butterknife 基本使用

butterknife 9.0接入

常规项目（非library）接入：

在app的build.gradle引用butterknife：

implementation 'com.jakewharton:butterknife:9.0.0'
annotationProcessor 'com.jakewharton:butterknife-compiler:9.0.0'

library项目接入：

1.在项目根目录build.grdle添加：

buildscript {
    repositories {
        ...
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.2.1'
        classpath 'com.jakewharton:butterknife-gradle-plugin:9.0.0'
    }
}

2.在library的build.gradle添加：

apply plugin: 'com.android.library'
apply plugin: 'com.jakewharton.butterknife'
...

dependencies {
    ...
    implementation 'com.jakewharton:butterknife:9.0.0'
    annotationProcessor 'com.jakewharton:butterknife-compiler:9.0.0'
}

butterknife基本用法：

1.绑定View

    @BindView(R.id.tv_test1)
    TextView tvTest1;

2.绑定多个View

    @BindViews({R.id.tv_test2, R.id.tv_test2})
    public List<TextView> textList;

3.绑定string

    @BindString(R.string.base_bind_string)
    String str;

4.绑定Bitmap

    @BindBitmap(R.drawable.ic_launcher)
    public Bitmap mBitmap ;   

5.绑定颜色

    @BindColor(R.color.base_bind_color)
    int color;

6.绑定点击事件

    @OnClick(R2.id.btn_test1)
    public void showToast(){
        ...
    }

7.绑定长按事件

    @OnLongClick(R2.id.btn_test1)
    public boolean showToastl(){
        ...
        return true;
    }

在Activity中使用：

public class BaseActivity extends AppCompatActivity {

    ...

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

在activity使用注意事项： 1.activity中调用ButterKnife.bind(this)必须在setContentView之后，且不需要做解绑操作 2.使用ButterKnife修饰的元素（例如@BindView修饰)访问控制权限不能是static或者private

在Fragment中使用：

public class BaseFragment extends Fragment {

    private Unbinder unbinder;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View contentView = onCreateViewEx(inflater, container, savedInstanceState);
        unbinder = ButterKnife.bind(this, contentView);
        return contentView;
    }

    /**
     * onDestroyView中进行解绑操作
     */
    @Override
    public void onDestroyView() {
        super.onDestroyView();
        if(unbinder != null) {
            unbinder.unbind();
            unbinder = null;
        }
    }
}

在Fragment使用注意事项： 1.在fragment中使用ButterKnife.bind(this，view)绑定，this不能替换成getActivity() 2.在fragment中使用ButterKnife需要进行解绑操作，一般在onDestroyView调用unbind()方法

ViewHolder使用

    public static class ViewHolder extends RecyclerView.ViewHolder{

        @BindView(R2.id.tv_item)
        public TextView mTextView;

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

注意问题：

1.绑定多个控件@BindViews里面不能有重复ID，否则报错：

错误: @BindViews annotation contains duplicate ID 2131165346. (com.cold.butterknifedemo.BaseActivity.textList)

2.长按事件处理方法需要有返回值，否则报错：

错误: @OnLongClick methods must have a 'boolean' return type. (com.cold.butterknifedemo.BaseActivity.showToastl)

3.在有继承层级的类中使用butterknife，如果使用的类都在同一个模块里，则直接使用就可以了，如果不在同一个library中，会导致

生成的ViewBinding不会调用父类的ViewBinding，解决方法是在子类动态调用父类ViewBiding的构造函数。 JakeWharton/butterknife#808

报错及异常解决：

错误1：

Could not resolve all files for configuration ':app:debugRuntimeClasspath'.

Failed to transform file 'classes.jar' to match attributes {artifactType=android-dex, dexing-is-debuggable=true, dexing-min-sdk=15} using transform DexingTransform Error while dexing. butterknife 9.0.0 使用了 java 8 在app的builid.gradle文件添加：

android {
    ...
    compileOptions {
        sourceCompatibility 1.8
        targetCompatibility 1.8
    }
    ...
}

弹出警告：

WARNING: API 'variantOutput.getProcessResources()' is obsolete and has been replaced with 'variantOutput.getProcessResourcesProvider()'. It will be removed at the end of 2019. For more information, see https://d.android.com/r/tools/task-configuration-avoidance. To determine what is calling variantOutput.getProcessResources(), use -Pandroid.debug.obsoleteApi=true on the command line to display a stack trace. Affected Modules: module1 这是gradle-4.10.1-all的一个bug，使用gradle-4.6-all即可 解决方案： gradle插件使用3.2.1，在根目录build.gradle

    dependencies {
        classpath 'com.android.tools.build:gradle:3.2.1'
        ...
    }
    ```
gradle-wrapper.properties修改：
```Groovy
...
distributionUrl=https\://services.gradle.org/distributions/gradle-4.6-all.zip

错误3：

在我的项目中集成了databinding，导致butterknife使用不当报错会只想databinding，给排查异常带来了很大的困扰。 例如，变量使用private, static修饰,变量类型和获取的实际类型不对应等。

license

Copyright 2019 wjianchen13

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.