Android实现简单计算器

本文实例为大家分享了android实现简单计算器的具体代码，供大家参考，具体内容如下

功能

1、加减乘除四则运算
2、归0
3、回退
4、即时运算

配置

在build.gradle(app) 中加入下面的代码

buildfeatures {
        viewbinding = true
    }

加入位置如下所示

compileoptions {
        sourcecompatibility javaversion.version_1_8
        targetcompatibility javaversion.version_1_8
    }
buildfeatures {
    viewbinding = true
}

布局

<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    >
    <textview
        android:id="@+id/tv"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="4"
        android:layout_margin="5dp"
        android:text="计算器\nby csdn weixin_44423317 "
        android:textsize="20sp"
        android:gravity="right|center"
        android:padding="6dp"
        />
    <view
        android:layout_width="match_parent"
        android:layout_height="2dp"
        android:layout_marginleft="1dp"
        android:layout_marginright="1dp"
        android:background="#adadad"/>
    <linearlayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="8"
        android:orientation="vertical"
        android:gravity="center_horizontal"
        >
        <linearlayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:orientation="horizontal">
            <button
                android:id="@+id/ac"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:textsize="20sp"
                android:textcolor="@color/black"
                android:text="ac"
                android:background="@color/white"/>
            <button
                android:layout_weight="1"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:background="#00ffffff"/>
            <button
                android:layout_weight="1"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:background="#00ffffff"/>
            <imagebutton
                android:id="@+id/dec"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="match_parent"
                android:textsize="20sp"
                android:textcolor="@color/black"
                android:layout_gravity="right"
                android:background="@color/white"
                android:src="@drawable/ic_baseline_backspace_24"/>
        </linearlayout>
        <linearlayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:orientation="horizontal">
            <button
                android:id="@+id/qi"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="match_parent"
                android:textsize="20sp"
                android:textcolor="@color/black"
                android:text="7"
                android:background="@color/white"/>
            <button
                android:id="@+id/ba"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="match_parent"
                android:textsize="20sp"
                android:textcolor="@color/black"
                android:text="8"
                android:background="@color/white"/>
            <button
                android:id="@+id/jiu"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="match_parent"
                android:textcolor="@color/black"
                android:text="9"
                android:textsize="20sp"
                android:background="@color/white"/>
            <button
                android:id="@+id/mul"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="match_parent"
                android:textsize="20sp"
                android:textcolor="@color/black"
                android:text="x"
                android:background="@color/white"/>
        </linearlayout>
        <linearlayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:orientation="horizontal">
            <button
                android:id="@+id/si"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:textsize="20sp"
                android:layout_height="match_parent"
                android:textcolor="@color/black"
                android:text="4"
                android:background="@color/white"/>
            <button
                android:id="@+id/wu"
                android:textsize="20sp"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="match_parent"
                android:textcolor="@color/black"
                android:text="5"
                android:background="@color/white"/>
            <button
                android:id="@+id/liu"
                android:textsize="20sp"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="match_parent"
                android:textcolor="@color/black"
                android:text="6"
                android:background="@color/white"/>
            <button
                android:id="@+id/div"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:textsize="20sp"
                android:layout_height="match_parent"
                android:textcolor="@color/black"
                android:text="/"
                android:background="@color/white"/>
        </linearlayout>
        <linearlayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:orientation="horizontal">
            <button
                android:id="@+id/yi"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:textsize="20sp"
                android:layout_height="match_parent"
                android:textcolor="@color/black"
                android:text="1"
                android:background="@color/white"/>
            <button
                android:id="@+id/er"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="match_parent"
                android:textsize="20sp"
                android:textcolor="@color/black"
                android:text="2"
                android:background="@color/white"/>
            <button
                android:id="@+id/san"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="match_parent"
                android:textcolor="@color/black"
                android:textsize="20sp"
                android:text="3"
                android:background="@color/white"/>
            <button
                android:id="@+id/sub"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="match_parent"
                android:textcolor="@color/black"
                android:textsize="20sp"
                android:text="-"
                android:background="@color/white"/>
        </linearlayout>
        <linearlayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:orientation="horizontal">
            <button
                android:id="@+id/zero"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="match_parent"
                android:textcolor="@color/black"
                android:textsize="20sp"
                android:text="0"
                android:background="@color/white"/>
            <button
                android:id="@+id/point"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="match_parent"
                android:textcolor="@color/black"
                android:textsize="20sp"
                android:text="."
                android:background="@color/white"/>
            <button
                android:id="@+id/equal"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="match_parent"
                android:textcolor="@color/black"
                android:textsize="20sp"
                android:text="="
                android:background="@color/white"/>
            <button
                android:id="@+id/add"
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="match_parent"
                android:textcolor="@color/black"
                android:textsize="20sp"
                android:text="+"
                android:background="@color/white"/>
        </linearlayout>
    </linearlayout>
</linearlayout>

