Android Studio怎么实现简易计算器App
本篇内容主要讲解“Android Studio怎么实现简易计算器App”，感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷，实用性强。下面就让小编来带大家学习“Android Studio怎么实现简易计算器App”吧!
效果演示
布局文件
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent"> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="2" android:orientation="vertical"> <TextView android:id="@+id/mini" android:layout_width="match_parent" android:layout_height="wrap_content" android:textSize="40dp" android:text="" android:textDirection="rtl"/> <TextView android:id="@+id/max" android:layout_width="match_parent" android:layout_height="wrap_content" android:textSize="100dp" android:text="" android:textDirection="rtl"/> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1" android:orientation="horizontal"> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="%" android:textSize="30dp" android:onClick="surplus"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="CE" android:textSize="30dp" android:onClick="clearce"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="C" android:textSize="30dp" android:onClick="clearc"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="⇦" android:textSize="30dp" android:onClick="backsprce"/> </LinearLayout> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1" android:orientation="horizontal"> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="1/x" android:textSize="30dp" android:onClick="reciprocal"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="x²" android:textSize="30dp" android:onClick="square"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="²√x" android:textSize="30dp" android:onClick="squareroot"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="÷" android:textSize="60dp" android:onClick="division"/> </LinearLayout> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1" android:orientation="horizontal"> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="7" android:textSize="30dp" android:onClick="number_7"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="8" android:textSize="30dp" android:onClick="number_8"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="9" android:textSize="30dp" android:onClick="number_9"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="×" android:textSize="30dp" android:onClick="multiplication"/> </LinearLayout> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1" android:orientation="horizontal"> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="4" android:textSize="30dp" android:onClick="number_4"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="5" android:textSize="30dp" android:onClick="number_5"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="6" android:textSize="30dp" android:onClick="number_6"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="－" android:textSize="30dp" android:onClick="subtraction"/> </LinearLayout> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1" android:orientation="horizontal"> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="1" android:textSize="30dp" android:onClick="number_1"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="2" android:textSize="30dp" android:onClick="number_2"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="3" android:textSize="30dp" android:onClick="number_3"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="＋" android:textSize="30dp" android:onClick="addition"/> </LinearLayout> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1" android:orientation="horizontal"> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="±" android:textSize="30dp" android:onClick="change"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="0" android:textSize="30dp" android:onClick="number_0"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="." android:textSize="30dp"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_weight="1"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:text="＝" android:textSize="30dp" android:onClick="equal"/> </LinearLayout> </LinearLayout> </LinearLayout>
Java文件
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
import androidx.annotation.Nullable;
public class MainActivity extends Activity {
private TextView tv1;
private TextView tv2;
private StringBuilder viewStr;
private int index = 0;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_calc);
