refactor(Modal): keep body original style

Author: ArgoZhang

src/BootstrapBlazor/Components/Modal/Modal.razor.js

@@ -12,7 +12,8 @@ export function init(id, invoke, shownCallback, closeCallback) {
             if (modal) {
                 modal.hide();
             }
-        }
+        },
+        originalStyle: null
     }
     Data.set(id, modal)
 
@@ -33,6 +34,7 @@ export function init(id, invoke, shownCallback, closeCallback) {
     EventHandler.on(window, 'popstate', modal.pop)
 
     modal.show = () => {
+        modal.originalStyle ??= document.body.style;
         const dialogs = el.querySelectorAll('.modal-dialog')
         if (dialogs.length === 1) {
             let backdrop = el.getAttribute('data-bs-backdrop') !== 'static'
@@ -61,6 +63,8 @@ export function init(id, invoke, shownCallback, closeCallback) {
     modal.hide = () => {
         if (el.children.length === 1) {
             modal.modal.hide();
+            document.body.style = modal.originalStyle;
+            modal.originalStyle = null;
         }
         else {
             modal.invoke.invokeMethodAsync(modal.closeCallback)
@@ -143,6 +147,11 @@ export function dispose(id) {
                 dialog._backdrop._config.isAnimated = false;
                 dialog._hideModal();
             }
+
+            if(modal.originalStyle) {
+                document.body.style = modal.originalStyle;
+                modal.originalStyle = null;
+            }
             dialog.dispose()
         }
     }