Fixed for https://gitee.com/beikeshop/beikeshop/issues/I70XJW?from=project-issue

beike/Admin/Http/Controllers/CurrencyController.php

@@ -12,6 +12,7 @@
 namespace Beike\Admin\Http\Controllers;
 
 use Beike\Admin\Http\Requests\CurrencyRequest;
+use Beike\Models\Order;
 use Beike\Repositories\CurrencyRepo;
 use Illuminate\Http\Request;
 
@@ -66,9 +67,19 @@ class CurrencyController extends Controller
 
     public function destroy(Request $request, int $currencyId)
     {
+        try {
+            $currency   = CurrencyRepo::find($currencyId);
+            $orderExist = Order::query()->where('currency_code', $currency->code)->exists();
+            if ($orderExist) {
+                throw new \Exception(trans('admin/currency.order_exist'));
+            }
+
             CurrencyRepo::delete($currencyId);
             hook_action('admin.currency.destroy.after', $currencyId);
 
             return json_success(trans('common.deleted_success'));
+        } catch (\Exception $e) {
+            return json_fail($e->getMessage());
+        }
     }
 }

beike/Services/CurrencyService.php

@@ -42,12 +42,17 @@ class CurrencyService
             return $amount;
         }
 
-        $symbol_left   = $this->currencies[$currency]->symbol_left;
-        $symbol_right  = $this->currencies[$currency]->symbol_right;
-        $decimal_place = $this->currencies[$currency]->decimal_place;
+        $currencyRow = $this->currencies[$currency] ?? null;
+        if (empty($currencyRow)) {
+            return $amount;
+        }
+
+        $symbol_left   = $currencyRow->symbol_left;
+        $symbol_right  = $currencyRow->symbol_right;
+        $decimal_place = $currencyRow->decimal_place;
 
         if (! $value) {
-            $value = $this->currencies[$currency]->value;
+            $value = $currencyRow->value;
         }
 
         $amount = $value ? (float) $amount * $value : (float) $amount;

resources/lang/en/admin/currency.php

@@ -16,4 +16,5 @@ return [
     'currencies_show'   => 'Detail',
     'currencies_update' => 'Edit',
     'currencies_delete' => 'Delete',
+    'order_exist' => 'This currency has orders in use and cannot be deleted!',
 ];

resources/lang/zh_cn/admin/currency.php

@@ -16,4 +16,6 @@ return [
     'currencies_show'   => '货币详情',
     'currencies_update' => '更新货币',
     'currencies_delete' => '删除货币',
+
+    'order_exist' => '该货币有订单正在使用, 无法删除!',
 ];

resources/lang/zh_hk/admin/currency.php

@@ -16,4 +16,5 @@ return [
     'currencies_show'   => '貨幣詳情',
     'currencies_update' => '更新貨幣',
     'currencies_delete' => '刪除貨幣',
+    'order_exist' => '該貨幣有訂單正在使用，無法删除！',
 ];