自定义加减器

public class AddView extends LinearLayout implements View.OnClickListener {
private TextView mRemvoe,mNumber,mAdd;

public AddView(Context context, AttributeSet attrs) {
    super(context, attrs);
    LayoutInflater.from(context).inflate(R.layout.add_item,this);
    initView();
}
public void setNumber(int number){
    mNumber.setText(number+"");
}

//找控件
private void initView() {
  mRemvoe=findViewById(R.id.remove);
  mNumber=findViewById(R.id.number);
  mAdd=findViewById(R.id.add);
  mRemvoe.setOnClickListener(this);
  mAdd.setOnClickListener(this);
}

@Override
public void onClick(View v) {
    int number = Integer.parseInt(mNumber.getText().toString());
    switch (v.getId()){
        case R.id.remove:
            if (number>1){
                number--;
                if (callBack!=null){
                    callBack.setCount(number);
                }
            }else {
                Toast.makeText(getContext(), "商品数量最少为1", Toast.LENGTH_SHORT).show();
            }
            break;
        case R.id.add:
            number++;
            if (callBack!=null){
                callBack.setCount(number);
            }
            break;
    }

}

//接口回调改变count
public AddCallBack callBack;

public void setCallBack(AddCallBack back){
    callBack=back;
}

public interface AddCallBack{
    void  setCount(int number);
}

}