Preface

The use of a simple small control, the code is simple and easy to use

Effect picture

Code example

layout/number_adder.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center">

    <ImageView
        android:id="@+id/btn_reduce"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@mipmap/reduce"
        android:textSize="20sp" />

    <TextView
        android:id="@+id/tv_count"
        android:layout_width="50dp"
        android:layout_height="40dp"
        android:gravity="center"
        android:text="1"
        android:textColor="#000"
        android:textSize="20sp" />

    <ImageView
        android:id="@+id/btn_add"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@mipmap/add"
        android:textSize="20sp" />
</LinearLayout>

Custom view code

package adpickerview.zbxxjl.com.addersubtractor;

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

import butterknife.OnClick;

/**
 * Created by Administrator on 2017/11/20.
 */

public class adderView extends LinearLayout implements View.OnClickListener {


    private int value = 1;
    private int minValue = 1;
    private int maxValue = 10;
    private final TextView tvCount;

    public adderView(Context context, AttributeSet attrs) {
        super(context, attrs);
        View view = View.inflate(context, R.layout.number_adder, this);
        ImageView btn_reduce = (ImageView) view.findViewById(R.id.btn_reduce);
        tvCount = (TextView) view.findViewById(R.id.tv_count);
        ImageView btn_add = (ImageView) view.findViewById(R.id.btn_add);
        btn_reduce.setOnClickListener(this);
        btn_add.setOnClickListener(this);
        //Set the default value
        int value = getValue();
        setValue(value);
    }

    @OnClick({R.id.btn_reduce, R.id.btn_add})
    public void onViewClicked(View view) {
        switch (view.getId()) {
            case R.id.btn_reduce://Less
                reduce();
                break;
            case R.id.btn_add://plus
                add();
                break;
        }
    }

    /**
           * If the current value is greater than the minimum value minus
     */
    private void reduce() {
        if (value > minValue) {
            value--;
        }
        setValue(value);
        if (onValueChangeListene != null) {
            onValueChangeListene.onValueChange(value);
        }
    }

    /**
           * If the current value is less than the minimum value, add
     */
    private void add() {
        if (value < maxValue) {
            value++;
        }
        setValue(value);
        if (onValueChangeListene != null) {
            onValueChangeListene.onValueChange(value);
        }
    }

    //Get specific value
    public int getValue() {
        String countStr = tvCount.getText().toString().trim();
        if (countStr != null) {
            value = Integer.valueOf(countStr);
        }
        return value;
    }

    public void setValue(int value) {
        this.value = value;
        tvCount.setText(value + "");
    }

    public int getMinValue() {
        return minValue;
    }

    public void setMinValue(int minValue) {
        this.minValue = minValue;
    }

    public int getMaxValue() {
        return maxValue;
    }

    public void setMaxValue(int maxValue) {
        this.maxValue = maxValue;
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_reduce://Less
                reduce();
                break;
            case R.id.btn_add://plus
                add();
                break;
        }
    }


    //Monitor callback
    public interface OnValueChangeListener {
        public void onValueChange(int value);
    }

    private OnValueChangeListener onValueChangeListene;

    public void setOnValueChangeListene(OnValueChangeListener onValueChangeListene) {
        this.onValueChangeListene = onValueChangeListene;
    }
}

Activity code

package adpickerview.zbxxjl.com.addersubtractor;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

import butterknife.Bind;
import butterknife.ButterKnife;

public class MainActivity extends AppCompatActivity {

    @Bind(R.id.adderview)
    adderView adderview;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);
        //monitor
        adderview.setOnValueChangeListene(new adderView.OnValueChangeListener() {
            @Override
            public void onValueChange(int value) {
                ToastUtils.show(MainActivity.this, value + "");
            }
        });
    }
}

Finally github address:https://github.com/787060894/adderSubtractor