Activity类
里面写向适配器里面传入你的CheckBox
private RecyView adapter=new RecyView();

 adapter.setCheckBox(quanxuan);

适配器
写一个方法来接受Activity穿的CheckBox

private CheckBox checkBox;

public  void  setCheckBox(final CheckBox checkBox){
     this.checkBox=checkBox;
     checkBox.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
             CheckBox checkBox1= (CheckBox) v;
             boolean checked = checkBox1.isChecked();
             selectAll(checked);
         }
     });
}

在适配器的onBindViewHolder展示
viewHolder.checkboxx.setChecked(list.get(i).isIschecked());

private void selectAll(boolean checked){
    for (int i = 0; i <list.size() ; i++) {
        Bean.ResultBean resultBean = list.get(i);
        resultBean.setIschecked(checked);
    }
    notifyDataSetChanged();

}