代码

public class mainactivity extends appcompatactivity implements view.onclicklistener {
    private string tv="0";
    private activitymainbinding inflate;
    private string count="";
    private boolean ismax=false;
    @override
    protected void oncreate(bundle savedinstancestate) {
        super.oncreate(savedinstancestate);
        inflate = activitymainbinding.inflate(getlayoutinflater());
        setcontentview(inflate.getroot());
        inflate.zero.setonclicklistener(this);
        inflate.yi.setonclicklistener(this);
        inflate.er.setonclicklistener(this);
        inflate.san.setonclicklistener(this);
        inflate.si.setonclicklistener(this);
        inflate.wu.setonclicklistener(this);
        inflate.liu.setonclicklistener(this);
        inflate.qi.setonclicklistener(this);
        inflate.ba.setonclicklistener(this);
        inflate.jiu.setonclicklistener(this);
        inflate.add.setonclicklistener(this);
        inflate.sub.setonclicklistener(this);
        inflate.mul.setonclicklistener(this);
        inflate.div.setonclicklistener(this);
        inflate.point.setonclicklistener(this);
        inflate.equal.setonclicklistener(this);
        inflate.dec.setonclicklistener(this);
        inflate.ac.setonclicklistener(this);
    }
    private void jisuanqi(){
        list<string> strs=new arraylist<>();
        stringbuilder f= new stringbuilder();
        for(int i=0;i<tv.length();i++) {
            if(string.valueof(tv.charat(i)).equals("-")) {
                if(!f.tostring().equals("")){
                    strs.add(f.tostring());
                    strs.add("-");
                    f = new stringbuilder();
                }else{
                    f.append("-");
                }
                continue;
            }
            if(string.valueof(tv.charat(i)).matches("(\\d+)|(\\.)")) {
                f.append(string.valueof(tv.charat(i)));
            }else {
                strs.add(f.tostring());
                strs.add(string.valueof(tv.charat(i)));
                f = new stringbuilder();
            }
        }
        if(!f.tostring().equals("")) {
            strs.add(f.tostring());
        }
        if(!strs.get(strs.size()-1).matches("(\\-|)?\\d+(\\.\\d*)?$")){
            strs.remove(strs.size()-1);
        }
        double ans=number(strs,0);
        if(ans==0||ans%(int)ans==0){
            count=(int)ans+"";
        }else {
            bigdecimal bigdecimal=new bigdecimal(ans);
            string a=bigdecimal.setscale(12,5).tostring();
            if(ans-(int)ans!=0) {
                while (string.valueof(a.charat(a.length() - 1)).equals("0")){
                    a=a.substring(0,a.length()-1);
                }
            }
            count=a;
        }
        if(ismax){
            ismax=false;
            count="∞";
        }
        showtext();
    }
    private void showtext(){
        inflate.tv.settext(tv);
        spannablestring spantext  =  new spannablestring(count);
        spantext.setspan(new absolutesizespan(30, true), 0, spantext.length(),
                spannable.span_exclusive_exclusive);
        inflate.tv.append("\n");
        inflate.tv.append(spantext);
    }
    private double number(list<string> n,int v) {
        double con = 0;
        int j=0;
        con=double.valueof(n.get(0));
        if(v==0) {
            for(int i=0;i<n.size();i++) {
                if(n.get(i).matches("(\\-|)?\\d+(\\.\\d+)?$")) {//55+5*5/5-5=
                    con=double.valueof(n.get(i));
                    if(n.size()>i+1) {
                        j=i+1;
                    }
                }
                if(n.get(j).equals("x")){
                    n.set(i, string.valueof(con*double.valueof(n.get(i+2))));
                    n.remove(i+1);
                    n.remove(i+1);
                    return number(n,0);
                }else if(n.get(j).equals("/")){
                    if(double.valueof(n.get(i+2))==0){
                        ismax=true;
                        return 10;
                    }
                    n.set(i, string.valueof(con/double.valueof(n.get(i+2))));
                    n.remove(i+1);
                    n.remove(i+1);
                    return number(n,0);
                }
            }
        }
        for(int i=0;i<n.size();i++) {
            if(n.get(i).matches("(\\-|)?\\d+(\\.\\d+)?$")) {//55+5*5/5-5=
                con=double.valueof(n.get(i));
                if(n.size()>i+1) {
                    j=i+1;
                }
            }
            if(n.get(j).equals("+")){
                n.set(i, string.valueof(con+double.valueof(n.get(i+2))));
                n.remove(i+1);
                n.remove(i+1);
                return number(n,1);

