简单的加减器

package com.example.shoppingcart.view.activity;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

import com.example.shoppingcart.R;

public class AddAndRemove extends LinearLayout implements View.OnClickListener {

    private View view;
    private TextView subtractor;
    private TextView number;
    private TextView add;
    private int count = 1;

    public AddAndRemove(Context context) {
        super(context);
    }

    public AddAndRemove(Context context, AttributeSet attrs) {
        super(context, attrs);
        view = View.inflate(context, R.layout.addandremove, this);
        initView();
    }

    private void initView() {
        subtractor = (TextView) view.findViewById(R.id.subtractor);
        number = (TextView) view.findViewById(R.id.number);
        add = (TextView) view.findViewById(R.id.add);

        subtractor.setOnClickListener(this);
        add.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.subtractor:
                if (count>1){
                    count--;
                    number.setText(count+"");

　　　　　　　　　　//点击改变之后，用接口回调传值

                    if (onNumberChangeListener!=null){
                        onNumberChangeListener.changed(count);
                    }
                }else {
                    Toast.makeText(getContext(), "不能再少了呢", Toast.LENGTH_SHORT).show();
                }
                break;
            case R.id.add:

                count++;
                number.setText(count+"");
　　　　　　　　　　//点击改变之后，用接口回调传值
                if (onNumberChangeListener != null){
                    onNumberChangeListener.changed(count);
                }

                break;
        }
    }

    public interface OnNumberChangeListener{
        void changed(int num);
    }

    OnNumberChangeListener onNumberChangeListener;

    public void setOnNumberChangeListener(OnNumberChangeListener onNumberChangeListener){
        this.onNumberChangeListener = onNumberChangeListener;
    }

    public int getNumber(){
        return count;
    }

    public void setCount(int num){
        count = num;
        number.setText(count+"");
    }

}