Android Butterknife空对象引用错误

Question

我在Android ButterKnife中出现错误，使用androidx而不是Android

java.lang.NullPointerException：尝试在null对象引用上调用虚拟方法"void androidx.recyclerview.widget.RyclerView.setLayoutManager(androidx.recyclerview.vidget.recyclerview$LayoutManager("> build.gradle(项目(

classpath 'com.android.tools.build:gradle:3.2.1'

build.gradle(应用程序(

implementation 'com.jakewharton:butterknife:8.8.1'
annotationProcessor 'com.jakewharton:butterknife-compiler:8.8.1'

和片段中的错误

@BindView(R.id.recyclerViewProduct)
RecyclerView recyclerViewProduct;
private Unbinder unbinder;

充气视图

View view = inflater.inflate(R.layout.fragment_product, container, false);
unbinder = ButterKnife.bind(this, view);

此处出现错误

recyclerViewProduct.setLayoutManager(mLayoutManager);

我解除了的绑定

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

Answer 1

如果 R.id.recyclerViewProduct 在布局文件fragment_product.xml中定义。

Answer 2

用这个替换Butterknifer库

implementation 'com.jakewharton:butterknife:9.0.0-rc1'
annotationProcessor 'com.jakewharton:butterknife-compiler:9.0.0-rc1'
kapt 'com.jakewharton:butterknife-compiler:9.0.0-rc1'