tv1 = (TextView) findViewById(R.id.mini);
tv2 = (TextView) findViewById(R.id.max);
viewStr = new StringBuilder();
index = 0;
}
//加减乘除、求余简单运算方法
public String calc(StringBuilder strB) {
String allS = strB.toString();
String[] asmd = {"＋","－","×","÷","%"};
int x = 0; int y = 0;
String result = null;
for (int i = 0; i < 5; i ++) {
int inde = strB.indexOf(asmd[i]);
if (inde > 0) {
String a = allS.split(asmd[i])[0];
String b = allS.split(asmd[i])[1];
if (i == 0) {result = String.valueOf(Integer.parseInt(a) + Integer.parseInt(b));}
if (i == 1) {result = String.valueOf(Integer.parseInt(a) - Integer.parseInt(b));}
if (i == 2) {result = String.valueOf(Integer.parseInt(a) * Integer.parseInt(b));}
if (i == 3) {
if (Integer.parseInt(b) == 0) {
Toast.makeText(this,"0不能为除数",Toast.LENGTH_SHORT).show();
result = String.valueOf(Integer.parseInt(a));
}else {
result = String.valueOf(Integer.parseInt(a) / Integer.parseInt(b));
}
}
if (i == 4) {result = String.valueOf(Integer.parseInt(a) % Integer.parseInt(b));}
}
}
return result;
}
//数字按钮事件
public void number_0(View view) { viewStr.append("0"); index ++ ; tv2.setText(viewStr); }
public void number_1(View view) { viewStr.append("1"); index ++ ; tv2.setText(viewStr); }
public void number_2(View view) { viewStr.append("2"); index ++ ; tv2.setText(viewStr); }
public void number_3(View view) { viewStr.append("3"); index ++ ; tv2.setText(viewStr); }
public void number_4(View view) { viewStr.append("4"); index ++ ; tv2.setText(viewStr); }
public void number_5(View view) { viewStr.append("5"); index ++ ; tv2.setText(viewStr); }
public void number_6(View view) { viewStr.append("6"); index ++ ; tv2.setText(viewStr); }
public void number_7(View view) { viewStr.append("7"); index ++ ; tv2.setText(viewStr); }
public void number_8(View view) { viewStr.append("8"); index ++ ; tv2.setText(viewStr); }
public void number_9(View view) { viewStr.append("9"); index ++ ; tv2.setText(viewStr); }
//回退按钮事件
public void backsprce(View view) {
if (viewStr.length() == 0) return;
index = viewStr.length();
viewStr.deleteCharAt(--index); tv2.setText(viewStr);
}
//符号改变按钮事件
public void change(View view) {
String allS = viewStr.toString();
String[] asmd = {"＋","－","×","÷","%"};
int inde = 0;
String a = null; //保存字符串中运算符部分
String b = null; //保存字符串中数字部分
for (int i = 0; i < 5; i ++) {
inde = viewStr.indexOf(asmd[i]);
if (inde != -1) {
a = asmd[i];
break;
}
}
//A 字符形 改变 A 正负值
if (inde == -1) {
clearc(view);
int c = - Integer.parseInt(allS);
viewStr.append(String.valueOf(c));
index = String.valueOf(c).length();
tv2.setText(viewStr);
}
//A + 字符串形 改变 A 正负值 暂时无法实现，待后续优化
if (inde == index - 1) {
return;
// clearc(view);
// int c = - Integer.valueOf(allS.split(a)[0]);
// viewStr.append(String.valueOf(c));
// index = String.valueOf(c).length();
// tv2.setText(viewStr);
}
//A + B 字符串形 改变 B 正负值
if (inde >= 0 && inde < index) {
clearc(view);
b = allS.split(a)[0];
int c = - Integer.parseInt(allS.split(a)[1]);
viewStr.append(b).append(a).append(String.valueOf(c));
index = String.valueOf(c).length();
tv2.setText(viewStr);
}
}
//清空按钮事件
public void clearc(View view) {
StringBuilder temp = new StringBuilder();
viewStr = temp.append("");
tv2.setText(viewStr);
index = 0;
}
public void clearce(View view) {
StringBuilder temp = new StringBuilder();
viewStr = temp.append("");
tv1.setText("");
tv2.setText(viewStr);
index = 0;
}
//等于按钮事件
public void equal(View view) {
String[] asmd = {"＋","－","×","÷","%"};
StringBuilder temp = new StringBuilder();
for (int i = 0; i < 5; i ++) {
int inde = viewStr.indexOf(asmd[i]);
if (inde > 0 && inde != index-1) {
tv1.setText(calc(viewStr));
String a = calc(viewStr);
viewStr = temp.append(a);
tv2.setText(viewStr);
index = viewStr.length();
return;
}else if (inde > 0 && inde == index-1) {
viewStr.deleteCharAt(--index);
tv1.setText(viewStr);
tv2.setText(viewStr);
}
}
tv1.setText(viewStr);
tv2.setText(viewStr);
}
//加减乘除按钮事件
public void addition(View view) {
if (viewStr.length() == 0) return;
String[] asmd = {"＋","－","×","÷","%"};
StringBuilder temp = new StringBuilder();
for (int i = 0; i < 5; i ++) {
int inde = viewStr.indexOf(asmd[i]);
if (inde > 0 && viewStr.charAt(index-1) >= '0' && viewStr.charAt(index-1) <= '9') {
tv1.setText(calc(viewStr));
String a = calc(viewStr);
viewStr = temp.append(a).append('＋');
