearLayout) contentView
                .findViewById(R.id.carPriceLinLayout);
        carCardNumLinLayout = (LinearLayout) contentView
                .findViewById(R.id.carCardNumLinLayout);
        carNumLinLayout = (LinearLayout) contentView
                .findViewById(R.id.carNumLinLayout);
        familiIncomeLinLayout = (LinearLayout) contentView
                .findViewById(R.id.familiIncomeLinLayout);
        drivindLicenseLinLayout = (LinearLayout) contentView
                .findViewById(R.id.drivindLicenseLinLayout);
        carCardImageLinLayout = (LinearLayout) contentView
                .findViewById(R.id.carCardImageLinLayout);
        professionLinLayout = (LinearLayout) contentView
                .findViewById(R.id.professionLinLayout);
        carInfoLayout = (LinearLayout) contentView
                .findViewById(R.id.carInfoLayout);
        professionTv = (TextView) contentView.findViewById(R.id.professionTv);

看着看着蛋都碎了，简直不能忍。所以今天推荐一个简单易用的库，效果如图

不试试非常快非常猛？轻轻点两下，这一大堆玩意都能解决！

来来来，JAR包下载：butterknife-7.0.1
Maven:

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

Gradle:

compile ‘com.jakewharton:butterknife:7.0.1‘

项目包下载地址：点击下载

Gif的功能仅仅能在androidStudio使用，Eclipse的小伙伴仅仅能手打了。。

操作方法：
Android Studio: go to Preferences → Plugins → Browse repositories and search for ButterKnife Zelezny
跟我们用图片做背景图一样，下载一个插件就好。

好。废话不多，開始拆作者的例子（楼主小学英文大致的理解讲述下）：

Annotate fields with @Bind and a view ID for Butter Knife to find and automatically cast the corresponding view in your layout.
凝视字段“绑定”和“ Butter Knife”的视图标识。并自己主动在布局中查看对应的视图。

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...
  }
}

分析：使用 @Bind 就能够对控件进行声明，已经findViewById的操作，然后在onCreate（）方法中调用 ButterKnife.bind(this);使之生效，假设你认为有必要的话能够在onDestory()方法中再调用ButterKnife.unbind(this);进行解绑操作

You can also perform binding on arbitrary objects by supplying your own view root.
能够通过提供您自己的视图根试图来运行随意对象的绑定。我们能够用在fragment等用到inflater的地方。

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;
  }
}

分析：这边与Activity的区别仅仅是在调用的方法中须要传入被绑定的那个根试图而已。

Another use is simplifying the view holder pattern inside of a list adapter.
在ListView或者其它一些用到 ViewHolder形式的地方都能够用

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);
    }
  }
}

You can group multiple views into a List or array
能够把一些控件放进一个集合或者数组中

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

Listeners can also automatically be configured onto methods.
也能够自己主动将侦听器配置为方法。

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

All arguments to the listener method are optional.
全部參数的侦听器方法是可选的。

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

Define a specific type and it will automatically be cast.
定义一个特定类型，它将自己主动被转换。

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

Specify multiple IDs in a single binding for common event handling.
指定多个身ID在一个单一的绑定事件处理。

@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();
  }
}

自己也写了一个Demo大致内容也和范例差点儿相同。只是比較直观，能够看一下
MainActivity

public class MainActivity extends AppCompatActivity implements TestFragment.OnFragmentInteractionListener{
    @Bind(R.id.textView)
    TextView textview;
    @Bind(R.id.button1)
    Button button1;
    @Bind(R.id.button2)
    Button button2;
    @Bind(R.id.button3)
    Button button3;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @OnClick(R.id.button1)
    public void button1click(Button btn){
        btn.setText("BTN1");
    }

    @OnClick({R.id.button1, R.id.button2, R.id.button3 })
    public void click(View v) {
    switch (v.getId()){
        case R.id.button1:
            Toast.makeText(this, "button1", Toast.LENGTH_SHORT).show();
            break;
        case R.id.button2:
            Toast.makeText(this, "button2",Toast.LENGTH_SHORT).show();
            break;
        case R.id.button3:
            Toast.makeText(this, "button3",Toast.LENGTH_SHORT).show();
            break;
    }
    }

    @Override
    public void onFragmentInteraction(Uri uri) {

    }
}

内部的fragment

public class TestFragment extends Fragment {
    // TODO: Rename parameter arguments, choose names that match
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";
    @Bind(R.id.fbtn)
    Button fbtn;
    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;

    private OnFragmentInteractionListener mListener;

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @param param1 Parameter 1.
     * @param param2 Parameter 2.
     * @return A new instance of fragment TestFragment.
     */
    // TODO: Rename and change types and number of parameters
    public static TestFragment newInstance(String param1, String param2) {
        TestFragment fragment = new TestFragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    public TestFragment() {
        // Required empty public constructor
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

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

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

    @OnClick(R.id.fbtn)
    void fbtnClick() {
        Toast.makeText(getActivity(), "Fragment", Toast.LENGTH_SHORT).show();
        fbtn.setText("呵呵哒");
        getView().setBackgroundColor(Color.RED);
    }

    // TODO: Rename method, update argument and hook method into UI event
    public void onButtonPressed(Uri uri) {
        if (mListener != null) {
            mListener.onFragmentInteraction(uri);
        }
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        try {
            mListener = (OnFragmentInteractionListener) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString()
                    + " must implement OnFragmentInteractionListener");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }

    /**
     * This interface must be implemented by activities that contain this
     * fragment to allow an interaction in this fragment to be communicated
     * to the activity and potentially other fragments contained in that
     * activity.
     * <p/>
     * See the Android Training lesson <a href=
     * "http://developer.android.com/training/basics/fragments/communicating.html"
     * >Communicating with Other Fragments</a> for more information.
     */
    public interface OnFragmentInteractionListener {
        // TODO: Update argument type and name
        public void onFragmentInteraction(Uri uri);
    }

}

主Activity的布局

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

    <TextView android:text="@string/hello_world" android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/textView" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="button1"
        android:id="@+id/button1"
        android:layout_below="@+id/textView"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="button2"
        android:id="@+id/button2"
        android:layout_below="@+id/button1"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="button3"
        android:id="@+id/button3"
        android:layout_below="@+id/button2"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />

    <fragment
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:name="test.butterknife.com.testdemo.TestFragment"
        android:id="@+id/fragment"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"
        android:layout_below="@+id/button3"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentBottom="true" />

</RelativeLayout>

大致就是如此，附上源代码地址：http://yunpan.cn/cdPg8bUwJa8sv 訪问password 1845

有意參与一些开源项目。easy上手的Team能够找我聊聊。看看能够造福社会不。哈哈哈