            }else if(n.get(j).equals("-")){
                n.set(i, string.valueof(con-double.valueof(n.get(i+2))));
                n.remove(i+1);
                n.remove(i+1);
                return number(n,1);
            }

        }
        return con;
    }

    @suppresslint("nonconstantresourceid")
    @override
    public void onclick(view v) {

        switch (v.getid()){
            case r.id.point:
                if(string.valueof(tv.charat(tv.length()-1)).matches("\\d+")){
                    tv+=".";
                    inflate.tv.settext(tv);
                }
                break;
            case r.id.zero:
            case r.id.yi:
            case r.id.er:
            case r.id.san:
            case r.id.si:
            case r.id.wu:
            case r.id.liu:
            case r.id.qi:
            case r.id.ba:
            case r.id.jiu:
                if(tv.equals("0")){
                    tv="";
                }
                button bt_digit=findviewbyid(v.getid());
                tv+=bt_digit.gettext();
                inflate.tv.settext(tv);
                count=tv;
                jisuanqi();
                break;
            case r.id.sub:
                if(string.valueof(tv.charat(0)).equals("0")){
                    tv="-";
                }else {
                    if(string.valueof(tv.charat(tv.length()-1)).equals(".")){
                        tv += "0";
                    }
                    tv+="-";
                }
                showtext();
                break;
            case r.id.add:
            case r.id.mul:
            case r.id.div:
                button bt_operator=findviewbyid(v.getid());
                string laststr=string.valueof(tv.charat(tv.length()-1));
                if(!laststr.matches("(\\d+)") ) {
                    tv = tv.substring(0, tv.length() - 1) + bt_operator.gettext();
                }else {
                    if(laststr.equals(".")) {
                        tv += "0";
                    }
                    tv+=bt_operator.gettext();
                }

                showtext();
                break;
            case r.id.ac:
                tv="0";
                inflate.tv.settext(tv);
                break;
            case r.id.dec:
                if(tv.length()>1) {
                    tv = tv.substring(0, tv.length() - 1);
                }else {
                    tv="0";
                }
                jisuanqi();
                break;
            case r.id.equal:
                if(!string.valueof(tv.charat(tv.length()-1)).matches("(\\d+)")){
                    tv = tv.substring(0, tv.length() - 1);
                }
                count=tv;
                jisuanqi();
                tv=count;
                inflate.tv.settext(tv);
                break;
        }
    }
 }

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。