ButterKnife(一): 使用篇

butterknife官方地址

项目集成

在app module的build.gradle文件下添加如下依赖

android {
  ...
  // Butterknife requires Java 8.
  compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
  }
}

dependencies {
  implementation 'com.jakewharton:butterknife:10.2.1'
  annotationProcessor 'com.jakewharton:butterknife-compiler:10.2.1'
  //kapt 'com.jakewharton:butterknife-compiler:10.2.1'  //Kotlin
}

插件导入

AndroidStudio-->setting-->pluign: 搜索并安装
android-butterknife-zelezny

自定义全局变量前缀

插件安装后,在AS-->setting-->Other Settings-->ButterknifeZelezny中,有2个输入框,可修改前缀和viewHoder的名称

prefix.png

使用

1. activity中的使用

 @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(bindLayoutID());
        mBind = ButterKnife.bind(this);
        initView(savedInstanceState);
    }

@Override
    protected void onDestroy() {
        super.onDestroy();
        if (mBind != null && mBind != Unbinder.EMPTY) {
            mBind.unbind();
            mBind = null;
        }
    }

 @Override
    protected int bindLayoutID() {
        return R.layout.activity_main;
    }

鼠标停留在R.layout.activity_main然后按快捷键alt+insert选择生成butterknife injections, 完成控件的绑定.

2. 绑定资源

@BindBool, @BindColor, @BindDimen, @BindDrawable, @BindInt, @BindString等注解可以绑定资源作为全局变量使用
参考 ButterKnife支持的所有注解

  @BindString(R.string.title) String title;
  @BindDrawable(R.drawable.graphic) Drawable graphic;
  @BindColor(R.color.red) int red; // int or ColorStateList field
  @BindDimen(R.dimen.spacer) float spacer; // int (for pixel size) or float (for exact value) field

3.非Activity中使用

3.1 在Fragment中使用

public class FancyFragment 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);
    unbinder = ButterKnife.bind(this, view);
    // TODO Use fields...
    return view;
  }

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

3.2在adapter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.whatever, parent, false);
      holder = new ViewHolder(view);
      view.setTag(holder);
    }

    holder.name.setText("John Doe");
    // etc...

    return view;
  }

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

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

4 绑定多组件

@BindViews({ R.id.first_name, R.id.middle_name, R.id.last_name })
List nameViews;

5 绑定控件的点击事件

    @OnClick(R.id.button)
    public void onClick(Button button) {
        ToastUtils.showShort(R.string.click);
        button.setText(R.string.click);
    }

//无参数点击
   @OnClick(R.id.button)
    public void onClick( ) {
        ToastUtils.showShort(R.string.click);
    }

//参数为View
   @OnClick(R.id.button)
    public void onClick(View view ) {
        ToastUtils.showShort(R.string.click);
    
    }

点击函数里面的参数可以是具体的某个控件,也可以不带参数, 另外ButterKnife的点击事件是防抖动的,可以有效避免短时间内多次点击.有兴趣的可以参看底部源码解析篇

6 空绑定

//@Nullable用于全局变量
@Nullable @BindView(R.id.might_not_be_there) TextView mightNotBeThere;
//@Optional 用于方法
@Optional @OnClick(R.id.maybe_missing) void onMaybeMissingClicked() {
  // TODO ...
}

我的ButterKnife相关文章

ButterKnife(一): 使用篇
ButterKnife(二): 原理解析篇
ButterKnife(三): ButterKnifeProcessor解析