butterknife编译成功，运行成功，找控件的时候为空

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