Android计算器 Android实现简单计算器
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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;
}
}
}
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