计算器基本完成;

app/src/main/AndroidManifest.xml

 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-          package="com.xingdata.zzdpos">
+    package="com.xingdata.zzdpos">
 
-    <uses-permission android:name="android.permission.INTERNET"/>
-    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
-    <uses-permission android:name="android.permission.SEND_SMS"/>
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
+    <uses-permission android:name="android.permission.SEND_SMS" />
 
     <application
         android:name=".App"
@@ -19,18 +19,15 @@
             android:configChanges="keyboard|orientation|screenSize|keyboardHidden"
             android:label="@string/main_title"
             android:launchMode="singleTask"
-            android:windowSoftInputMode="adjustUnspecified|stateHidden" >
-            <intent-filter>
-                <action android:name="android.intent.action.MAIN"/>
+            android:windowSoftInputMode="adjustUnspecified|stateHidden">
 
-                <category android:name="android.intent.category.LAUNCHER"/>
-            </intent-filter>
         </activity>
 
         <activity
             android:name=".ui.splash.SplashActivity"
             android:configChanges="keyboard|orientation|screenSize|keyboardHidden"
             android:theme="@style/AppTheme">
+
         </activity>
 
         <activity
@@ -49,7 +46,13 @@
         <activity
             android:name=".ui.payment.PaymentActivity"
             android:configChanges="keyboard|orientation|screenSize|keyboardHidden"
-            android:windowSoftInputMode="adjustUnspecified|stateHidden" />
+            android:windowSoftInputMode="adjustUnspecified|stateHidden">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
     </application>
 
 </manifest>
\ No newline at end of file

app/src/main/java/com/xingdata/zzdpos/ui/payment/fragment/PaymentFragment.java

@@ -23,6 +23,8 @@ public class PaymentFragment extends BaseFragment<PaymentPresenter, FragmentPaym
 
         mCalculatorView.setmOnResultChangeListener((exp, result) -> {
             LogUtils.e(exp + "\n" + result);
+            mViewBinding.tvExp.setText(exp);
+            mViewBinding.tvResult.setText(ConvertUtil.fenToYuan(result));
         });
         mCalculatorView.setmOnSettleClickListener(result -> {
             LogUtils.e(ConvertUtil.fenToYuan(result));

app/src/main/java/com/xingdata/zzdpos/ui/payment/view/CalculatorView.java

@@ -4,6 +4,7 @@ package com.xingdata.zzdpos.ui.payment.view;
 import android.view.View;
 import android.widget.TextView;
 
+import com.blankj.utilcode.util.LogUtils;
 import com.xingdata.zzdpos.R;
 import com.xingdata.zzdpos.base.BaseFragment;
 import com.xingdata.zzdpos.databinding.ViewCalculatorBinding;
@@ -18,6 +19,7 @@ public class CalculatorView extends BaseFragment<PaymentPresenter, ViewCalculato
 
     private String mExp;
     private String mValue;
+    private String mLast;
 
     private OnResultChangeListener mOnResultChangeListener;
     private onSettleClickListener mOnSettleClickListener;
@@ -26,6 +28,7 @@ public class CalculatorView extends BaseFragment<PaymentPresenter, ViewCalculato
     public CalculatorView() {
         mExp = "";
         mValue = "";
+        mLast = "";
     }
 
     public interface OnResultChangeListener {
@@ -55,24 +58,28 @@ public class CalculatorView extends BaseFragment<PaymentPresenter, ViewCalculato
                     settle();
                     break;
                 default:
+                    LogUtils.e("mExp : " + mExp + "\nmValue : " + mValue + "\nmLast" + mLast);
                     if (view instanceof TextView) {
                         String str = ((TextView) view).getText().toString();
-                        if (mExp.length() == 0 && str.matches("[+\\-*/]")) return;
-                        if (mExp.length() == 0 && str.equals(".")) mExp += "0";
 
-                        if (mValue.length() > 0 && str.matches("[+\\-*/]")) {
+                        String[] mExps = mExp.split("[+\\-×÷]");
+
+                        if (mExps.length > 1) mValue = mExps[mExps.length - 1];
+                        else mValue = mExp;
+
+                        if (mLast.matches("[+\\-×÷.]") && str.matches("[+\\-×÷.]")) return;
+
+                        if (mValue.length() > 0 && str.matches("[+\\-×÷]")) {
                             mValue = "";
                         } else {
-                            if (mValue.contains(".") && str.matches("[.]")) return;
-
-                            mValue += str;
-                            String[] _values = mValue.split("[.]");
-                            if (_values.length > 1) {
-                                if (_values[1].length() > 2) return;
-                            }
+                            if (mValue.length() == 0 && str.matches("[+\\-×÷]")) return;
+                            if (mValue.contains(".") && str.matches("[+\\-×÷.]")) return;
+                            if (mValue.split("[.]").length > 1 && mValue.split("[.]")[1].length() > 2)
+                                return;
+                            if (mValue.length() == 0 && str.equals(".")) mExp += "0";
                         }
 
-
+                        mLast = str;
                         mExp += str;
                     }
                     break;
@@ -88,7 +95,10 @@ public class CalculatorView extends BaseFragment<PaymentPresenter, ViewCalculato
      * 删除
      */
     private void delete() {
-        mExp = mExp.substring(0, mExp.length() - 1);
+        if (mExp.length() > 0) {
+            mExp = mExp.substring(0, mExp.length() - 1);
+            mLast = mExp.substring(mExp.length() - 1, mExp.length());
+        }
     }
 
     /**
@@ -124,12 +134,11 @@ public class CalculatorView extends BaseFragment<PaymentPresenter, ViewCalculato
                 .replaceAll("×", "*").replaceAll("÷", "/");
         String minExp = "^((\\d+(\\.\\d+)?)|(\\[-\\d+(\\.\\d+)?]))[+\\-*/]((\\d+(\\.\\d+)?)|(\\[-\\d+(\\.\\d+)?]))$";
         if (exp.matches(minExp)) {
-            String result = calculate(exp);
-            return Double.parseDouble(result) >= 0 ? result : "[" + result + "]";
+            return calculate(exp);
         } else if (exp.matches("[0-9.]+")) {
             return exp;
         } else if (exp.length() == 0) {
-            return "0";
+            return "0.0";
         }
         String noParentheses = "^[^()]+$";
         String priorOperatorExp = "(((\\d+(\\.\\d+)?)|(\\[-\\d+(\\.\\d+)?]))[*/]((\\d+(\\.\\d+)?)|(\\[-\\d+(\\.\\d+)?])))";
@@ -143,7 +152,6 @@ public class CalculatorView extends BaseFragment<PaymentPresenter, ViewCalculato
             } else {
                 patt = Pattern.compile(operatorExp);
                 mat = patt.matcher(exp);
-
                 if (mat.find()) {
                     String tempMinExp = mat.group();
                     exp = exp.replaceFirst(operatorExp, parseExp(tempMinExp));

app/src/main/res/layout/fragment_payment.xml

@@ -6,6 +6,7 @@
         android:layout_height="match_parent"
         android:orientation="vertical">
 
+
         <LinearLayout
             android:layout_width="match_parent"
             android:layout_height="0dp"
@@ -13,6 +14,20 @@
             android:background="@color/store_product_bg"
             android:orientation="vertical">
 
+
+            <TextView
+                android:id="@+id/tv_exp"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:gravity="end|center_vertical"
+                android:textColor="@color/white_caocao" />
+
+            <TextView
+                android:id="@+id/tv_result"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:gravity="end|center_vertical"
+                android:textColor="@color/white_caocao" />
         </LinearLayout>
 
         <LinearLayout