自定义加减器

1. 自定义MyView 继承LinearLayout

package com.bw.shoppingpractice;

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

public class MyView extends LinearLayout implements View.OnClickListener {

    private Button add;
    private Button jian;
    private TextView textView;
     private int i=1;
    public MyView(Context context) {
        super(context);
    }

    public MyView(Context context, AttributeSet attrs) {
        super(context, attrs);
        LayoutInflater.from(context).inflate(R.layout.myview,this);
        add = findViewById(R.id.button1);
        jian = findViewById(R.id.button2);
         textView = findViewById(R.id.text1);
         add.setOnClickListener(this);
         jian.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.button1:
                i++;
                textView.setText("" + i);
                break;
            case R.id.button2:
                if (i > 1) {
                    i--;
                    textView.setText("" + i);
                } else
                {
                    Toast.makeText(getContext(),"不能再减了",Toast.LENGTH_SHORT).show();
                }
                break;
        }
    }
}

1.在你需要的地方写上布局

<com.bw.shoppingpractice.MyView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="40dp"
    android:layout_marginTop="70dp"
    android:id="@+id/myview"
    ></com.bw.shoppingpractice.MyView>

1. 加减器的布局

<?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"
    >
  <Button
      android:layout_width="50dp"
      android:layout_height="50dp"
      android:text="+"
      android:id="@+id/button1"
      />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="1"
        android:textSize="25dp"
        android:id="@+id/text1"
        />
    <Button
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:text="-"
        android:id="@+id/button2"

        />
</LinearLayout>

标签：自定义,加减器,private,public,context,import,android,id
来源： https://blog.csdn.net/weixin_44329686/article/details/89010296