tv2.setText(viewStr);
index = viewStr.length();
return;
}
}
char a = viewStr.charAt(index-1);
if (a == '＋') { return; }
if (a == '－' || a == '×' || a == '÷' || a == '%') {
viewStr.setCharAt(index-1,'＋');
}else {
viewStr.append("＋");
index ++ ;
}
tv2.setText(viewStr);
}
public void subtraction(View view) {
if (viewStr.length() == 0) return;
String[] asmd = {"＋","－","×","÷","%"};
StringBuilder temp = new StringBuilder();
for (int i = 0; i < 5; i ++) {
int inde = viewStr.indexOf(asmd[i]);
if (inde > 0 && viewStr.charAt(index-1) >= '0' && viewStr.charAt(index-1) <= '9') {
tv1.setText(calc(viewStr));
String a = calc(viewStr);
viewStr = temp.append(a).append('－');
tv2.setText(viewStr);
index = viewStr.length();
return;
}
}
char a = viewStr.charAt(index-1);
if (a == '－') { return; }
if (a == '＋' || a == '×' || a == '÷' || a == '%') {
viewStr.setCharAt(index-1,'－');
}else {
viewStr.append("－");
index ++ ;
}
tv2.setText(viewStr);
}
public void multiplication(View view) {
if (viewStr.length() == 0) return;
String[] asmd = {"＋","－","×","÷","%"};
StringBuilder temp = new StringBuilder();
for (int i = 0; i < 5; i ++) {
int inde = viewStr.indexOf(asmd[i]);
if (inde > 0 && viewStr.charAt(index-1) >= '0' && viewStr.charAt(index-1) <= '9') {
tv1.setText(calc(viewStr));
String a = calc(viewStr);
viewStr = temp.append(a).append('×');
tv2.setText(viewStr);
index = viewStr.length();
return;
}
}
char a = viewStr.charAt(index-1);
if (a == '×') { return; }
if (a == '＋' || a == '－' || a == '÷' || a == '%') {
viewStr.setCharAt(index-1,'×');
}else {
viewStr.append("×");
index ++ ;
}
tv2.setText(viewStr);
}
public void division(View view) {
if (viewStr.length() == 0) return;
String[] asmd = {"＋","－","×","÷","%"};
StringBuilder temp = new StringBuilder();
for (int i = 0; i < 5; i ++) {
int inde = viewStr.indexOf(asmd[i]);
if (inde > 0 && viewStr.charAt(index-1) >= '0' && viewStr.charAt(index-1) <= '9') {
tv1.setText(calc(viewStr));
String a = calc(viewStr);
viewStr = temp.append(a).append('÷');
tv2.setText(viewStr);
index = viewStr.length();
return;
}
}
char a = viewStr.charAt(index-1);
if (a == '÷') { return; }
if (a == '＋' || a == '－' || a == '×' || a == '%') {
viewStr.setCharAt(index-1,'÷');
}else {
viewStr.append("÷");
index ++ ;
}
tv2.setText(viewStr);
}
//求余按钮事件
public void surplus(View view) {
if (viewStr.length() == 0) return;
String[] asmd = {"＋","－","×","÷","%"};
StringBuilder temp = new StringBuilder();
for (int i = 0; i < 5; i ++) {
int inde = viewStr.indexOf(asmd[i]);
if (inde > 0 && viewStr.charAt(index-1) >= '0' && viewStr.charAt(index-1) <= '9') {
tv1.setText(calc(viewStr));
String a = calc(viewStr);
viewStr = temp.append(a).append('%');
tv2.setText(viewStr);
index = viewStr.length();
return;
}
}
char a = viewStr.charAt(index-1);
if (a == '%') { return; }
if (a == '＋' || a == '－' || a == '×' || a == '÷') {
viewStr.setCharAt(index-1,'%');
}else {
viewStr.append("%");
index ++ ;
}
tv2.setText(viewStr);
}
//求倒数按钮事件
public void reciprocal(View view) {
if (viewStr.length() == 0) return;
String[] asmd = {"＋","－","×","÷","%"};
for (int i = 0; i < 5; i ++) {
int inde = viewStr.indexOf(asmd[i]);
if (inde > -1) { return; }
}
int a = Integer.parseInt(viewStr.toString().trim());
if (a == 0) {
Toast.makeText(this,"0不能为除数",Toast.LENGTH_SHORT).show();
return;
}
clearc(view);
viewStr.append(1/a);
index = String.valueOf(1/a).length();
tv2.setText(viewStr);
}
//平方按钮事件
public void square(View view) {
if (viewStr.length() == 0) return;
String[] asmd = {"＋","－","×","÷","%"};
for (int i = 0; i < 5; i ++) {
int inde = viewStr.indexOf(asmd[i]);
if (inde > -1) { return; }
}
int a = Integer.parseInt(viewStr.toString().trim());
clearc(view);
viewStr.append(a*a);
index = String.valueOf(a*a).length();
tv2.setText(viewStr);
}
//开平方按钮事件
public void squareroot(View view) {
if (viewStr.length() == 0) return;
String[] asmd = {"＋","－","×","÷","%"};
for (int i = 0; i < 5; i ++) {
int inde = viewStr.indexOf(asmd[i]);
if (inde > -1) { return; }
}
int a = Integer.parseInt(viewStr.toString().trim());
clearc(view);
viewStr.append((int)Math.sqrt(a));
index = String.valueOf((int)Math.sqrt(a)).length();
tv2.setText(viewStr);
}
}到此，相信大家对“Android Studio怎么实现简易计算器App”有了更深的了解，不妨来实际操作一番吧！这里是蜗牛博客网站，更多相关内容可以进入相关频道进行查询，关注我们，继续学习！
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