Android butterknife学习总结

1. 什么是ButterKnife？

ButterKnife是一个专注于Android系统View、Resource、Action的注入框架,可以减少大量的findViewById以及setOnClickListener代码，并且可以利用一个叫做Zelezny的插件，可视化一键生成。

妈妈再也不用担心我敲代码敲到手抽筋儿了~

2. 在android studio中配置ButterKnife

1) 在project的build.gradle中添加：

classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'

添加后示例如下：

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.2.2'
        classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

2) 在app的build.gradle中添加：

apply plugin: 'android-apt'

compile 'com.jakewharton:butterknife:8.4.0'
apt 'com.jakewharton:butterknife-compiler:8.4.0'

添加后示例如下：

apply plugin: 'com.android.application'
apply plugin: 'android-apt'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.2"
    defaultConfig {
        applicationId "fxjzzyo.com.butterknifetestdemo"
        minSdkVersion 14
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:25.3.1'
    testCompile 'junit:junit:4.12'
    compile 'com.jakewharton:butterknife:8.4.0'
    apt 'com.jakewharton:butterknife-compiler:8.4.0'
}

3. 如何使用ButterKnife？

注：以下的所有操作都要在绑定了当前Activity（ ButterKnife.bind(this);）的前提下才能进行！

1）绑定view @BindView(R.id.xxx)

package fxjzzyo.com.butterknifetestdemo;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;

import butterknife.BindView;
import butterknife.ButterKnife;

public class MainActivity extends AppCompatActivity {
    //绑定
    @BindView(R.id.tv_hello)
    TextView tvHello;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //首先要绑定activity！！！
        ButterKnife.bind(this);
        //使用绑定后的view
        tvHello.setText("hahahahahah");
    }

}

2）绑定views @BindViews({ R.id.button1 , R.id.button2 , R.id.button3 })

//绑定
@BindViews({ R.id.button1  , R.id.button2 ,  R.id.button3 })
public List<Button> buttonList ;

3）绑定点击事件@OnClick( )

@OnClick(R.id.button1 )   //给 button1 设置一个点击事件
public void showToast(){
Toast.makeText(this, "is a click",Toast.LENGTH_SHORT).show();
}

4）绑定长按点击事件@OnLongClick( )

@OnLongClick( R.id.button1 )    //给 button1 设置一个长按事件
public boolean showToast2(){
Toast.makeText(this, "is a long click", Toast.LENGTH_SHORT).show();
return true  ;
}

5）多个控件绑定同一个事件

/**
 * 两个不同的button都相应onButterKnifeBtnClick事件回调
 * @param button
 */
    @OnClick({R.id.btn_butter_knife, R.id.btn_butter_knife1})
    public void onButterKnifeBtnClick(Button button) {
        Log.i(TAG, "onButterKnifeBtnClick");
    }

自定义的控件不通过ID也可以绑定到自己的事件

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

6）多事件回调比如EditText添加addTextChangedListener，使用前：

editText.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {

            }

            @Override
            public void afterTextChanged(Editable s) {

            }
        });

使用后：

@OnTextChanged(value = R.id.nameEditText, callback = OnTextChanged.Callback.BEFORE_TEXT_CHANGED)
    void beforeTextChanged(CharSequence s, int start, int count, int after) {

    }
    @OnTextChanged(value = R.id.nameEditText, callback = OnTextChanged.Callback.TEXT_CHANGED)
    void onTextChanged(CharSequence s, int start, int before, int count) {

    }
    @OnTextChanged(value = R.id.nameEditText, callback = OnTextChanged.Callback.AFTER_TEXT_CHANGED)
    void afterTextChanged(Editable s) {

    }

7）绑定资源文件

	//绑定string字符串
    @BindString(R.string.title_btn_butter_knife)
    String butterKnifeStr;
    //绑定Drawable图片
    @BindDrawable(R.mipmap.ic_launcher)
    Drawable butterKnifeDrawable;
    //绑定Bitmap图片
    @BindBitmap(R.mipmap.ic_launcher)
    Bitmap  butterKnifeBitmap;
    //绑定数组
    @BindArray(R.array.day_of_week)
    String weeks[];
    //绑定color颜色
    @BindColor(R.color.colorPrimary)
    int colorPrimary;
    //绑定Dimen尺寸
    @BindDimen(R.dimen.activity_horizontal_margin)
    Float spacer;

8）在Fragment中使用

由于不同的视图生命周期，所以需要在onCreateView中 bind，在onDestroyView中 unbind

public class MyFragment extends Fragment {
  @BindView(R.id.button1) Button button1;
  @BindView(R.id.button2) Button button2;
  private Unbinder unbinder;

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

  @Override public void onDestroyView() {
    super.onDestroyView();
    //解绑
    unbinder.unbind();
  }
}

9）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.mylayout, parent, false);
      holder = new ViewHolder(view);
      view.setTag(holder);
    }
    holder.name.setText("fxjzzyo");
    return view;
  }

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

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

10）ButterKnife.findById() ButterKnife 也提供了findById函数，通过findById()可以获取Activity、Dialog、View中的view，并且是泛型类型不需要强转。

View view =LayoutInflater.from(context).inflate(R.layout.layout, 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);

4. ButterKnife自动生成插件Zelezny安装

在android studio的setting中，如下图：

这里写图片描述安装后，会提示重启android studio，重启即可接下来就能自动生成绑定了~~ 就是这么让你一懒再懒~~ 生成方法：将光标放到Activity、Fragment、或ViewHolder中的资源文件上，右键—>Generate—Generate ButterKnife Injections 大概如下图：