如何将值从适配器传递到活动在oncreate方法中我正在获取值bt我希望在create方法中声明该值

如何解决如何将值从适配器传递到活动在oncreate方法中我正在获取值bt我希望在create方法中声明该值

mainActivity

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_product_details);

    long ProductId = Long.parseLong(i.getStringExtra("product_id"));
    long CustomerId = 1;
    int sizeId = 1; // this is where i need int value to be passed
    int quantity = 201;
}

//here i am getting this id value successfully bt i want that value to be assigned to sideId int in on create method
@Override
public void onClickCheckBox(Integer id) {
    Log.d(TAG,String.valueOf(id));
}

界面

public interface OnSizeClickInterface {
 void onClickCheckBox(Integer id);
}

适配器

@Override
public void onBindViewHolder(@NonNull ViewHolder holder,int position) {
    holder.checkBox.setText(pList.get(position).getCode());
    holder.checkBox.setonClickListener(view -> onSizeClickInterface.onClickCheckBox(pList.get(position).getId()));

}

这就是我传递价值的地方，一切正常！正如我提到的那样，我希望该id值可以在create方法中使用 我希望我能尽快得到答案！ 谢谢

解决方法

接口可以通过两种方式实现，一种是已经实现的方式，另一种是要在特定方法内使用的方式。

您必须更改代码。

public int sizeId;// Either initialize sizeId=1
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_product_details);

    long ProductId = Long.parseLong(i.getStringExtra("product_id"));
    long CustomerId = 1;

    int quantity = 201;

    productSizeAdapter = new ProductSizeAdapter(this,pList,new OnSizeClickInterface() {
        @Override
        public void onClickCheckbox(int id) {
            sizeId = id;//this is where i am getting perfect value 
            //You should use sizeId here because it is click event.
            SizeQuantity sizeQuantity = new SizeQuantity(sizeId,quantity); 

        }
    });
    //If you want to use here than you have to initialized sizeId=1. But I don't think you want to use here,because it will be called only once not every time when clicked
    //SizeQuantity sizeQuantity = new SizeQuantity(sizeId,quantity); 

}

,

将sizeId设置为全局变量，并在MainActivity的onClickCheckbox ()中分配新值，然后您就可以从那里继续执行任务，例如更新视图。

MainActivity

private int sizeId = 1;

@Override
public void onClickCheckbox(Integer id) {
    Log.d(TAG,String.valueOf(id));
    sizeId = id;
    // update views if required 
    // Perform any other tasks if required
}