加减器(自定义view)

1.布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal">
<ImageView
    android:layout_width="40dp"
    android:layout_height="40dp"
    android:src="@drawable/add"
    android:id="@+id/img_up"/>
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="30dp"
        android:id="@+id/num"
        android:text="1"/>
    <ImageView
        android:layout_width="40dp"
        android:layout_height="40dp"
        android:src="@drawable/down"
        android:id="@+id/img_down"/>
</LinearLayout>

2.新建class类

package com.example.recycler;

import android.content.Context;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

/**
 * author:Created by MaYue on 2017/11/21.
 */

public class AddAndDownview extends LinearLayout {

    private TextView count;

    public AddAndDownview(Context context) {
        this(context,null);
    }

    public AddAndDownview(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs,0);
    }

    public AddAndDownview(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context);
    }
    private OnAddDeleteClickListener listener;

    //对外提供一个点击的回调接口
    public interface OnAddDeleteClickListener{
        void onAddClick(View v);
        void onDelClick(View v);
    }

    public void setOnAddDeleteClick(OnAddDeleteClickListener listener){
        this.listener = listener;
    }

    private void init(Context content) {
        View view = View.inflate(content, R.layout.addview, this);
        ImageView up = (ImageView) view.findViewById(R.id.img_up);
        ImageView down = (ImageView) view.findViewById(R.id.img_down);
        count = (TextView) view.findViewById(R.id.num);

        up.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View view) {
                listener.onAddClick(view);
            }
        });

        down.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View view) {
                listener.onDelClick(view);
            }
        });
    }

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

    public int getCount(){
        int number=Integer.parseInt(count.getText().toString().trim());
        return number;
    }
}